Merge remote branch 'origin/usrp_e_next' into usrp_e_next

129 files changed, 6395 insertions, 2743 deletions

diff --git a/host/AUTHORS b/host/AUTHORS
index e0775f3a1..512d4752e 100644
--- a/host/AUTHORS
+++ b/host/AUTHORS
@@ -24,6 +24,7 @@ Tom Tsou - ttsou@vt.edu
     USRP1 host code
     USRP1 firmware
 
-Nick Foster - nick@nerdnetworks.org
+Nick Foster - nick@ettus.com
     LIBUSB host code
     USRP1 host code
+    TVRX host code
diff --git a/host/CMakeLists.txt b/host/CMakeLists.txt
index 6c96706a5..e5ce78782 100644
--- a/host/CMakeLists.txt
+++ b/host/CMakeLists.txt
@@ -84,7 +84,7 @@ IF(UNIX AND EXISTS "/usr/lib64")
     LIST(APPEND BOOST_LIBRARYDIR "/usr/lib64") #fedora 64-bit fix
 ENDIF(UNIX AND EXISTS "/usr/lib64")
 
-SET(Boost_ADDITIONAL_VERSIONS "1.42.0" "1.42" "1.43.0" "1.43")
+SET(Boost_ADDITIONAL_VERSIONS "1.42.0" "1.42" "1.43.0" "1.43" "1.44.0" "1.44")
 FIND_PACKAGE(Boost ${BOOST_MIN_VERSION} REQUIRED COMPONENTS
     date_time
     filesystem
diff --git a/host/README b/host/README
index 5018ef541..cab1e0b10 100644
--- a/host/README
+++ b/host/README
@@ -6,7 +6,8 @@ The hardware driver for Ettus Research products.
 ########################################################################
 # Supported USRP Motherboards
 ########################################################################
-USRP2 - udp over gigabit ethernet
+USRP1
+USRP2
 
 ########################################################################
 # Supported USRP Daughterboards
@@ -19,6 +20,7 @@ RFX Series
 XCVR 2450
 WBX Series
 DBSRX
+TVRX
 
 ########################################################################
 # Documentation
diff --git a/host/apps/omap_debug/usrp_e.h b/host/apps/omap_debug/usrp_e.h
index fd38027d4..f96706c4a 100644
--- a/host/apps/omap_debug/usrp_e.h
+++ b/host/apps/omap_debug/usrp_e.h
@@ -41,6 +41,9 @@ struct usrp_e_ctl32 {
 #define UE_SPI_PUSH_FALL	UE_SPI_CTRL_TXNEG
 #define UE_SPI_LATCH_RISE	0
 #define UE_SPI_LATCH_FALL	UE_SPI_CTRL_RXNEG
+#define USRP_E_GET_COMPAT_NUMBER _IO(USRP_E_IOC_MAGIC, 0x28)
+
+#define USRP_E_COMPAT_NUMBER 1
 
 struct usrp_e_spi {
 	__u8 readback;
diff --git a/host/docs/CMakeLists.txt b/host/docs/CMakeLists.txt
index bbb8812b0..65db3befc 100644
--- a/host/docs/CMakeLists.txt
+++ b/host/docs/CMakeLists.txt
@@ -25,6 +25,7 @@ SET(manual_sources
     dboards.rst
     general.rst
     images.rst
+    transport.rst
     usrp1.rst
     usrp2.rst
 )
diff --git a/host/docs/build.rst b/host/docs/build.rst
index f37b5dce7..a41ce8331 100644
--- a/host/docs/build.rst
+++ b/host/docs/build.rst
@@ -47,7 +47,7 @@ CMake
 Boost
 ^^^^^^^^^^^^^^^^
 * **Purpose:** C++ library
-* **Version:** at least 3.6 unix, at least 4.0 windows
+* **Version:** at least 1.36 unix, at least 1.40 windows
 * **Usage:** build time + run time (required)
 * **Download URL:** http://www.boost.org/users/download/
 * **Download URL (windows installer):** http://www.boostpro.com/download
@@ -58,7 +58,8 @@ LibUSB
 * **Purpose:** USB-based hardware support
 * **Version:** at least 1.0
 * **Usage:** build time + run time (optional)
-* **Download URL:** http://www.libusb.org/
+* **Download URL:** http://sourceforge.net/projects/libusb/files/libusb-1.0/
+* **Download URL (windows binaries):** http://www.libusb.org/wiki/windows_backend#LatestBinarySnapshots
 
 ^^^^^^^^^^^^^^^^
 Python
@@ -152,6 +153,19 @@ Generate the project with cmake
 * Click generate and a project file will be created in the build directory.
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LibUSB cmake notes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+On Windows, cmake does not have the advantage of pkg-config,
+so we must manually tell cmake how to locate the LibUSB header and lib.
+
+From the cmake gui, select "Advanded View":
+
+* Set LIBUSB_INCLUDE_DIR to the directory with "libusb.h".
+* Set LIBUSB_LIBRARIES to the full path for "libusb-1.0.lib".
+
+Then check the boxes to enable USRP1 support, click configure and generate.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Build the project in MSVC
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 * Open the generated project file in MSVC.
@@ -177,3 +191,8 @@ Setup the PATH environment variable
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 * Add the boost library path to %PATH% (usually c:\\program files\\boost\\<version>\\lib)
 * Add the uhd library path to %PATH% (usually c:\\program files\\uhd\\lib)
+* Add the libusb library to %PATH% (if using usb support)
+
+**Note:**
+The interface for editing environment variable paths in Windows is very poor.
+I recommend using "Rapid Environment Editor" (http://www.rapidee.com) over the default editor.
diff --git a/host/docs/coding.rst b/host/docs/coding.rst
index d6a19d250..7533445ea 100644
--- a/host/docs/coding.rst
+++ b/host/docs/coding.rst
@@ -41,13 +41,13 @@ The single usrp provides ways to:
 See the documentation in *usrp/single_usrp.hpp* for reference.
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-High-Level: The mimo usrp
+High-Level: The multi usrp
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-The mimo usrp API provides a wrapper around a device that represents several motherboards.
+The multi usrp API provides a wrapper around a device that represents several motherboards.
 This API provides convenience calls just like the single usrp,
 however the calls either work across all channels in the configuration,
 or take a channel argument to specify which channel to configure.
-The mimo usrp provides ways to:
+The multi usrp provides ways to:
 
 * Set and get the sample rate across all channels.
 * Issue a stream command across all channels.
@@ -57,7 +57,7 @@ The mimo usrp provides ways to:
 * Tune individual DSPs and daughterboards.
 * Get the underlying device (as discussed above).
 
-See the documentation in *usrp/mimo_usrp.hpp* for reference.
+See the documentation in *usrp/multi_usrp.hpp* for reference.
 
 ------------------------------------------------------------------------
 Integrating custom hardware
diff --git a/host/docs/dboards.rst b/host/docs/dboards.rst
index 738a0696d..d93fb9d6a 100644
--- a/host/docs/dboards.rst
+++ b/host/docs/dboards.rst
@@ -26,6 +26,10 @@ The boards have no tunable elements or programmable gains.
 Though the magic of aliasing, you can down-convert signals
 greater than the Nyquist rate of the ADC.
 
+BasicRX Bandwidth (Hz): 250M
+
+LFRX Bandwidth (Hz): 30M
+
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Basic TX and and LFTX
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -40,6 +44,10 @@ The boards have no tunable elements or programmable gains.
 Though the magic of aliasing, you can up-convert signals
 greater than the Nyquist rate of the DAC.
 
+BasicTX Bandwidth (Hz): 250M
+
+LFTX Bandwidth (Hz): 30M
+
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 DBSRX
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -49,10 +57,12 @@ Receive Antennas: **J3**
 
 The board has no user selectable antenna setting
 
-Recieve Gains: 
+Receive Gains: 
     **GC1**, Range: 0-56dB
     **GC2**, Range: 0-24dB
 
+Bandwidth (Hz): 8M-66M
+
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 RFX Series
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -64,26 +74,29 @@ The user may set the receive antenna to be TX/RX or RX2.
 However, when using an RFX board in full-duplex mode,
 the receive antenna will always be set to RX2, regardless of the settings.
 
-Recieve Gains: **PGA0**, Range: 0-70dB (except RFX400 range is 0-45dB)
+Receive Gains: **PGA0**, Range: 0-70dB (except RFX400 range is 0-45dB)
+
+Bandwidths (Hz):
+ * **RX**: 40M
+ * **TX**: 40M
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 XCVR 2450
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-The XCVR2450 has a non-contiguous tuning range consisting of a high band and a low band.
-The high band consists of frequencies between...TODO
+The XCVR2450 has a non-contiguous tuning range consisting of a 
+high band (4.9-6.0GHz) and a low band (2.4-2.5GHz).
 
 Transmit Antennas: **J1** or **J2**
 
 Receive Antennas: **J1** or **J2**
 
-When using the XCVR2450 in full-duplex mode,
-the user must set the receive antenna and the transmit antenna to be different;
-not doing so will yeild undefined results.
-
 The XCVR2450 uses a common LO for both receive and transmit.
 Even though the API allows the RX and TX LOs to be individually set,
 a change of one LO setting will be reflected in the other LO setting.
 
+The XCVR2450 does not support full-duplex mode, attempting to operate 
+in full-duplex will result in transmit-only operation.
+
 Transmit Gains:
  * **VGA**, Range: 0-30dB
  * **BB**, Range: 0-5dB
@@ -92,6 +105,10 @@ Receive Gains:
  * **LNA**, Range: 0-30.5dB
  * **VGA**, Range: 0-62dB
 
+Bandwidths (Hz):
+ * **RX**: 15M, 19M, 28M, 36M; (each +-0, 5, or 10%)
+ * **TX**: 24M, 36M, 48M
+
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 WBX Series
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -105,7 +122,22 @@ the receive antenna will always be set to RX2, regardless of the settings.
 
 Transmit Gains: **PGA0**, Range: 0-25dB
 
-Recieve Gains: **PGA0**, Range: 0-31.5dB
+Receive Gains: **PGA0**, Range: 0-31.5dB
+
+Bandwidths (Hz):
+ * **RX**: 40M
+ * **TX**: 40M
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+TVRX
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Receive Antennas: RX
+
+Receive Gains:
+ * **RF**, Range: -13.3-50.3dB (frequency-dependent)
+ * **IF**, Range: -1.5-32.5dB
+
+Bandwidth: 6MHz
 
 ------------------------------------------------------------------------
 Daughterboard Modifications
diff --git a/host/docs/index.rst b/host/docs/index.rst
index bd55edc0b..7f8129e2d 100644
--- a/host/docs/index.rst
+++ b/host/docs/index.rst
@@ -20,11 +20,12 @@ Building the UHD
 ^^^^^^^^^^^^^^^^^^^^^
 Application Notes
 ^^^^^^^^^^^^^^^^^^^^^
-* `General App Notes <./general.html>`_
+* `General Application Notes <./general.html>`_
 * `Firmware and FPGA Image Notes <./images.html>`_
-* `USRP1 App Notes <./usrp1.html>`_
-* `USRP2 App Notes <./usrp2.html>`_
-* `Daughterboard App Notes <./dboards.html>`_
+* `USRP1 Application Notes <./usrp1.html>`_
+* `USRP2 Application Notes <./usrp2.html>`_
+* `Daughterboard Application Notes <./dboards.html>`_
+* `Transport Application Notes <./transport.html>`_
 
 ^^^^^^^^^^^^^^^^^^^^^
 API Documentation
diff --git a/host/docs/transport.rst b/host/docs/transport.rst
new file mode 100644
index 000000000..432db4bb5
--- /dev/null
+++ b/host/docs/transport.rst
@@ -0,0 +1,88 @@
+========================================================================
+UHD - Transport Application Notes
+========================================================================
+
+.. contents:: Table of Contents
+
+------------------------------------------------------------------------
+Introduction
+------------------------------------------------------------------------
+A transport is the layer between the packet interface and a device IO interface.
+The advanced user can pass optional parameters
+into the underlying transport layer through the device address.
+These optional parameters control how the transport object allocates memory,
+resizes kernel buffers, spawns threads, etc.
+When not spcified, the transport layer will use values for these parameters
+that are known to perform well on a variety of systems.
+The transport parameters are defined below for the various transports in the UHD:
+
+------------------------------------------------------------------------
+UDP transport (ASIO)
+------------------------------------------------------------------------
+The UDP transport is implemented with Boost's ASIO library.
+ASIO provides an asynchronous API for user-space sockets.
+The transport implementation allocates a number of buffers
+and submits asynchronous requests for send and receive.
+IO service threads run in the background to process these requests.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Transport parameters
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The following parameters can be used to alter the transport's default behavior:
+
+* **recv_frame_size:** The size of a single receive buffer in bytes
+* **num_recv_frames:** The number of receive buffers to allocate
+* **send_frame_size:** The size of a single send buffer in bytes
+* **num_send_frames:** The number of send buffers to allocate
+* **concurrency_hint:** The number of threads to run the IO service
+
+**Note:** num_send_frames and concurrency_hint will not have an effect
+as the asynchronous send implementation is currently disabled.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Resize socket buffers
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+It may be useful increase the size of the socket buffers to
+move the burden of buffering samples into the kernel, or to
+buffer incoming samples faster than they can be processed.
+However, if your application cannot process samples fast enough,
+no amount of buffering can save you.
+The following parameters can be used to alter socket's buffer sizes:
+
+* **recv_buff_size:** The desired size of the receive buffer in bytes
+* **send_buff_size:** The desired size of the send buffer in bytes
+
+**Note:** Large send buffers tend to decrease transmit performance.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Linux specific notes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+On linux, the maximum buffer sizes are capped by the sysctl values
+**net.core.rmem_max** and **net.core.wmem_max**.
+To change the maximum values, run the following commands:
+::
+
+    sudo sysctl -w net.core.rmem_max=<new value>
+    sudo sysctl -w net.core.wmem_max=<new value>
+
+Set the values permanently by editing */etc/sysctl.conf*
+
+------------------------------------------------------------------------
+USB transport (libusb)
+------------------------------------------------------------------------
+The USB transport is implemented with libusb.
+Libusb provides an asynchronous API for USB bulk transfers.
+The transport implementation allocates a number of buffers
+and submits asynchronous requests through libusb.
+Event handler threads run in the background to process these requests.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Transport parameters
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The following parameters can be used to alter the transport's default behavior:
+
+* **recv_frame_size:** The size of a single receive transfers in bytes
+* **num_recv_frames:** The number of simultaneous receive transfers
+* **send_frame_size:** The size of a single send transfers in bytes
+* **num_send_frames:** The number of simultaneous send transfers
+* **concurrency_hint:** The number of threads to run the event handler
diff --git a/host/docs/usrp1.rst b/host/docs/usrp1.rst
index 3c1431d30..3443fd871 100644
--- a/host/docs/usrp1.rst
+++ b/host/docs/usrp1.rst
@@ -100,10 +100,10 @@ OS Specific Notes
 ------------------------------------------------------------------------
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Setup Udev on Linux
+Linux - setup udev
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-On Linux, Udev handles USB plug and unplug events.
-The following command creates a Udev rule for the USRP1
+On Linux, udev handles USB plug and unplug events.
+The following commands create a udev rule for the USRP1
 so that non-root users may access the device:
 
 ::
@@ -113,3 +113,9 @@ so that non-root users may access the device:
     sudo mv tmpfile /etc/udev/rules.d/10-usrp.rules
     sudo udevadm control --reload-rules
 
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Windows - install driver
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+On Windows, a driver must be installed the first time the USRP1 is attached to the host computer.
+A download link for this driver can be found on the UHD wiki page.
+Download and unpack the driver, and direct the Windows driver install wizard to the .inf file.
diff --git a/host/docs/usrp2.rst b/host/docs/usrp2.rst
index 4c95fb24c..0ddcaa4e5 100644
--- a/host/docs/usrp2.rst
+++ b/host/docs/usrp2.rst
@@ -158,7 +158,7 @@ The value for the addr key is a white-space separated list
 of IPv4 addresses or resolvable hostnames.
 The first address in the list will represent channel 0,
 the second channel 1, and so on...
-Use this addressing scheme with the *mimo_usrp* interface.
+Use this addressing scheme with the *multi_usrp* interface.
 
 The device address string representation for 2 USRP2s with IPv4 addresses 192.168.10.2 and 192.168.20.2
 ::
@@ -166,49 +166,22 @@ The device address string representation for 2 USRP2s with IPv4 addresses 192.16
     addr=192.168.10.2 192.168.20.2
 
 ------------------------------------------------------------------------
-Resize the send and receive buffers
+Hardware setup notes
 ------------------------------------------------------------------------
-It may be useful increase the size of the socket buffers to
-move the burden of buffering samples into the kernel, or to
-buffer incoming samples faster than they can be processed.
-However, if you application cannot process samples fast enough,
-no amount of buffering can save you.
-
-By default, the UHD will try to resize both the send and receive buffer for optimum performance.
-A warning will be printed on instantiation if the actual buffer size is insufficient.
-See the OS specific notes below:
-
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-OS specific notes
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-On linux, the maximum buffer sizes are capped by the sysctl values
-**net.core.rmem_max** and **net.core.wmem_max**.
-To change the maximum values, run the following commands:
-::
-
-    sudo sysctl -w net.core.rmem_max=<new value>
-    sudo sysctl -w net.core.wmem_max=<new value>
-
-Set the values permanently by editing */etc/sysctl.conf*
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Device address params
+Front panel LEDs
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-To manually set the size of the buffers,
-the usrp2 will accept two optional parameters in the device address.
-Each parameter will accept a numeric value for the number of bytes.
-
-* recv_buff_size
-* send_buff_size
-
-Example, set the args string to the following:
-::
+The LEDs on the front panel can be useful in debugging hardware and software issues.
+The LEDs reveal the following about the state of the device:
 
-    addr=192.168.10.2, recv_buff_size=100e6
+* **LED A:** transmitting
+* **LED B:** undocumented
+* **LED C:** receiving
+* **LED D:** firmware loaded
+* **LED E:** undocumented
+* **LED F:** FPGA loaded
 
-------------------------------------------------------------------------
-Hardware setup notes
-------------------------------------------------------------------------
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Ref Clock - 10MHz
diff --git a/host/examples/CMakeLists.txt b/host/examples/CMakeLists.txt
index fb7777d42..ce2ca9640 100644
--- a/host/examples/CMakeLists.txt
+++ b/host/examples/CMakeLists.txt
@@ -16,38 +16,35 @@
 #
 
 ########################################################################
-ADD_EXECUTABLE(benchmark_rx_rate benchmark_rx_rate.cpp)
-TARGET_LINK_LIBRARIES(benchmark_rx_rate uhd)
-
-ADD_EXECUTABLE(rx_timed_samples rx_timed_samples.cpp)
-TARGET_LINK_LIBRARIES(rx_timed_samples uhd)
-
-ADD_EXECUTABLE(rx_to_file rx_to_file.cpp)
-TARGET_LINK_LIBRARIES(rx_to_file uhd)
-
-ADD_EXECUTABLE(test_async_messages test_async_messages.cpp)
-TARGET_LINK_LIBRARIES(test_async_messages uhd)
-
-ADD_EXECUTABLE(test_pps_input test_pps_input.cpp)
-TARGET_LINK_LIBRARIES(test_pps_input uhd)
-
-ADD_EXECUTABLE(tx_timed_samples tx_timed_samples.cpp)
-TARGET_LINK_LIBRARIES(tx_timed_samples uhd)
-
-ADD_EXECUTABLE(tx_from_file tx_from_file.cpp)
-TARGET_LINK_LIBRARIES(tx_from_file uhd)
+# example applications
+########################################################################
+SET(example_sources
+    benchmark_rx_rate.cpp
+    rx_samples_to_file.cpp
+    rx_samples_to_udp.cpp
+    rx_timed_samples.cpp
+    test_async_messages.cpp
+    test_pps_input.cpp
+    tx_timed_samples.cpp
+    tx_waveforms.cpp
+)
 
-ADD_EXECUTABLE(tx_waveforms tx_waveforms.cpp)
-TARGET_LINK_LIBRARIES(tx_waveforms uhd)
+#for each source: build an executable and install
+FOREACH(example_source ${example_sources})
+    GET_FILENAME_COMPONENT(example_name ${example_source} NAME_WE)
+    ADD_EXECUTABLE(${example_name} ${example_source})
+    TARGET_LINK_LIBRARIES(${example_name} uhd)
+    INSTALL(TARGETS ${example_name} RUNTIME DESTINATION ${PKG_DATA_DIR}/examples)
+ENDFOREACH(example_source)
 
-INSTALL(TARGETS
-    benchmark_rx_rate
-    rx_timed_samples
-    test_async_messages
-    test_pps_input
-    tx_timed_samples
-    tx_from_file
-    rx_to_file
-    tx_waveforms
-    RUNTIME DESTINATION ${PKG_DATA_DIR}/examples
-)
+########################################################################
+# ASCII Art DFT - requires curses, so this part is optional
+########################################################################
+INCLUDE(FindCurses)
+
+IF(CURSES_FOUND)
+    INCLUDE_DIRECTORIES(${CURSES_INCLUDE_DIR})
+    ADD_EXECUTABLE(rx_ascii_art_dft rx_ascii_art_dft.cpp)
+    TARGET_LINK_LIBRARIES(rx_ascii_art_dft uhd ${CURSES_LIBRARIES})
+    INSTALL(TARGETS rx_ascii_art_dft RUNTIME DESTINATION ${PKG_DATA_DIR}/examples)
+ENDIF(CURSES_FOUND)
diff --git a/host/examples/ascii_art_dft.hpp b/host/examples/ascii_art_dft.hpp
new file mode 100644
index 000000000..ee2267c2d
--- /dev/null
+++ b/host/examples/ascii_art_dft.hpp
@@ -0,0 +1,320 @@
+//
+// ASCII Art DFT Plotter - Josh Blum
+//
+
+#ifndef ASCII_ART_DFT_HPP
+#define ASCII_ART_DFT_HPP
+
+#include <string>
+#include <cstddef>
+#include <vector>
+#include <complex>
+#include <stdexcept>
+
+namespace acsii_art_dft{
+
+    //! Type produced by the log power DFT function
+    typedef std::vector<float> log_pwr_dft_type;
+
+    /*!
+     * Get a logarithmic power DFT of the input samples.
+     * Samples are expected to be in the range [-1.0, 1.0].
+     * \param samps a pointer to an array of complex samples
+     * \param nsamps the number of samples in the array
+     * \return a real range of DFT bins in units of dB
+     */
+    template <typename T> log_pwr_dft_type log_pwr_dft(
+        const std::complex<T> *samps, size_t nsamps
+    );
+
+    /*!
+     * Convert a DFT to a piroundable ascii plot.
+     * \param dft the log power dft bins
+     * \param width the frame width in characters
+     * \param height the frame height in characters
+     * \param samp_rate the sample rate in Sps
+     * \param dc_freq the DC frequency in Hz
+     * \param dyn_rng the dynamic range in dB
+     * \param ref_lvl the reference level in dB
+     * \return the plot as an ascii string
+     */
+    std::string dft_to_plot(
+        const log_pwr_dft_type &dft,
+        size_t width,
+        size_t height,
+        double samp_rate,
+        double dc_freq,
+        float dyn_rng,
+        float ref_lvl
+    );
+
+} //namespace ascii_dft
+
+/***********************************************************************
+ * Implementation includes
+ **********************************************************************/
+#include <cmath>
+#include <sstream>
+#include <algorithm>
+
+/***********************************************************************
+ * Helper functions
+ **********************************************************************/
+namespace {/*anon*/
+
+    static const double pi = double(std::acos(-1.0));
+
+    //! Round a floating-point value to the nearest integer
+    template <typename T> int iround(T val){
+        return (val > 0)? int(val + 0.5) : int(val - 0.5);
+    }
+
+    //! Pick the closest number that is nice to display
+    template <typename T> T to_clean_num(const T num){
+        if (num == 0) return 0;
+        const T pow10 = std::pow(T(10), int(std::floor(std::log10(std::abs(num)))));
+        const T norm = std::abs(num)/pow10;
+        static const int cleans[] = {1, 2, 5, 10};
+        int clean = cleans[0];
+        for (size_t i = 1; i < sizeof(cleans)/sizeof(cleans[0]); i++){
+            if (std::abs(norm - cleans[i]) < std::abs(norm - clean))
+                clean = cleans[i];
+        }
+        return ((num < 0)? -1 : 1)*clean*pow10;
+    }
+
+    //! Compute an FFT with pre-computed factors using Cooley-Tukey
+    template <typename T> std::complex<T> ct_fft_f(
+        const std::complex<T> *samps, size_t nsamps,
+        const std::complex<T> *factors,
+        size_t start = 0, size_t step = 1
+    ){
+        if (nsamps == 1) return samps[start];
+        std::complex<T> E_k = ct_fft_f(samps, nsamps/2, factors+1, start,      step*2);
+        std::complex<T> O_k = ct_fft_f(samps, nsamps/2, factors+1, start+step, step*2);
+        return E_k + factors[0]*O_k;
+    }
+
+    //! Compute an FFT for a particular bin k using Cooley-Tukey
+    template <typename T> std::complex<T> ct_fft_k(
+        const std::complex<T> *samps, size_t nsamps, size_t k
+    ){
+        //pre-compute the factors to use in Cooley-Tukey
+        std::vector<std::complex<T> > factors;
+        for (size_t N = nsamps; N != 0; N /= 2){
+            factors.push_back(std::exp(std::complex<T>(0, T(-2*pi*k/N))));
+        }
+        return ct_fft_f(samps, nsamps, &factors.front());
+    }
+
+    //! Helper class to build a DFT plot frame
+    class frame_type{
+    public:
+        frame_type(size_t width, size_t height):
+            _frame(width-1, std::vector<char>(height, ' '))
+        {
+            /* NOP */
+        }
+
+        //accessors to parts of the frame
+        char &get_plot(size_t b, size_t z){return _frame.at(b+albl_w).at(z+flbl_h);}
+        char &get_albl(size_t b, size_t z){return _frame.at(b)       .at(z+flbl_h);}
+        char &get_ulbl(size_t b)          {return _frame.at(b)       .at(flbl_h-1);}
+        char &get_flbl(size_t b)          {return _frame.at(b+albl_w).at(flbl_h-1);}
+
+        //dimension accessors
+        size_t get_plot_h(void) const{return _frame.front().size() - flbl_h;}
+        size_t get_plot_w(void) const{return _frame.size() - albl_w;}
+        size_t get_albl_w(void) const{return albl_w;}
+
+        std::string to_string(void){
+            std::stringstream frame_ss;
+            for (size_t z = 0; z < _frame.front().size(); z++){
+                for (size_t b = 0; b < _frame.size(); b++){
+                    frame_ss << _frame[b][_frame[b].size()-z-1];
+                }
+                frame_ss << std::endl;
+            }
+            return frame_ss.str();
+        }
+
+    private:
+        static const size_t albl_w = 6, flbl_h = 1;
+        std::vector<std::vector<char> > _frame;
+    };
+
+} //namespace /*anon*/
+
+/***********************************************************************
+ * Implementation code
+ **********************************************************************/
+namespace acsii_art_dft{
+
+    //! skip constants for amplitude and frequency labels
+    static const size_t albl_skip = 5, flbl_skip = 20;
+
+    template <typename T> log_pwr_dft_type log_pwr_dft(
+        const std::complex<T> *samps, size_t nsamps
+    ){
+        if (nsamps & (nsamps - 1))
+            throw std::runtime_error("num samps is not a power of 2");
+
+        //compute the window
+        double win_pwr = 0;
+        std::vector<std::complex<T> > win_samps;
+        for(size_t n = 0; n < nsamps; n++){
+            //double w_n = 1;
+            //double w_n = 0.54 //hamming window
+            //    -0.46*std::cos(2*pi*n/(nsamps-1))
+            //;
+            double w_n = 0.35875 //blackman-harris window
+                -0.48829*std::cos(2*pi*n/(nsamps-1))
+                +0.14128*std::cos(4*pi*n/(nsamps-1))
+                -0.01168*std::cos(6*pi*n/(nsamps-1))
+            ;
+            //double w_n = 1 // flat top window
+            //    -1.930*std::cos(2*pi*n/(nsamps-1))
+            //    +1.290*std::cos(4*pi*n/(nsamps-1))
+            //    -0.388*std::cos(6*pi*n/(nsamps-1))
+            //    +0.032*std::cos(8*pi*n/(nsamps-1))
+            //;
+            win_samps.push_back(T(w_n)*samps[n]);
+            win_pwr += w_n*w_n;
+        }
+
+        //compute the log-power dft
+        log_pwr_dft_type log_pwr_dft;
+        for(size_t k = 0; k < nsamps; k++){
+            std::complex<T> dft_k = ct_fft_k(&win_samps.front(), nsamps, k);
+            log_pwr_dft.push_back(float(
+                + 20*std::log10(std::abs(dft_k))
+                - 20*std::log10(T(nsamps))
+                - 10*std::log10(win_pwr/nsamps)
+                + 3
+            ));
+        }
+
+        return log_pwr_dft;
+    }
+
+    std::string dft_to_plot(
+        const log_pwr_dft_type &dft_,
+        size_t width,
+        size_t height,
+        double samp_rate,
+        double dc_freq,
+        float dyn_rng,
+        float ref_lvl
+    ){
+        frame_type frame(width, height); //fill this frame
+
+        //re-order the dft so dc in in the center
+        const size_t num_bins = dft_.size() - 1 + dft_.size()%2; //make it odd
+        log_pwr_dft_type dft(num_bins);
+        for (size_t n = 0; n < num_bins; n++){
+            dft[n] = dft_[(n + num_bins/2)%num_bins];
+        }
+
+        //fill the plot with dft bins
+        for (size_t b = 0; b < frame.get_plot_w(); b++){
+            //indexes from the dft to grab for the plot
+            const size_t n_start = std::max(iround(double(b-0.5)*(num_bins-1)/(frame.get_plot_w()-1)), 0);
+            const size_t n_stop  = std::min(iround(double(b+0.5)*(num_bins-1)/(frame.get_plot_w()-1)), int(num_bins));
+
+            //calculate val as the max across points
+            float val = dft.at(n_start);
+            for (size_t n = n_start; n < n_stop; n++) val = std::max(val, dft.at(n));
+
+            const float scaled = (val - (ref_lvl - dyn_rng))*(frame.get_plot_h()-1)/dyn_rng;
+            for (size_t z = 0; z < frame.get_plot_h(); z++){
+                static const std::string syms(".:!|");
+                if      (scaled-z > 1) frame.get_plot(b, z) = syms.at(syms.size()-1);
+                else if (scaled-z > 0) frame.get_plot(b, z) = syms.at(size_t((scaled-z)*syms.size()));
+            }
+        }
+
+        //create vertical amplitude labels
+        const float db_step = to_clean_num(dyn_rng/(frame.get_plot_h()-1)*albl_skip);
+        for (
+            float db = db_step*(int((ref_lvl - dyn_rng)/db_step));
+            db      <=  db_step*(int(ref_lvl/db_step));
+            db      +=  db_step
+        ){
+            const int z = iround((db - (ref_lvl - dyn_rng))*(frame.get_plot_h()-1)/dyn_rng);
+            if (z < 0 or size_t(z) >= frame.get_plot_h()) continue;
+            std::stringstream ss; ss << db; std::string lbl = ss.str();
+            for (size_t i = 0; i < lbl.size() and i < frame.get_albl_w(); i++){
+                frame.get_albl(i, z) = lbl[i];
+            }
+        }
+
+        //create vertical units label
+        std::string ulbl = "dBfs";
+        for (size_t i = 0; i < ulbl.size(); i++){
+            frame.get_ulbl(i+1) = ulbl[i];
+        }
+
+        //create horizontal frequency labels
+        const double f_step = to_clean_num(samp_rate/frame.get_plot_w()*flbl_skip);
+        for (
+            double freq = f_step*int((-samp_rate/2/f_step));
+            freq       <= f_step*int((+samp_rate/2/f_step));
+            freq       += f_step
+        ){
+            const int b = iround((freq + samp_rate/2)*(frame.get_plot_w()-1)/samp_rate);
+            std::stringstream ss; ss << (freq+dc_freq)/1e6 << "MHz"; std::string lbl = ss.str();
+            if (b < int(lbl.size()/2) or b + lbl.size() - lbl.size()/2 >= frame.get_plot_w()) continue;
+            for (size_t i = 0; i < lbl.size(); i++){
+                frame.get_flbl(b + i - lbl.size()/2) = lbl[i];
+            }
+        }
+
+        return frame.to_string();
+    }
+} //namespace ascii_dft
+
+#endif /*ASCII_ART_DFT_HPP*/
+
+/*
+
+//example main function to test the dft
+
+#include <iostream>
+#include <cstdlib>
+#include <curses.h>
+
+int main(void){
+    initscr();
+
+    while (true){
+        clear();
+
+        std::vector<std::complex<float> > samples;
+        for(size_t i = 0; i < 512; i++){
+            samples.push_back(std::complex<float>(
+                float(std::rand() - RAND_MAX/2)/(RAND_MAX)/4,
+                float(std::rand() - RAND_MAX/2)/(RAND_MAX)/4
+            ));
+            samples[i] += 0.5*std::sin(i*3.14/2) + 0.7;
+        }
+
+        acsii_art_dft::log_pwr_dft_type dft;
+        dft = acsii_art_dft::log_pwr_dft(&samples.front(), samples.size());
+
+        printw("%s", acsii_art_dft::dft_to_plot(
+            dft, COLS, LINES,
+            12.5e4, 2.45e9,
+            60, 0
+        ).c_str());
+
+        sleep(1);
+    }
+
+
+    endwin();
+    std::cout << "here\n";
+    return 0;
+}
+
+*/
+
diff --git a/host/examples/benchmark_rx_rate.cpp b/host/examples/benchmark_rx_rate.cpp
index 36611f97f..b189368f9 100644
--- a/host/examples/benchmark_rx_rate.cpp
+++ b/host/examples/benchmark_rx_rate.cpp
@@ -137,7 +137,6 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
     uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
     std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
-    sdev->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS); //stop if left running
 
     if (not vm.count("rate")){
         sdev->set_rx_rate(500e3); //initial rate
diff --git a/host/examples/rx_ascii_art_dft.cpp b/host/examples/rx_ascii_art_dft.cpp
new file mode 100644
index 000000000..5a24867b4
--- /dev/null
+++ b/host/examples/rx_ascii_art_dft.cpp
@@ -0,0 +1,143 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/utils/thread_priority.hpp>
+#include <uhd/utils/safe_main.hpp>
+#include <uhd/usrp/single_usrp.hpp>
+#include "ascii_art_dft.hpp" //implementation
+#include <boost/program_options.hpp>
+#include <boost/thread.hpp> //gets time
+#include <boost/format.hpp>
+#include <curses.h>
+#include <iostream>
+#include <complex>
+
+namespace po = boost::program_options;
+
+int UHD_SAFE_MAIN(int argc, char *argv[]){
+    uhd::set_thread_priority_safe();
+
+    //variables to be set by po
+    std::string args;
+    size_t num_bins;
+    double rate, freq, frame_rate;
+    float gain, ref_lvl, dyn_rng;
+
+    //setup the program options
+    po::options_description desc("Allowed options");
+    desc.add_options()
+        ("help", "help message")
+        ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
+        // hardware parameters
+        ("rate", po::value<double>(&rate), "rate of incoming samples (sps)")
+        ("freq", po::value<double>(&freq)->default_value(0), "RF center frequency in Hz")
+        ("gain", po::value<float>(&gain)->default_value(0), "gain for the RF chain")
+        // display parameters
+        ("num-bins", po::value<size_t>(&num_bins)->default_value(512), "the number of bins in the DFT")
+        ("frame-rate", po::value<double>(&frame_rate)->default_value(5), "frame rate of the display (fps)")
+        ("ref-lvl", po::value<float>(&ref_lvl)->default_value(0), "reference level for the display (dB)")
+        ("dyn-rng", po::value<float>(&dyn_rng)->default_value(60), "dynamic range for the display (dB)")
+    ;
+    po::variables_map vm;
+    po::store(po::parse_command_line(argc, argv, desc), vm);
+    po::notify(vm);
+
+    //print the help message
+    if (vm.count("help") or not vm.count("rate")){
+        std::cout << boost::format("UHD RX ASCII Art DFT %s") % desc << std::endl;
+        return ~0;
+    }
+
+    //create a usrp device
+    std::cout << std::endl;
+    std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
+    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+
+    //set the rx sample rate
+    std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate/1e6) << std::endl;
+    sdev->set_rx_rate(rate);
+    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl << std::endl;
+
+    //set the rx center frequency
+    std::cout << boost::format("Setting RX Freq: %f Mhz...") % (freq/1e6) << std::endl;
+    sdev->set_rx_freq(freq);
+    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (sdev->get_rx_freq()/1e6) << std::endl << std::endl;
+
+    //set the rx rf gain
+    std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
+    sdev->set_rx_gain(gain);
+    std::cout << boost::format("Actual RX Gain: %f dB...") % sdev->get_rx_gain() << std::endl << std::endl;
+
+    //allocate recv buffer and metatdata
+    uhd::rx_metadata_t md;
+    std::vector<std::complex<float> > buff(num_bins);
+    //------------------------------------------------------------------
+    //-- Initialize
+    //------------------------------------------------------------------
+    initscr(); //curses init
+    sdev->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
+    boost::system_time next_refresh = boost::get_system_time();
+
+    //------------------------------------------------------------------
+    //-- Main loop
+    //------------------------------------------------------------------
+    while (true){
+        //read a buffer's worth of samples every iteration
+        size_t num_rx_samps = sdev->get_device()->recv(
+            &buff.front(), buff.size(), md,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_FULL_BUFF
+        );
+        if (num_rx_samps != buff.size()) continue;
+
+        //check and update the display refresh condition
+        if (boost::get_system_time() < next_refresh) continue;
+        next_refresh = boost::get_system_time() + boost::posix_time::microseconds(long(1e6/frame_rate));
+
+        //calculate the dft and create the ascii art frame
+        acsii_art_dft::log_pwr_dft_type lpdft(
+            acsii_art_dft::log_pwr_dft(&buff.front(), num_rx_samps)
+        );
+        std::string frame = acsii_art_dft::dft_to_plot(
+            lpdft, COLS, LINES,
+            sdev->get_rx_rate(),
+            sdev->get_rx_freq(),
+            dyn_rng, ref_lvl
+        );
+
+        //curses screen handling: clear and print frame
+        clear();
+        printw("%s", frame.c_str());
+
+        //curses key handling: no timeout, any key to exit
+        timeout(0);
+        int ch = getch();
+        if (ch != KEY_RESIZE and ch != ERR) break;
+    }
+
+    //------------------------------------------------------------------
+    //-- Cleanup
+    //------------------------------------------------------------------
+    sdev->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);
+    endwin(); //curses done
+
+    //finished
+    std::cout << std::endl << "Done!" << std::endl << std::endl;
+
+    return 0;
+}
diff --git a/host/examples/rx_to_file.cpp b/host/examples/rx_samples_to_file.cpp
index 79d3e9d8b..c80d2a6de 100644
--- a/host/examples/rx_to_file.cpp
+++ b/host/examples/rx_samples_to_file.cpp
@@ -17,35 +17,35 @@
 
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/safe_main.hpp>
-#include <uhd/usrp/simple_usrp.hpp>
+#include <uhd/usrp/single_usrp.hpp>
 #include <boost/program_options.hpp>
 #include <boost/format.hpp>
+#include <boost/thread.hpp>
 #include <iostream>
 #include <fstream>
 #include <complex>
 
 namespace po = boost::program_options;
 
-
 int UHD_SAFE_MAIN(int argc, char *argv[]){
     uhd::set_thread_priority_safe();
 
     //variables to be set by po
-    std::string args;
-    time_t seconds_in_future;
+    std::string args, file;
     size_t total_num_samps;
-    double rx_rate, freq;
+    double rate, freq;
+    float gain;
 
     //setup the program options
     po::options_description desc("Allowed options");
     desc.add_options()
         ("help", "help message")
-        ("args", po::value<std::string>(&args)->default_value(""), "simple uhd device address args")
-        ("secs", po::value<time_t>(&seconds_in_future)->default_value(3), "number of seconds in the future to receive")
+        ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
+        ("file", po::value<std::string>(&file)->default_value("out.16sc.dat"), "name of the file to write binary samples to")
         ("nsamps", po::value<size_t>(&total_num_samps)->default_value(1000), "total number of samples to receive")
-        ("rxrate", po::value<double>(&rx_rate)->default_value(100e6/16), "rate of incoming samples")
+        ("rate", po::value<double>(&rate)->default_value(100e6/16), "rate of incoming samples")
         ("freq", po::value<double>(&freq)->default_value(0), "rf center frequency in Hz")
-        ("dilv", "specify to disable inner-loop verbose")
+        ("gain", po::value<float>(&gain)->default_value(0), "gain for the RF chain")
     ;
     po::variables_map vm;
     po::store(po::parse_command_line(argc, argv, desc), vm);
@@ -53,50 +53,46 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
 
     //print the help message
     if (vm.count("help")){
-        std::cout << boost::format("UHD RX Timed Samples %s") % desc << std::endl;
+        std::cout << boost::format("UHD RX to File %s") % desc << std::endl;
         return ~0;
     }
 
-    bool verbose = vm.count("dilv") == 0;
-
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::simple_usrp::sptr sdev = uhd::usrp::simple_usrp::make(args);
+    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
     uhd::device::sptr dev = sdev->get_device();
     std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
 
-    //set properties on the device
-    std::cout << boost::format("Setting RX Rate: %f Msps...") % (rx_rate/1e6) << std::endl;
-    sdev->set_rx_rate(rx_rate);
-    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl;
-    std::cout << boost::format("Setting device timestamp to 0...") << std::endl;
+    //set the rx sample rate
+    std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate/1e6) << std::endl;
+    sdev->set_rx_rate(rate);
+    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl << std::endl;
+
+    //set the rx center frequency
+    std::cout << boost::format("Setting RX Freq: %f Mhz...") % (freq/1e6) << std::endl;
     sdev->set_rx_freq(freq);
-    sdev->set_time_now(uhd::time_spec_t(0.0));
+    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (sdev->get_rx_freq()/1e6) << std::endl << std::endl;
 
-    uhd::gain_range_t rx_gain = sdev->get_rx_gain_range();
-    std::cout << "Setting RX Gain to: " << rx_gain.max << std::endl;
-    sdev->set_rx_gain(rx_gain.max);
+    //set the rx rf gain
+    std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
+    sdev->set_rx_gain(gain);
+    std::cout << boost::format("Actual RX Gain: %f dB...") % sdev->get_rx_gain() << std::endl << std::endl;
 
-    sleep(1);
+    boost::this_thread::sleep(boost::posix_time::seconds(1)); //allow for some setup time
     std::cout << "LO Locked = " << sdev->get_rx_lo_locked() << std::endl;
 
     //setup streaming
-    std::cout << std::endl;
-    std::cout << boost::format(
-        "Begin streaming %u samples, %d seconds in the future..."
-    ) % total_num_samps % seconds_in_future << std::endl;
     uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
     stream_cmd.num_samps = total_num_samps;
-    stream_cmd.stream_now = false;
-    stream_cmd.time_spec = uhd::time_spec_t(seconds_in_future);
+    stream_cmd.stream_now = true;
     sdev->issue_stream_cmd(stream_cmd);
 
     //loop until total number of samples reached
     size_t num_acc_samps = 0; //number of accumulated samples
     uhd::rx_metadata_t md;
     std::vector<std::complex<short> > buff(dev->get_max_recv_samps_per_packet());
-    std::ofstream outfile("out.dat", std::ofstream::binary);
+    std::ofstream outfile(file.c_str(), std::ofstream::binary);
 
     while(num_acc_samps < total_num_samps){
         size_t num_rx_samps = dev->recv(
@@ -124,11 +120,8 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
             goto done_loop;
         }
 
-	outfile.write((const char*)&buff[0], num_rx_samps * sizeof(std::complex<short>));
-
-        if(verbose) std::cout << boost::format(
-            "Got packet: %u samples, %u full secs, %f frac secs"
-        ) % num_rx_samps % md.time_spec.get_full_secs() % md.time_spec.get_frac_secs() << std::endl;
+        //write complex short integer samples to the binary file
+        outfile.write((const char*)&buff[0], num_rx_samps * sizeof(std::complex<short>));
 
         num_acc_samps += num_rx_samps;
     } done_loop:
diff --git a/host/examples/rx_samples_to_udp.cpp b/host/examples/rx_samples_to_udp.cpp
new file mode 100644
index 000000000..488c95494
--- /dev/null
+++ b/host/examples/rx_samples_to_udp.cpp
@@ -0,0 +1,135 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/utils/thread_priority.hpp>
+#include <uhd/utils/safe_main.hpp>
+#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/transport/udp_simple.hpp>
+#include <boost/program_options.hpp>
+#include <boost/format.hpp>
+#include <boost/thread.hpp>
+#include <iostream>
+#include <complex>
+
+namespace po = boost::program_options;
+
+int UHD_SAFE_MAIN(int argc, char *argv[]){
+    uhd::set_thread_priority_safe();
+
+    //variables to be set by po
+    std::string args;
+    size_t total_num_samps;
+    double rate, freq;
+    float gain;
+    std::string addr, port;
+
+    //setup the program options
+    po::options_description desc("Allowed options");
+    desc.add_options()
+        ("help", "help message")
+        ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
+        ("nsamps", po::value<size_t>(&total_num_samps)->default_value(1000), "total number of samples to receive")
+        ("rate", po::value<double>(&rate)->default_value(100e6/16), "rate of incoming samples")
+        ("freq", po::value<double>(&freq)->default_value(0), "rf center frequency in Hz")
+        ("gain", po::value<float>(&gain)->default_value(0), "gain for the RF chain")
+        ("port", po::value<std::string>(&port)->default_value("7124"), "server udp port")
+        ("addr", po::value<std::string>(&addr)->default_value("192.168.1.10"), "resolvable server address")
+    ;
+    po::variables_map vm;
+    po::store(po::parse_command_line(argc, argv, desc), vm);
+    po::notify(vm);
+
+    //print the help message
+    if (vm.count("help")){
+        std::cout << boost::format("UHD RX to UDP %s") % desc << std::endl;
+        return ~0;
+    }
+
+    //create a usrp device
+    std::cout << std::endl;
+    std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
+    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
+    uhd::device::sptr dev = sdev->get_device();
+    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+
+    //set the rx sample rate
+    std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate/1e6) << std::endl;
+    sdev->set_rx_rate(rate);
+    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl << std::endl;
+
+    //set the rx center frequency
+    std::cout << boost::format("Setting RX Freq: %f Mhz...") % (freq/1e6) << std::endl;
+    sdev->set_rx_freq(freq);
+    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (sdev->get_rx_freq()/1e6) << std::endl << std::endl;
+
+    //set the rx rf gain
+    std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
+    sdev->set_rx_gain(gain);
+    std::cout << boost::format("Actual RX Gain: %f dB...") % sdev->get_rx_gain() << std::endl << std::endl;
+
+    boost::this_thread::sleep(boost::posix_time::seconds(1)); //allow for some setup time
+    std::cout << "LO Locked = " << sdev->get_rx_lo_locked() << std::endl;
+
+    //setup streaming
+    uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
+    stream_cmd.num_samps = total_num_samps;
+    stream_cmd.stream_now = true;
+    sdev->issue_stream_cmd(stream_cmd);
+
+    //loop until total number of samples reached
+    size_t num_acc_samps = 0; //number of accumulated samples
+    uhd::rx_metadata_t md;
+    std::vector<std::complex<float> > buff(dev->get_max_recv_samps_per_packet());
+    uhd::transport::udp_simple::sptr udp_xport = uhd::transport::udp_simple::make_connected(addr, port);
+
+    while(num_acc_samps < total_num_samps){
+        size_t num_rx_samps = dev->recv(
+            &buff.front(), buff.size(), md,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET
+        );
+
+        //handle the error codes
+        switch(md.error_code){
+        case uhd::rx_metadata_t::ERROR_CODE_NONE:
+            break;
+
+        case uhd::rx_metadata_t::ERROR_CODE_TIMEOUT:
+            if (num_acc_samps == 0) continue;
+            std::cout << boost::format(
+                "Got timeout before all samples received, possible packet loss, exiting loop..."
+            ) << std::endl;
+            goto done_loop;
+
+        default:
+            std::cout << boost::format(
+                "Got error code 0x%x, exiting loop..."
+            ) % md.error_code << std::endl;
+            goto done_loop;
+        }
+
+        //send complex single precision floating point samples over udp
+        udp_xport->send(boost::asio::buffer(buff, num_rx_samps));
+
+        num_acc_samps += num_rx_samps;
+    } done_loop:
+
+    //finished
+    std::cout << std::endl << "Done!" << std::endl << std::endl;
+
+    return 0;
+}
diff --git a/host/examples/rx_timed_samples.cpp b/host/examples/rx_timed_samples.cpp
index 441665900..8a810811f 100644
--- a/host/examples/rx_timed_samples.cpp
+++ b/host/examples/rx_timed_samples.cpp
@@ -32,7 +32,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     std::string args;
     time_t seconds_in_future;
     size_t total_num_samps;
-    double rx_rate, freq;
+    double rate, freq;
 
     //setup the program options
     po::options_description desc("Allowed options");
@@ -41,7 +41,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
         ("secs", po::value<time_t>(&seconds_in_future)->default_value(3), "number of seconds in the future to receive")
         ("nsamps", po::value<size_t>(&total_num_samps)->default_value(1000), "total number of samples to receive")
-        ("rxrate", po::value<double>(&rx_rate)->default_value(100e6/16), "rate of incoming samples")
+        ("rate", po::value<double>(&rate)->default_value(100e6/16), "rate of incoming samples")
         ("freq", po::value<double>(&freq)->default_value(0), "rf center frequency in Hz")
         ("dilv", "specify to disable inner-loop verbose")
     ;
@@ -64,12 +64,17 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     uhd::device::sptr dev = sdev->get_device();
     std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
 
-    //set properties on the device
-    std::cout << boost::format("Setting RX Rate: %f Msps...") % (rx_rate/1e6) << std::endl;
-    sdev->set_rx_rate(rx_rate);
-    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl;
-    std::cout << boost::format("Setting device timestamp to 0...") << std::endl;
+    //set the rx sample rate
+    std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate/1e6) << std::endl;
+    sdev->set_rx_rate(rate);
+    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl << std::endl;
+
+    //set the rx center frequency
+    std::cout << boost::format("Setting RX Freq: %f Mhz...") % (freq/1e6) << std::endl;
     sdev->set_rx_freq(freq);
+    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (sdev->get_rx_freq()/1e6) << std::endl << std::endl;
+
+    std::cout << boost::format("Setting device timestamp to 0...") << std::endl;
     sdev->set_time_now(uhd::time_spec_t(0.0));
 
     //setup streaming
diff --git a/host/examples/test_async_messages.cpp b/host/examples/test_async_messages.cpp
index 4c9d18121..e4a996ef5 100644
--- a/host/examples/test_async_messages.cpp
+++ b/host/examples/test_async_messages.cpp
@@ -26,8 +26,6 @@
 
 namespace po = boost::program_options;
 
-static const size_t async_to_ms = 100;
-
 /*!
  * Test that no messages are received:
  *    Send a burst of many samples that will fragment internally.
@@ -52,13 +50,13 @@ void test_no_async_message(uhd::usrp::single_usrp::sptr sdev){
     );
 
     uhd::async_metadata_t async_md;
-    if (dev->recv_async_msg(async_md, async_to_ms)){
+    if (dev->recv_async_msg(async_md)){
         std::cout << boost::format(
             "failed:\n"
             "    Got unexpected event code 0x%x.\n"
         ) % async_md.event_code << std::endl;
         //clear the async messages
-        while (dev->recv_async_msg(async_md, 0));
+        while (dev->recv_async_msg(async_md, 0)){};
     }
     else{
         std::cout << boost::format(
@@ -88,7 +86,7 @@ void test_underflow_message(uhd::usrp::single_usrp::sptr sdev){
     );
 
     uhd::async_metadata_t async_md;
-    if (not dev->recv_async_msg(async_md, async_to_ms)){
+    if (not dev->recv_async_msg(async_md)){
         std::cout << boost::format(
             "failed:\n"
             "    Async message recv timed out.\n"
@@ -135,7 +133,7 @@ void test_time_error_message(uhd::usrp::single_usrp::sptr sdev){
     );
 
     uhd::async_metadata_t async_md;
-    if (not dev->recv_async_msg(async_md, async_to_ms)){
+    if (not dev->recv_async_msg(async_md)){
         std::cout << boost::format(
             "failed:\n"
             "    Async message recv timed out.\n"
diff --git a/host/examples/tx_timed_samples.cpp b/host/examples/tx_timed_samples.cpp
index f34c121d5..799da37e0 100644
--- a/host/examples/tx_timed_samples.cpp
+++ b/host/examples/tx_timed_samples.cpp
@@ -33,7 +33,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     time_t seconds_in_future;
     size_t total_num_samps;
     size_t samps_per_packet;
-    double tx_rate, freq;
+    double rate, freq;
     float ampl;
 
     //setup the program options
@@ -44,7 +44,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         ("secs", po::value<time_t>(&seconds_in_future)->default_value(3), "number of seconds in the future to transmit")
         ("nsamps", po::value<size_t>(&total_num_samps)->default_value(1000), "total number of samples to transmit")
         ("spp", po::value<size_t>(&samps_per_packet)->default_value(1000), "number of samples per packet")
-        ("txrate", po::value<double>(&tx_rate)->default_value(100e6/16), "rate of outgoing samples")
+        ("rate", po::value<double>(&rate)->default_value(100e6/16), "rate of outgoing samples")
         ("freq", po::value<double>(&freq)->default_value(0), "rf center frequency in Hz")
         ("ampl", po::value<float>(&ampl)->default_value(float(0.3)), "amplitude of each sample")
         ("dilv", "specify to disable inner-loop verbose")
@@ -68,12 +68,17 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     uhd::device::sptr dev = sdev->get_device();
     std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
 
-    //set properties on the device
-    std::cout << boost::format("Setting TX Rate: %f Msps...") % (tx_rate/1e6) << std::endl;
-    sdev->set_tx_rate(tx_rate);
-    std::cout << boost::format("Actual TX Rate: %f Msps...") % (sdev->get_tx_rate()/1e6) << std::endl;
-    std::cout << boost::format("Setting device timestamp to 0...") << std::endl;
+    //set the tx sample rate
+    std::cout << boost::format("Setting TX Rate: %f Msps...") % (rate/1e6) << std::endl;
+    sdev->set_tx_rate(rate);
+    std::cout << boost::format("Actual TX Rate: %f Msps...") % (sdev->get_tx_rate()/1e6) << std::endl << std::endl;
+
+    //set the tx center frequency
+    std::cout << boost::format("Setting TX Freq: %f Mhz...") % (freq/1e6) << std::endl;
     sdev->set_tx_freq(freq);
+    std::cout << boost::format("Actual TX Freq: %f Mhz...") % (sdev->get_tx_freq()/1e6) << std::endl << std::endl;
+
+    std::cout << boost::format("Setting device timestamp to 0...") << std::endl;
     sdev->set_time_now(uhd::time_spec_t(0.0));
 
     //allocate data to send
@@ -95,8 +100,11 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         size_t num_tx_samps = dev->send(
             &buff.front(), samps_to_send, md,
             uhd::io_type_t::COMPLEX_FLOAT32,
-            uhd::device::SEND_MODE_FULL_BUFF
+            uhd::device::SEND_MODE_FULL_BUFF,
+            //send will backup into the host this many seconds before sending:
+            seconds_in_future + 0.1 //timeout (delay before transmit + padding)
         );
+        if (num_tx_samps < samps_to_send) std::cout << "Send timeout..." << std::endl;
         if(verbose) std::cout << std::endl << boost::format("Sent %d samples") % num_tx_samps << std::endl;
     }
 
diff --git a/host/include/linux/usrp_e.h b/host/include/linux/usrp_e.h
index 80f3a287b..4c6a5dd89 100644
--- a/host/include/linux/usrp_e.h
+++ b/host/include/linux/usrp_e.h
@@ -65,12 +65,16 @@ struct usrp_e_i2c {
 #define USRP_E_I2C_READ		_IOWR(USRP_E_IOC_MAGIC, 0x25, struct usrp_e_i2c)
 #define USRP_E_I2C_WRITE	_IOW(USRP_E_IOC_MAGIC, 0x26, struct usrp_e_i2c)
 #define USRP_E_GET_RB_INFO      _IOR(USRP_E_IOC_MAGIC, 0x27, struct usrp_e_ring_buffer_size_t)
+#define USRP_E_GET_COMPAT_NUMBER _IO(USRP_E_IOC_MAGIC, 0x28)
+
+#define USRP_E_COMPAT_NUMBER 1
 
 /* Flag defines */
 #define RB_USER (1<<0)
 #define RB_KERNEL (1<<1)
 #define RB_OVERRUN (1<<2)
 #define RB_DMA_ACTIVE (1<<3)
+#define RB_USER_PROCESS (1<<4)
 
 struct ring_buffer_info {
 	int flags;
diff --git a/host/include/uhd/config.hpp b/host/include/uhd/config.hpp
index dacd3a96b..2918c2340 100644
--- a/host/include/uhd/config.hpp
+++ b/host/include/uhd/config.hpp
@@ -31,11 +31,12 @@
 # pragma warning(disable: 4251) // class 'A<T>' needs to have dll-interface to be used by clients of class 'B'
 //# pragma warning(disable: 4127) // conditional expression is constant
 //# pragma warning(disable: 4290) // C++ exception specification ignored except to ...
-# pragma warning(disable: 4180) // qualifier applied to function type has no meaning; ignored
+//# pragma warning(disable: 4180) // qualifier applied to function type has no meaning; ignored
 # pragma warning(disable: 4275) // non dll-interface class ... used as base for dll-interface class ...
 //# pragma warning(disable: 4267) // 'var' : conversion from 'size_t' to 'type', possible loss of data
 //# pragma warning(disable: 4511) // 'class' : copy constructor could not be generated
-# pragma warning(disable: 4250) // 'class' : inherits 'method' via dominance
+//# pragma warning(disable: 4250) // 'class' : inherits 'method' via dominance
+# pragma warning(disable: 4200) // nonstandard extension used : zero-sized array in struct/union
 #endif
 
 // define logical operators
diff --git a/host/include/uhd/device.hpp b/host/include/uhd/device.hpp
index 2077cae62..992276928 100644
--- a/host/include/uhd/device.hpp
+++ b/host/include/uhd/device.hpp
@@ -41,9 +41,6 @@ public:
     typedef boost::function<device_addrs_t(const device_addr_t &)> find_t;
     typedef boost::function<sptr(const device_addr_t &)> make_t;
 
-    //! A reasonable default timeout for receive
-    static const size_t default_recv_timeout_ms = 100;
-
     /*!
      * Register a device into the discovery and factory system.
      *
@@ -112,12 +109,15 @@ public:
      *
      * This is a blocking call and will not return until the number
      * of samples returned have been read out of each buffer.
+     * Under a timeout condition, the number of samples returned
+     * may be less than the number of samples specified.
      *
      * \param buffs a vector of read-only memory containing IF data
      * \param nsamps_per_buff the number of samples to send, per buffer
      * \param metadata data describing the buffer's contents
      * \param io_type the type of data loaded in the buffer
      * \param send_mode tells send how to unload the buffer
+     * \param timeout the timeout in seconds to wait on a packet
      * \return the number of samples sent
      */
     virtual size_t send(
@@ -125,7 +125,8 @@ public:
         size_t nsamps_per_buff,
         const tx_metadata_t &metadata,
         const io_type_t &io_type,
-        send_mode_t send_mode
+        send_mode_t send_mode,
+        double timeout = 0.1
     ) = 0;
 
     /*!
@@ -136,7 +137,8 @@ public:
         size_t nsamps_per_buff,
         const tx_metadata_t &metadata,
         const io_type_t &io_type,
-        send_mode_t send_mode
+        send_mode_t send_mode,
+        double timeout = 0.1
     );
 
     /*!
@@ -154,7 +156,9 @@ public:
      * See the rx metadata fragment flags and offset fields for details.
      *
      * This is a blocking call and will not return until the number
-     * of samples returned have been written into each buffer or timeout.
+     * of samples returned have been written into each buffer.
+     * Under a timeout condition, the number of samples returned
+     * may be less than the number of samples specified.
      *
      * When using the full buffer recv mode, the metadata only applies
      * to the first packet received and written into the recv buffers.
@@ -165,7 +169,7 @@ public:
      * \param metadata data to fill describing the buffer
      * \param io_type the type of data to fill into the buffer
      * \param recv_mode tells recv how to load the buffer
-     * \param timeout_ms the timeout in milliseconds to wait for a packet
+     * \param timeout the timeout in seconds to wait for a packet
      * \return the number of samples received or 0 on error
      */
     virtual size_t recv(
@@ -174,7 +178,7 @@ public:
         rx_metadata_t &metadata,
         const io_type_t &io_type,
         recv_mode_t recv_mode,
-        size_t timeout_ms = default_recv_timeout_ms
+        double timeout = 0.1
     ) = 0;
 
     /*!
@@ -186,7 +190,7 @@ public:
         rx_metadata_t &metadata,
         const io_type_t &io_type,
         recv_mode_t recv_mode,
-        size_t timeout_ms = default_recv_timeout_ms
+        double timeout = 0.1
     );
 
     /*!
@@ -204,12 +208,11 @@ public:
     /*!
      * Receive and asynchronous message from the device.
      * \param async_metadata the metadata to be filled in
-     * \param timeout_ms the timeout in milliseconds to wait for a message
+     * \param timeout the timeout in seconds to wait for a message
      * \return true when the async_metadata is valid, false for timeout
      */
     virtual bool recv_async_msg(
-        async_metadata_t &async_metadata,
-        size_t timeout_ms = default_recv_timeout_ms
+        async_metadata_t &async_metadata, double timeout = 0.1
     ) = 0;
 
 };
diff --git a/host/include/uhd/device.ipp b/host/include/uhd/device.ipp
index 60a3f535d..e2e51ecd0 100644
--- a/host/include/uhd/device.ipp
+++ b/host/include/uhd/device.ipp
@@ -25,12 +25,13 @@ namespace uhd{
         size_t nsamps_per_buff,
         const tx_metadata_t &metadata,
         const io_type_t &io_type,
-        send_mode_t send_mode
+        send_mode_t send_mode,
+        double timeout
     ){
         return this->send(
             std::vector<const void *>(1, buff),
             nsamps_per_buff, metadata,
-            io_type, send_mode
+            io_type, send_mode, timeout
         );
     }
 
@@ -40,12 +41,12 @@ namespace uhd{
         rx_metadata_t &metadata,
         const io_type_t &io_type,
         recv_mode_t recv_mode,
-        size_t timeout_ms
+        double timeout
     ){
         return this->recv(
             std::vector<void *>(1, buff),
             nsamps_per_buff, metadata,
-            io_type, recv_mode, timeout_ms
+            io_type, recv_mode, timeout
         );
     }
 
diff --git a/host/include/uhd/transport/alignment_buffer.hpp b/host/include/uhd/transport/alignment_buffer.hpp
index 29ba74efc..f44a037f8 100644
--- a/host/include/uhd/transport/alignment_buffer.hpp
+++ b/host/include/uhd/transport/alignment_buffer.hpp
@@ -48,20 +48,17 @@ namespace uhd{ namespace transport{
          * \return true if the element fit without popping for space
          */
         virtual bool push_with_pop_on_full(
-            const elem_type &elem,
-            const seq_type &seq,
-            size_t index
+            const elem_type &elem, const seq_type &seq, size_t index
         ) = 0;
 
         /*!
          * Pop an aligned set of elements from this alignment buffer.
          * \param elems a collection to store the aligned elements
-         * \param time the timeout time
+         * \param timeout the timeout in seconds
          * \return false when the operation times out
          */
         virtual bool pop_elems_with_timed_wait(
-            std::vector<elem_type> &elems,
-            const time_duration_t &time
+            std::vector<elem_type> &elems, double timeout
         ) = 0;
     };
 
diff --git a/host/include/uhd/transport/alignment_buffer.ipp b/host/include/uhd/transport/alignment_buffer.ipp
index 61b3b60f5..833b5d399 100644
--- a/host/include/uhd/transport/alignment_buffer.ipp
+++ b/host/include/uhd/transport/alignment_buffer.ipp
@@ -41,9 +41,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
         }
 
         UHD_INLINE bool push_with_pop_on_full(
-            const elem_type &elem,
-            const seq_type &seq,
-            size_t index
+            const elem_type &elem, const seq_type &seq, size_t index
         ){
             //clear the buffer for this index if the seqs are mis-ordered
             if (seq < _last_seqs[index]){
@@ -54,17 +52,16 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
         }
 
         UHD_INLINE bool pop_elems_with_timed_wait(
-            std::vector<elem_type> &elems,
-            const time_duration_t &time
+            std::vector<elem_type> &elems, double timeout
         ){
-            boost::system_time exit_time = boost::get_system_time() + time;
+            boost::system_time exit_time = boost::get_system_time() + to_time_dur(timeout);
             buff_contents_type buff_contents_tmp;
             std::list<size_t> indexes_to_do(_all_indexes);
 
             //do an initial pop to load an initial sequence id
             size_t index = indexes_to_do.front();
             if (not _buffs[index]->pop_with_timed_wait(
-                buff_contents_tmp, exit_time - boost::get_system_time()
+                buff_contents_tmp, from_time_dur(exit_time - boost::get_system_time())
             )) return false;
             elems[index] = buff_contents_tmp.first;
             seq_type expected_seq_id = buff_contents_tmp.second;
@@ -79,7 +76,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
                     indexes_to_do = _all_indexes;
                     index = indexes_to_do.front();
                     if (not _buffs[index]->pop_with_timed_wait(
-                        buff_contents_tmp, exit_time - boost::get_system_time()
+                        buff_contents_tmp, from_time_dur(exit_time - boost::get_system_time())
                     )) return false;
                     elems[index] = buff_contents_tmp.first;
                     expected_seq_id = buff_contents_tmp.second;
@@ -89,7 +86,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
                 //pop an element off for this index
                 index = indexes_to_do.front();
                 if (not _buffs[index]->pop_with_timed_wait(
-                    buff_contents_tmp, exit_time - boost::get_system_time()
+                    buff_contents_tmp, from_time_dur(exit_time - boost::get_system_time())
                 )) return false;
 
                 //if the sequence id matches:
diff --git a/host/include/uhd/transport/bounded_buffer.hpp b/host/include/uhd/transport/bounded_buffer.hpp
index d1deece96..aca93b071 100644
--- a/host/include/uhd/transport/bounded_buffer.hpp
+++ b/host/include/uhd/transport/bounded_buffer.hpp
@@ -20,13 +20,9 @@
 
 #include <uhd/config.hpp>
 #include <boost/shared_ptr.hpp>
-#include <boost/date_time/posix_time/posix_time_types.hpp>
 
 namespace uhd{ namespace transport{
 
-    //! typedef for the time duration type for wait operations
-    typedef boost::posix_time::time_duration time_duration_t;
-
     /*!
      * Implement a templated bounded buffer:
      * Used for passing elements between threads in a producer-consumer model.
@@ -64,10 +60,10 @@ namespace uhd{ namespace transport{
          * Push a new element into the bounded_buffer.
          * Wait until the bounded_buffer becomes non-full or timeout.
          * \param elem the new element to push
-         * \param time the timeout time
+         * \param timeout the timeout in seconds
          * \return false when the operation times out
          */
-        virtual bool push_with_timed_wait(const elem_type &elem, const time_duration_t &time) = 0;
+        virtual bool push_with_timed_wait(const elem_type &elem, double timeout) = 0;
 
         /*!
          * Pop an element from the bounded_buffer.
@@ -80,10 +76,10 @@ namespace uhd{ namespace transport{
          * Pop an element from the bounded_buffer.
          * Wait until the bounded_buffer becomes non-empty or timeout.
          * \param elem the element reference pop to
-         * \param time the timeout time
+         * \param timeout the timeout in seconds
          * \return false when the operation times out
          */
-        virtual bool pop_with_timed_wait(elem_type &elem, const time_duration_t &time) = 0;
+        virtual bool pop_with_timed_wait(elem_type &elem, double timeout) = 0;
 
         /*!
          * Clear all elements from the bounded_buffer.
diff --git a/host/include/uhd/transport/bounded_buffer.ipp b/host/include/uhd/transport/bounded_buffer.ipp
index e106e229e..edc7faa06 100644
--- a/host/include/uhd/transport/bounded_buffer.ipp
+++ b/host/include/uhd/transport/bounded_buffer.ipp
@@ -19,17 +19,28 @@
 #define INCLUDED_UHD_TRANSPORT_BOUNDED_BUFFER_IPP
 
 #include <boost/bind.hpp>
+#include <boost/function.hpp>
 #include <boost/circular_buffer.hpp>
 #include <boost/thread/condition.hpp>
+#include <boost/date_time/posix_time/posix_time_types.hpp>
 
 namespace uhd{ namespace transport{ namespace{ /*anon*/
 
+    static UHD_INLINE boost::posix_time::time_duration to_time_dur(double timeout){
+        return boost::posix_time::microseconds(long(timeout*1e6));
+    }
+
+    static UHD_INLINE double from_time_dur(const boost::posix_time::time_duration &time_dur){
+        return 1e-6*time_dur.total_microseconds();
+    }
+
     template <typename elem_type>
     class bounded_buffer_impl : public bounded_buffer<elem_type>{
     public:
 
         bounded_buffer_impl(size_t capacity) : _buffer(capacity){
-            /* NOP */
+            _not_full_fcn = boost::bind(&bounded_buffer_impl<elem_type>::not_full, this);
+            _not_empty_fcn = boost::bind(&bounded_buffer_impl<elem_type>::not_empty, this);
         }
 
         UHD_INLINE bool push_with_pop_on_full(const elem_type &elem){
@@ -51,15 +62,17 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
 
         UHD_INLINE void push_with_wait(const elem_type &elem){
             boost::unique_lock<boost::mutex> lock(_mutex);
-            _full_cond.wait(lock, boost::bind(&bounded_buffer_impl<elem_type>::not_full, this));
+            _full_cond.wait(lock, _not_full_fcn);
             _buffer.push_front(elem);
             lock.unlock();
             _empty_cond.notify_one();
         }
 
-        bool push_with_timed_wait(const elem_type &elem, const time_duration_t &time){
+        UHD_INLINE bool push_with_timed_wait(const elem_type &elem, double timeout){
             boost::unique_lock<boost::mutex> lock(_mutex);
-            if (not _full_cond.timed_wait(lock, time, boost::bind(&bounded_buffer_impl<elem_type>::not_full, this))) return false;
+            if (not _full_cond.timed_wait(
+                lock, to_time_dur(timeout), _not_full_fcn
+            )) return false;
             _buffer.push_front(elem);
             lock.unlock();
             _empty_cond.notify_one();
@@ -68,16 +81,18 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
 
         UHD_INLINE void pop_with_wait(elem_type &elem){
             boost::unique_lock<boost::mutex> lock(_mutex);
-            _empty_cond.wait(lock, boost::bind(&bounded_buffer_impl<elem_type>::not_empty, this));
-            elem = _buffer.back(); _buffer.pop_back();
+            _empty_cond.wait(lock, _not_empty_fcn);
+            elem = this->pop_back();
             lock.unlock();
             _full_cond.notify_one();
         }
 
-        bool pop_with_timed_wait(elem_type &elem, const time_duration_t &time){
+        UHD_INLINE bool pop_with_timed_wait(elem_type &elem, double timeout){
             boost::unique_lock<boost::mutex> lock(_mutex);
-            if (not _empty_cond.timed_wait(lock, time, boost::bind(&bounded_buffer_impl<elem_type>::not_empty, this))) return false;
-            elem = _buffer.back(); _buffer.pop_back();
+            if (not _empty_cond.timed_wait(
+                lock, to_time_dur(timeout), _not_empty_fcn
+            )) return false;
+            elem = this->pop_back();
             lock.unlock();
             _full_cond.notify_one();
             return true;
@@ -85,7 +100,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
 
         UHD_INLINE void clear(void){
             boost::unique_lock<boost::mutex> lock(_mutex);
-            while (not_empty()) _buffer.pop_back();
+            while (not_empty()) this->pop_back();
             lock.unlock();
             _full_cond.notify_one();
         }
@@ -97,6 +112,21 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
 
         bool not_full(void) const{return not _buffer.full();}
         bool not_empty(void) const{return not _buffer.empty();}
+
+        boost::function<bool(void)> _not_full_fcn, _not_empty_fcn;
+
+        /*!
+         * Three part operation to pop an element:
+         * 1) assign elem to the back element
+         * 2) assign the back element to empty
+         * 3) pop the back to move the counter
+         */
+        UHD_INLINE elem_type pop_back(void){
+            elem_type elem = _buffer.back();
+            _buffer.back() = elem_type();
+            _buffer.pop_back();
+            return elem;
+        }
     };
 }}} //namespace
 
diff --git a/host/include/uhd/transport/udp_zero_copy.hpp b/host/include/uhd/transport/udp_zero_copy.hpp
index 818709973..bbba97b21 100644
--- a/host/include/uhd/transport/udp_zero_copy.hpp
+++ b/host/include/uhd/transport/udp_zero_copy.hpp
@@ -20,6 +20,7 @@
 
 #include <uhd/config.hpp>
 #include <uhd/transport/zero_copy.hpp>
+#include <uhd/types/device_addr.hpp>
 #include <boost/shared_ptr.hpp>
 
 namespace uhd{ namespace transport{
@@ -50,14 +51,12 @@ public:
      *
      * \param addr a string representing the destination address
      * \param port a string representing the destination port
-     * \param recv_buff_size size in bytes for the recv buffer, 0 for automatic
-     * \param send_buff_size size in bytes for the send buffer, 0 for automatic
+     * \param hints optional parameters to pass to the underlying transport
      */
     static sptr make(
         const std::string &addr,
         const std::string &port,
-        size_t recv_buff_size = 0,
-        size_t send_buff_size = 0
+        const device_addr_t &hints = device_addr_t()
     );
 };
 
diff --git a/host/include/uhd/transport/usb_control.hpp b/host/include/uhd/transport/usb_control.hpp
index 6137ecf84..e6c32f78e 100644
--- a/host/include/uhd/transport/usb_control.hpp
+++ b/host/include/uhd/transport/usb_control.hpp
@@ -18,7 +18,7 @@
 #ifndef INCLUDED_UHD_TRANSPORT_USB_CONTROL_HPP
 #define INCLUDED_UHD_TRANSPORT_USB_CONTROL_HPP
 
-#include "usb_device_handle.hpp"
+#include <uhd/transport/usb_device_handle.hpp>
 
 namespace uhd { namespace transport {
 
@@ -50,9 +50,9 @@ public:
      * \param index        2-byte (wIndex)
      * \param buff         buffer to hold send or receive data
      * \param length       2-byte (wLength)
-     * \return             number of bytes submitted
+     * \return             number of bytes submitted or error code
      */
-    virtual size_t submit(boost::uint8_t request_type,
+    virtual ssize_t submit(boost::uint8_t request_type,
                           boost::uint8_t request,
                           boost::uint16_t value,
                           boost::uint16_t index, 
diff --git a/host/include/uhd/transport/usb_device_handle.hpp b/host/include/uhd/transport/usb_device_handle.hpp
index 735a3acbe..6f8d868be 100644
--- a/host/include/uhd/transport/usb_device_handle.hpp
+++ b/host/include/uhd/transport/usb_device_handle.hpp
@@ -38,7 +38,7 @@ namespace uhd { namespace transport {
  *       a true descriptor serial number string. This interface returns the
  *       actual string descriptor.
  */
-class usb_device_handle : boost::noncopyable {
+class UHD_API usb_device_handle : boost::noncopyable {
 public:
     typedef boost::shared_ptr<usb_device_handle> sptr;
 
@@ -61,12 +61,6 @@ public:
     virtual boost::uint16_t get_product_id() const = 0;
 
     /*!
-     * Return the device's USB address
-     * \return a Product ID
-     */
-    virtual boost::uint16_t get_device_addr() const = 0;
-
-    /*!
      * Return a vector of USB devices on this host 
      * \return a vector of USB device handles that match vid and pid
      */
diff --git a/host/include/uhd/transport/usb_zero_copy.hpp b/host/include/uhd/transport/usb_zero_copy.hpp
index 75232c22a..b39171fba 100644
--- a/host/include/uhd/transport/usb_zero_copy.hpp
+++ b/host/include/uhd/transport/usb_zero_copy.hpp
@@ -18,8 +18,9 @@
 #ifndef INCLUDED_UHD_TRANSPORT_USB_ZERO_COPY_HPP
 #define INCLUDED_UHD_TRANSPORT_USB_ZERO_COPY_HPP
 
-#include "usb_device_handle.hpp"
+#include <uhd/transport/usb_device_handle.hpp>
 #include <uhd/transport/zero_copy.hpp>
+#include <uhd/types/device_addr.hpp>
 
 namespace uhd { namespace transport {
 
@@ -45,16 +46,16 @@ public:
      * The underlying implementation may be platform specific.
      *
      * \param handle a device handle that uniquely identifying the device
-     * \param rx_endpoint an integer specifiying an IN endpoint number 
-     * \param tx_endpoint an integer specifiying an OUT endpoint number
-     * \param buff_size total number of bytes of buffer space to allocate 
-     * \param block_size number of bytes allocated for each I/O transaction 
+     * \param recv_endpoint an integer specifiying an IN endpoint number
+     * \param send_endpoint an integer specifiying an OUT endpoint number
+     * \param hints optional parameters to pass to the underlying transport
      */
-    static sptr make(usb_device_handle::sptr handle,
-                     unsigned int rx_endpoint,
-                     unsigned int tx_endpoint,
-                     size_t buff_size = 0,
-                     size_t block_size = 0);
+    static sptr make(
+        usb_device_handle::sptr handle,
+        size_t recv_endpoint,
+        size_t send_endpoint,
+        const device_addr_t &hints = device_addr_t()
+    );
 };
 
 }} //namespace
diff --git a/host/include/uhd/transport/zero_copy.hpp b/host/include/uhd/transport/zero_copy.hpp
index 513291b63..7d8fb4b83 100644
--- a/host/include/uhd/transport/zero_copy.hpp
+++ b/host/include/uhd/transport/zero_copy.hpp
@@ -19,10 +19,10 @@
 #define INCLUDED_UHD_TRANSPORT_ZERO_COPY_HPP
 
 #include <uhd/config.hpp>
-#include <uhd/utils/pimpl.hpp>
 #include <boost/asio/buffer.hpp>
 #include <boost/utility.hpp>
 #include <boost/shared_ptr.hpp>
+#include <boost/function.hpp>
 
 namespace uhd{ namespace transport{
 
@@ -34,14 +34,27 @@ namespace uhd{ namespace transport{
     class UHD_API managed_recv_buffer : boost::noncopyable{
     public:
         typedef boost::shared_ptr<managed_recv_buffer> sptr;
+        typedef boost::function<void(void)> release_fcn_t;
+
+        /*!
+         * Make a safe managed receive buffer:
+         * A safe managed buffer ensures that release is called once,
+         * either by the user or automatically upon deconstruction.
+         * \param buff a reference to the constant buffer
+         * \param release_fcn callback to release the memory
+         * \return a new managed receive buffer
+         */
+        static sptr make_safe(
+            const boost::asio::const_buffer &buff,
+            const release_fcn_t &release_fcn
+        );
 
         /*!
-         * Managed recv buffer destructor:
          * Signal to the transport that we are done with the buffer.
-         * This should be called to release the buffer to the transport.
+         * This should be called to release the buffer to the transport object.
          * After calling, the referenced memory should be considered invalid.
          */
-        virtual ~managed_recv_buffer(void) = 0;
+        virtual void release(void) = 0;
 
         /*!
          * Get the size of the underlying buffer.
@@ -71,20 +84,34 @@ namespace uhd{ namespace transport{
     /*!
      * A managed send buffer:
      * Contains a reference to transport-managed memory,
-     * and a method to release the memory after writing.
+     * and a method to commit the memory after writing.
      */
     class UHD_API managed_send_buffer : boost::noncopyable{
     public:
         typedef boost::shared_ptr<managed_send_buffer> sptr;
+        typedef boost::function<void(size_t)> commit_fcn_t;
+
+        /*!
+         * Make a safe managed send buffer:
+         * A safe managed buffer ensures that commit is called once,
+         * either by the user or automatically upon deconstruction.
+         * In the later case, the deconstructor will call commit(0).
+         * \param buff a reference to the mutable buffer
+         * \param commit_fcn callback to commit the memory
+         * \return a new managed send buffer
+         */
+        static sptr make_safe(
+            const boost::asio::mutable_buffer &buff,
+            const commit_fcn_t &commit_fcn
+        );
 
         /*!
          * Signal to the transport that we are done with the buffer.
          * This should be called to commit the write to the transport object.
          * After calling, the referenced memory should be considered invalid.
          * \param num_bytes the number of bytes written into the buffer
-         * \return the number of bytes written, 0 for timeout, negative for error
          */
-        virtual ssize_t commit(size_t num_bytes) = 0;
+        virtual void commit(size_t num_bytes) = 0;
 
         /*!
          * Get the size of the underlying buffer.
@@ -122,100 +149,46 @@ namespace uhd{ namespace transport{
 
         /*!
          * Get a new receive buffer from this transport object.
+         * \param timeout the timeout to get the buffer in seconds
          * \return a managed buffer, or null sptr on timeout/error
          */
-        virtual managed_recv_buffer::sptr get_recv_buff(void) = 0;
+        virtual managed_recv_buffer::sptr get_recv_buff(double timeout = 0.1) = 0;
 
         /*!
-         * Get the maximum number of receive frames:
-         *   The maximum number of valid managed recv buffers,
-         *   or the maximum number of frames in the ring buffer,
-         *   depending upon the underlying implementation.
+         * Get the number of receive frames:
+         * The number of simultaneous receive buffers in use.
          * \return number of frames
          */
         virtual size_t get_num_recv_frames(void) const = 0;
 
         /*!
+         * Get the size of a receive frame:
+         * The maximum capacity of a single receive buffer.
+         * \return frame size in bytes
+         */
+        virtual size_t get_recv_frame_size(void) const = 0;
+
+        /*!
          * Get a new send buffer from this transport object.
+         * \param timeout the timeout to get the buffer in seconds
          * \return a managed buffer, or null sptr on timeout/error
          */
-        virtual managed_send_buffer::sptr get_send_buff(void) = 0;
+        virtual managed_send_buffer::sptr get_send_buff(double timeout = 0.1) = 0;
 
         /*!
-         * Get the maximum number of send frames:
-         *   The maximum number of valid managed send buffers,
-         *   or the maximum number of frames in the ring buffer,
-         *   depending upon the underlying implementation.
+         * Get the number of send frames:
+         * The number of simultaneous send buffers in use.
          * \return number of frames
          */
         virtual size_t get_num_send_frames(void) const = 0;
 
-    };
-
-    /*!
-     * A phony-zero-copy interface for transport objects that
-     * provides a zero-copy interface on top of copying transport.
-     * This interface implements the get managed recv buffer,
-     * the base class must implement the private recv method.
-     */
-    class UHD_API phony_zero_copy_recv_if : public virtual zero_copy_if{
-    public:
-        /*!
-         * Create a phony zero copy recv interface.
-         * \param max_buff_size max buffer size in bytes
-         */
-        phony_zero_copy_recv_if(size_t max_buff_size);
-
-        //! destructor
-        virtual ~phony_zero_copy_recv_if(void);
-
-        /*!
-         * Get a new receive buffer from this transport object.
-         */
-        managed_recv_buffer::sptr get_recv_buff(void);
-
-    private:
-        /*!
-         * Perform a private copying recv.
-         * \param buff the buffer to write data into
-         * \return the number of bytes written to buff, 0 for timeout, negative for error
-         */
-        virtual ssize_t recv(const boost::asio::mutable_buffer &buff) = 0;
-
-        UHD_PIMPL_DECL(impl) _impl;
-    };
-
-    /*!
-     * A phony-zero-copy interface for transport objects that
-     * provides a zero-copy interface on top of copying transport.
-     * This interface implements the get managed send buffer,
-     * the base class must implement the private send method.
-     */
-    class UHD_API phony_zero_copy_send_if : public virtual zero_copy_if{
-    public:
-        /*!
-         * Create a phony zero copy send interface.
-         * \param max_buff_size max buffer size in bytes
-         */
-        phony_zero_copy_send_if(size_t max_buff_size);
-
-        //! destructor
-        virtual ~phony_zero_copy_send_if(void);
-
-        /*!
-         * Get a new send buffer from this transport object.
-         */
-        managed_send_buffer::sptr get_send_buff(void);
-
-    private:
         /*!
-         * Perform a private copying send.
-         * \param buff the buffer to read data from
-         * \return the number of bytes read from buff, 0 for timeout, negative for error
+         * Get the size of a send frame:
+         * The maximum capacity of a single send buffer.
+         * \return frame size in bytes
          */
-        virtual ssize_t send(const boost::asio::const_buffer &buff) = 0;
+        virtual size_t get_send_frame_size(void) const = 0;
 
-        UHD_PIMPL_DECL(impl) _impl;
     };
 
 }} //namespace
diff --git a/host/include/uhd/types/CMakeLists.txt b/host/include/uhd/types/CMakeLists.txt
index dbce21c98..a96976b5e 100644
--- a/host/include/uhd/types/CMakeLists.txt
+++ b/host/include/uhd/types/CMakeLists.txt
@@ -19,6 +19,7 @@
 INSTALL(FILES
     clock_config.hpp
     device_addr.hpp
+    dict.ipp
     dict.hpp
     io_type.hpp
     mac_addr.hpp
@@ -28,6 +29,7 @@ INSTALL(FILES
     serial.hpp
     stream_cmd.hpp
     time_spec.hpp
+    tune_request.hpp
     tune_result.hpp
     DESTINATION ${INCLUDE_DIR}/uhd/types
 )
diff --git a/host/include/uhd/types/device_addr.hpp b/host/include/uhd/types/device_addr.hpp
index e359d9467..eb3394230 100644
--- a/host/include/uhd/types/device_addr.hpp
+++ b/host/include/uhd/types/device_addr.hpp
@@ -20,6 +20,8 @@
 
 #include <uhd/config.hpp>
 #include <uhd/types/dict.hpp>
+#include <boost/lexical_cast.hpp>
+#include <stdexcept>
 #include <vector>
 #include <string>
 
@@ -62,6 +64,24 @@ namespace uhd{
          * \return a string with delimiter markup
          */
         std::string to_string(void) const;
+
+        /*!
+         * Lexically cast a parameter to the specified type,
+         * or use the default value if the key is not found.
+         * \param key the key as one of the address parameters
+         * \param def the value to use when key is not present
+         * \return the casted value as type T or the default
+         * \throw error when the parameter cannot be casted
+         */
+        template <typename T> T cast(const std::string &key, const T &def) const{
+            if (not this->has_key(key)) return def;
+            try{
+                return boost::lexical_cast<T>((*this)[key]);
+            }
+            catch(const boost::bad_lexical_cast &){
+                throw std::runtime_error("cannot cast " + key + " = " + (*this)[key]);
+            }
+        }
     };
 
     //handy typedef for a vector of device addresses
diff --git a/host/include/uhd/types/dict.hpp b/host/include/uhd/types/dict.hpp
index de96ea768..b14fc5425 100644
--- a/host/include/uhd/types/dict.hpp
+++ b/host/include/uhd/types/dict.hpp
@@ -19,11 +19,6 @@
 #define INCLUDED_UHD_TYPES_DICT_HPP
 
 #include <uhd/config.hpp>
-#include <boost/foreach.hpp>
-#include <boost/format.hpp>
-#include <boost/lexical_cast.hpp>
-#include <stdexcept>
-#include <typeinfo>
 #include <vector>
 #include <list>
 
@@ -34,14 +29,10 @@ namespace uhd{
      */
     template <typename Key, typename Val> class dict{
     public:
-        typedef std::pair<Key, Val> pair_t;
-
         /*!
          * Create a new empty dictionary.
          */
-        dict(void){
-            /* NOP */
-        }
+        dict(void);
 
         /*!
          * Input iterator constructor:
@@ -50,64 +41,34 @@ namespace uhd{
          * \param last the end iterator
          */
         template <typename InputIterator>
-        dict(InputIterator first, InputIterator last){
-            for(InputIterator it = first; it != last; it++){
-                _map.push_back(*it);
-            }
-        }
-
-        /*!
-         * Destroy this dict.
-         */
-        ~dict(void){
-            /* NOP */
-        }
+        dict(InputIterator first, InputIterator last);
 
         /*!
          * Get the number of elements in this dict.
          * \return the number of elements
          */
-        std::size_t size(void) const{
-            return _map.size();
-        }
+        std::size_t size(void) const;
 
         /*!
          * Get a list of the keys in this dict.
          * Key order depends on insertion precedence.
          * \return vector of keys
          */
-        const std::vector<Key> keys(void) const{
-            std::vector<Key> keys;
-            BOOST_FOREACH(const pair_t &p, _map){
-                keys.push_back(p.first);
-            }
-            return keys;
-        }
+        const std::vector<Key> keys(void) const;
 
         /*!
          * Get a list of the values in this dict.
          * Value order depends on insertion precedence.
          * \return vector of values
          */
-        const std::vector<Val> vals(void) const{
-            std::vector<Val> vals;
-            BOOST_FOREACH(const pair_t &p, _map){
-                vals.push_back(p.second);
-            }
-            return vals;
-        }
+        const std::vector<Val> vals(void) const;
 
         /*!
          * Does the dictionary contain this key?
          * \param key the key to look for
          * \return true if found
          */
-        bool has_key(const Key &key) const{
-            BOOST_FOREACH(const pair_t &p, _map){
-                if (p.first == key) return true;
-            }
-            return false;
-        }
+        bool has_key(const Key &key) const;
 
         /*!
          * Get a value for the given key if it exists.
@@ -116,15 +77,7 @@ namespace uhd{
          * \return the value at the key
          * \throw an exception when not found
          */
-        const Val &operator[](const Key &key) const{
-            BOOST_FOREACH(const pair_t &p, _map){
-                if (p.first == key) return p.second;
-            }
-            throw std::invalid_argument(str(boost::format(
-                "key \"%s\" not found in dict(%s, %s)"
-            ) % boost::lexical_cast<std::string>(key)
-            % typeid(Key).name() % typeid(Val).name()));
-        }
+        const Val &operator[](const Key &key) const;
 
         /*!
          * Set a value for the given key, however, in reality
@@ -132,13 +85,7 @@ namespace uhd{
          * \param key the key to set to
          * \return a reference to the value
          */
-        Val &operator[](const Key &key){
-            BOOST_FOREACH(pair_t &p, _map){
-                if (p.first == key) return p.second;
-            }
-            _map.push_back(std::make_pair(key, Val()));
-            return _map.back().second;
-        }
+        Val &operator[](const Key &key);
 
         /*!
          * Pop an item out of the dictionary.
@@ -146,16 +93,15 @@ namespace uhd{
          * \return the value of the item
          * \throw an exception when not found
          */
-        Val pop(const Key &key){
-            Val val = (*this)[key];
-            _map.remove(pair_t(key, val));
-            return val;
-        }
+        Val pop(const Key &key);
 
     private:
+        typedef std::pair<Key, Val> pair_t;
         std::list<pair_t> _map; //private container
     };
 
 } //namespace uhd
 
+#include <uhd/types/dict.ipp>
+
 #endif /* INCLUDED_UHD_TYPES_DICT_HPP */
diff --git a/host/include/uhd/types/dict.ipp b/host/include/uhd/types/dict.ipp
new file mode 100644
index 000000000..85071e6fd
--- /dev/null
+++ b/host/include/uhd/types/dict.ipp
@@ -0,0 +1,120 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_UHD_TYPES_DICT_IPP
+#define INCLUDED_UHD_TYPES_DICT_IPP
+
+#include <boost/foreach.hpp>
+#include <boost/format.hpp>
+#include <boost/lexical_cast.hpp>
+#include <stdexcept>
+#include <typeinfo>
+
+namespace uhd{
+
+    namespace /*anon*/{
+        template<typename Key, typename Val>
+        struct UHD_API key_not_found: std::out_of_range{
+            key_not_found(const Key &key): std::out_of_range(
+                str(boost::format(
+                    "key \"%s\" not found in dict(%s, %s)"
+                    ) % boost::lexical_cast<std::string>(key)
+                    % typeid(Key).name() % typeid(Val).name()
+                )
+            ){
+                /* NOP */
+            }
+        };
+    } // namespace /*anon*/
+
+    template <typename Key, typename Val>
+    dict<Key, Val>::dict(void){
+        /* NOP */
+    }
+
+    template <typename Key, typename Val>
+    template <typename InputIterator>
+    dict<Key, Val>::dict(InputIterator first, InputIterator last){
+        for(InputIterator it = first; it != last; it++){
+            _map.push_back(*it);
+        }
+    }
+
+    template <typename Key, typename Val>
+    std::size_t dict<Key, Val>::size(void) const{
+        return _map.size();
+    }
+
+    template <typename Key, typename Val>
+    const std::vector<Key> dict<Key, Val>::keys(void) const{
+        std::vector<Key> keys;
+        BOOST_FOREACH(const pair_t &p, _map){
+            keys.push_back(p.first);
+        }
+        return keys;
+    }
+
+    template <typename Key, typename Val>
+    const std::vector<Val> dict<Key, Val>::vals(void) const{
+        std::vector<Val> vals;
+        BOOST_FOREACH(const pair_t &p, _map){
+            vals.push_back(p.second);
+        }
+        return vals;
+    }
+
+    template <typename Key, typename Val>
+    bool dict<Key, Val>::has_key(const Key &key) const{
+        BOOST_FOREACH(const pair_t &p, _map){
+            if (p.first == key) return true;
+        }
+        return false;
+    }
+
+    template <typename Key, typename Val>
+    const Val &dict<Key, Val>::operator[](const Key &key) const{
+        BOOST_FOREACH(const pair_t &p, _map){
+            if (p.first == key) return p.second;
+        }
+        throw key_not_found<Key, Val>(key);
+    }
+
+    template <typename Key, typename Val>
+    Val &dict<Key, Val>::operator[](const Key &key){
+        BOOST_FOREACH(pair_t &p, _map){
+            if (p.first == key) return p.second;
+        }
+        _map.push_back(std::make_pair(key, Val()));
+        return _map.back().second;
+    }
+
+    template <typename Key, typename Val>
+    Val dict<Key, Val>::pop(const Key &key){
+        typename std::list<pair_t>::iterator it;
+        for (it = _map.begin(); it != _map.end(); it++){
+            if (it->first == key){
+                Val val = it->second;
+                _map.erase(it);
+                return val;
+            }
+        }
+        throw key_not_found<Key, Val>(key);
+    }
+
+} //namespace uhd
+
+#endif /* INCLUDED_UHD_TYPES_DICT_IPP */
diff --git a/host/include/uhd/types/metadata.hpp b/host/include/uhd/types/metadata.hpp
index 65952941c..3f250d13e 100644
--- a/host/include/uhd/types/metadata.hpp
+++ b/host/include/uhd/types/metadata.hpp
@@ -19,7 +19,6 @@
 #define INCLUDED_UHD_TYPES_METADATA_HPP
 
 #include <uhd/config.hpp>
-#include <boost/cstdint.hpp>
 #include <uhd/types/time_spec.hpp>
 
 namespace uhd{
@@ -30,58 +29,59 @@ namespace uhd{
      * The receive routines will convert IF data headers into metadata.
      */
     struct UHD_API rx_metadata_t{
-        /*!
-         * Time specification:
-         * Set from timestamps on incoming data when provided.
-         */
+        //! Has time specification?
         bool has_time_spec;
+
+        //! Time of the first sample.
         time_spec_t time_spec;
 
         /*!
-         * Fragmentation flag and offset:
+         * Fragmentation flag:
          * Similar to IPv4 fragmentation: http://en.wikipedia.org/wiki/IPv4#Fragmentation_and_reassembly
          * More fragments is true when the input buffer has insufficient size to fit
          * an entire received packet. More fragments will be false for the last fragment.
-         * The fragment offset is the sample number at the start of the receive buffer.
-         * For non-fragmented receives, the fragment offset should always be zero.
          */
         bool more_fragments;
-        size_t fragment_offset;
 
         /*!
-         * Burst flags:
-         * Start of burst will be true for the first packet in the chain.
-         * End of burst will be true for the last packet in the chain.
+         * Fragmentation offset:
+         * The fragment offset is the sample number at the start of the receive buffer.
+         * For non-fragmented receives, the fragment offset should always be zero.
          */
+        size_t fragment_offset;
+
+        //! Start of burst will be true for the first packet in the chain.
         bool start_of_burst;
+
+        //! End of burst will be true for the last packet in the chain.
         bool end_of_burst;
 
         /*!
-         * Error conditions:
-         * - none: no error associated with this metadata
-         * - timeout: no packet received, underlying code timed-out
-         * - late command: a stream command was issued in the past
-         * - broken chain: expected another stream command
-         * - overflow: an internal receive buffer has filled
-         * - bad packet: the buffer was unrecognizable as a vrt packet
+         * The error condition on a receive call.
          *
          * Note: When an overrun occurs in continuous streaming mode,
          * the device will continue to send samples to the host.
          * For other streaming modes, streaming will discontinue
          * until the user issues a new stream command.
          *
-         * Note: The metadata fields have meaning for the following error codes:
+         * The metadata fields have meaning for the following error codes:
          * - none
          * - late command
          * - broken chain
          * - overflow
          */
         enum error_code_t {
+            //! No error associated with this metadata.
             ERROR_CODE_NONE         = 0x0,
+            //! No packet received, implementation timed-out.
             ERROR_CODE_TIMEOUT      = 0x1,
+            //! A stream command was issued in the past.
             ERROR_CODE_LATE_COMMAND = 0x2,
+            //! Expected another stream command.
             ERROR_CODE_BROKEN_CHAIN = 0x4,
+            //! An internal receive buffer has filled.
             ERROR_CODE_OVERFLOW     = 0x8,
+            //! The packet could not be parsed.
             ERROR_CODE_BAD_PACKET   = 0xf
         } error_code;
     };
@@ -93,19 +93,19 @@ namespace uhd{
      */
     struct UHD_API tx_metadata_t{
         /*!
-         * Time specification:
-         * Set has time spec to false to perform a send "now".
-         * Or, set to true, and fill in time spec for a send "at".
+         * Has time specification?
+         * - Set false to send immediately.
+         * - Set true to send at the time specified by time spec.
          */
         bool has_time_spec;
+
+        //! When to send the first sample.
         time_spec_t time_spec;
 
-        /*!
-         * Burst flags:
-         * Set start of burst to true for the first packet in the chain.
-         * Set end of burst to true for the last packet in the chain.
-         */
+        //! Set start of burst to true for the first packet in the chain.
         bool start_of_burst;
+
+        //! Set end of burst to true for the last packet in the chain.
         bool end_of_burst;
 
         /*!
@@ -122,27 +122,27 @@ namespace uhd{
         //! The channel number in a mimo configuration
         size_t channel;
 
-        /*!
-         * Time specification: when the async event occurred.
-         */
+        //! Has time specification?
         bool has_time_spec;
+
+        //! When the async event occurred.
         time_spec_t time_spec;
 
         /*!
-         * Event codes:
-         * - success: a packet was successfully transmitted
-         * - underflow: an internal send buffer has emptied
-         * - sequence error: packet loss between host and device
-         * - time error: packet had time that was late (or too early)
-         * - underflow in packet: underflow occurred inside a packet
-         * - sequence error in burst: packet loss within a burst
+         * The type of event for a receive async message call.
          */
         enum event_code_t {
+            //! A packet was successfully transmitted.
             EVENT_CODE_SUCCESS    = 0x1,
+            //! An internal send buffer has emptied.
             EVENT_CODE_UNDERFLOW  = 0x2,
+            //! Packet loss between host and device.
             EVENT_CODE_SEQ_ERROR  = 0x4,
+            //! Packet had time that was late (or too early).
             EVENT_CODE_TIME_ERROR = 0x8,
+            //! Underflow occurred inside a packet.
             EVENT_CODE_UNDERFLOW_IN_PACKET = 0x10,
+            //! Packet loss within a burst.
             EVENT_CODE_SEQ_ERROR_IN_BURST  = 0x20
         } event_code;
     };
diff --git a/host/include/uhd/types/time_spec.hpp b/host/include/uhd/types/time_spec.hpp
index 59b85f4b7..57d002d48 100644
--- a/host/include/uhd/types/time_spec.hpp
+++ b/host/include/uhd/types/time_spec.hpp
@@ -59,7 +59,7 @@ namespace uhd{
          * \param tick_count the fractional seconds tick count
          * \param tick_rate the number of ticks per second
          */
-        time_spec_t(time_t full_secs, size_t tick_count, double tick_rate);
+        time_spec_t(time_t full_secs, long tick_count, double tick_rate);
 
         /*!
          * Convert the fractional seconds to clock ticks.
@@ -67,7 +67,7 @@ namespace uhd{
          * \param tick_rate the number of ticks per second
          * \return the fractional seconds tick count
          */
-        size_t get_tick_count(double tick_rate) const;
+        long get_tick_count(double tick_rate) const;
 
         /*!
          * Get the time as a real-valued seconds count.
diff --git a/host/include/uhd/types/tune_request.hpp b/host/include/uhd/types/tune_request.hpp
new file mode 100644
index 000000000..942b93251
--- /dev/null
+++ b/host/include/uhd/types/tune_request.hpp
@@ -0,0 +1,95 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_UHD_TYPES_TUNE_REQUEST_HPP
+#define INCLUDED_UHD_TYPES_TUNE_REQUEST_HPP
+
+#include <uhd/config.hpp>
+
+namespace uhd{
+
+    /*!
+     * A tune request instructs the implementation how to tune the RF chain.
+     * The policies can be used to select automatic tuning or
+     * fined control over the daughterboard IF and DSP tuning.
+     * Not all combinations of policies are applicable.
+     * Convenience constructors are supplied for most use cases.
+     */
+    struct UHD_API tune_request_t{
+        /*!
+         * Make a new tune request for a particular center frequency.
+         * Use an automatic policy for the intermediate and DSP frequency
+         * to tune the chain as close as possible to the target frequency.
+         * \param target_freq the target frequency in Hz
+         */
+        tune_request_t(double target_freq = 0);
+
+        /*!
+         * Make a new tune request for a particular center frequency.
+         * Use a manual policy for the intermediate frequency,
+         * and an automatic policy for the DSP frequency,
+         * to tune the chain as close as possible to the target frequency.
+         * \param target_freq the target frequency in Hz
+         * \param lo_off the LO offset frequency in Hz
+         */
+        tune_request_t(double target_freq, double lo_off);
+
+        //! Policy options for tunable elements in the RF chain.
+        enum policy_t {
+            //! Do not set this argument, use current setting.
+            POLICY_NONE   = 'N',
+            //! Automatically determine the argument's value.
+            POLICY_AUTO   = 'A',
+            //! Use the argument's value for the setting.
+            POLICY_MANUAL = 'M'
+        };
+
+        /*!
+         * The target frequency of the overall chain in Hz.
+         * Set this even if all policies are set to manual.
+         */
+        double target_freq;
+
+        /*!
+         * The policy for the intermediate frequency.
+         * Automatic behavior: the target frequency + default LO offset.
+         */
+        policy_t inter_freq_policy;
+
+        /*!
+         * The intermediate frequency in Hz.
+         * Set when the policy is set to manual.
+         */
+        double inter_freq;
+
+        /*!
+         * The policy for the DSP frequency.
+         * Automatic behavior: the difference between the target and IF.
+         */
+        policy_t dsp_freq_policy;
+
+        /*!
+         * The DSP frequency in Hz.
+         * Set when the policy is set to manual.
+         */
+        double dsp_freq;
+
+    };
+
+} //namespace uhd
+
+#endif /* INCLUDED_UHD_TYPES_TUNE_REQUEST_HPP */
diff --git a/host/include/uhd/usrp/CMakeLists.txt b/host/include/uhd/usrp/CMakeLists.txt
index f973e401a..abddf3951 100644
--- a/host/include/uhd/usrp/CMakeLists.txt
+++ b/host/include/uhd/usrp/CMakeLists.txt
@@ -42,6 +42,7 @@ INSTALL(FILES
     simple_usrp.hpp
     single_usrp.hpp
     mimo_usrp.hpp
+    multi_usrp.hpp
 
     DESTINATION ${INCLUDE_DIR}/uhd/usrp
 )
diff --git a/host/include/uhd/usrp/dboard_id.hpp b/host/include/uhd/usrp/dboard_id.hpp
index 4c45e4334..1fda8182e 100644
--- a/host/include/uhd/usrp/dboard_id.hpp
+++ b/host/include/uhd/usrp/dboard_id.hpp
@@ -67,6 +67,12 @@ namespace uhd{ namespace usrp{
         std::string to_string(void) const;
 
         /*!
+         * Get the dboard id represented as a canonical name.
+         * \return the canonical string representation
+         */
+        std::string to_cname(void) const;
+
+        /*!
          * Get the pretty print representation of this dboard id.
          * \return a string with the dboard name and id number
          */
diff --git a/host/include/uhd/usrp/dboard_iface.hpp b/host/include/uhd/usrp/dboard_iface.hpp
index c7db244f2..c430ecd3f 100644
--- a/host/include/uhd/usrp/dboard_iface.hpp
+++ b/host/include/uhd/usrp/dboard_iface.hpp
@@ -242,6 +242,15 @@ public:
      * \param enb true for enabled
      */
     virtual void set_clock_enabled(unit_t unit, bool enb) = 0;
+
+    /*!
+     * Get the rate of the codec.
+     * For rx, this is the rate the ADC feeds the DSP.
+     * For tx, this is the rate the DSP feeds the DAC.
+     * \param unit which unit rx or tx
+     * \return the codec rate in Hz
+     */
+    virtual double get_codec_rate(unit_t unit) = 0;
 };
 
 }} //namespace
diff --git a/host/include/uhd/usrp/mimo_usrp.hpp b/host/include/uhd/usrp/mimo_usrp.hpp
index 10a404059..a2092f04f 100644
--- a/host/include/uhd/usrp/mimo_usrp.hpp
+++ b/host/include/uhd/usrp/mimo_usrp.hpp
@@ -32,12 +32,12 @@
 namespace uhd{ namespace usrp{
 
 /*!
- * The MIMO USRP device class:
+ * The MIMO USRP device class (DEPRECATED):
  * A mimo usrp facilitates ease-of-use for multi-usrp scenarios.
  * The wrapper provides convenience functions to control the group
  * of underlying devices as if they consisted of a single device.
  */
-class UHD_API mimo_usrp : boost::noncopyable{
+class UHD_API UHD_DEPRECATED mimo_usrp : boost::noncopyable{
 public:
     typedef boost::shared_ptr<mimo_usrp> sptr;
 
@@ -127,7 +127,7 @@ public:
     virtual double get_rx_rate_all(void) = 0;
 
     virtual tune_result_t set_rx_freq(size_t chan, double freq) = 0;
-    virtual tune_result_t set_rx_freq(size_t chan, double freq, double lo_off) = 0;
+    //virtual tune_result_t set_rx_freq(size_t chan, double freq, double lo_off) = 0;
     virtual double get_rx_freq(size_t chan) = 0;
     virtual freq_range_t get_rx_freq_range(size_t chan) = 0;
 
@@ -148,6 +148,8 @@ public:
      * \return the rssi in dB
      */
     virtual float read_rssi(size_t chan) = 0;
+    
+    virtual void set_rx_bandwidth(size_t chan, float bandwidth) = 0;
 
     /*******************************************************************
      * TX methods
@@ -159,7 +161,7 @@ public:
     virtual double get_tx_rate_all(void) = 0;
 
     virtual tune_result_t set_tx_freq(size_t chan, double freq) = 0;
-    virtual tune_result_t set_tx_freq(size_t chan, double freq, double lo_off) = 0;
+    //virtual tune_result_t set_tx_freq(size_t chan, double freq, double lo_off) = 0;
     virtual double get_tx_freq(size_t chan) = 0;
     virtual freq_range_t get_tx_freq_range(size_t chan) = 0;
 
@@ -177,4 +179,347 @@ public:
 
 }}
 
+#include <uhd/utils/warning.hpp>
+#include <uhd/usrp/tune_helper.hpp>
+#include <uhd/utils/assert.hpp>
+#include <uhd/utils/gain_group.hpp>
+#include <uhd/utils/algorithm.hpp>
+#include <uhd/utils/warning.hpp>
+#include <uhd/usrp/subdev_props.hpp>
+#include <uhd/usrp/mboard_props.hpp>
+#include <uhd/usrp/device_props.hpp>
+#include <uhd/usrp/dboard_props.hpp>
+#include <uhd/usrp/dsp_props.hpp>
+#include <boost/foreach.hpp>
+#include <boost/format.hpp>
+#include <boost/thread.hpp>
+#include <stdexcept>
+#include <iostream>
+
+namespace uhd{ namespace usrp{ namespace /*anon*/{
+
+static inline freq_range_t add_dsp_shift(const freq_range_t &range, wax::obj dsp){
+    double codec_rate = dsp[DSP_PROP_CODEC_RATE].as<double>();
+    return freq_range_t(range.min - codec_rate/2.0, range.max + codec_rate/2.0);
+}
+
+/***********************************************************************
+ * MIMO USRP Implementation
+ **********************************************************************/
+class mimo_usrp_impl : public mimo_usrp{
+public:
+    mimo_usrp_impl(const device_addr_t &addr){
+        _dev = device::make(addr);
+
+        //set the clock config across all mboards (TODO set through api)
+        clock_config_t clock_config;
+        clock_config.ref_source = clock_config_t::REF_SMA;
+        clock_config.pps_source = clock_config_t::PPS_SMA;
+        for (size_t chan = 0; chan < get_num_channels(); chan++){
+            _mboard(chan)[MBOARD_PROP_CLOCK_CONFIG] = clock_config;
+        }
+    }
+
+    ~mimo_usrp_impl(void){
+        /* NOP */
+    }
+
+    device::sptr get_device(void){
+        return _dev;
+    }
+
+    std::string get_pp_string(void){
+        std::string buff = str(boost::format(
+            "MIMO USRP:\n"
+            "  Device: %s\n"
+        )
+            % (*_dev)[DEVICE_PROP_NAME].as<std::string>()
+        );
+        for (size_t chan = 0; chan < get_num_channels(); chan++){
+            buff += str(boost::format(
+                "  Channel: %u\n"
+                "    Mboard: %s\n"
+                "    RX DSP: %s\n"
+                "    RX Dboard: %s\n"
+                "    RX Subdev: %s\n"
+                "    TX DSP: %s\n"
+                "    TX Dboard: %s\n"
+                "    TX Subdev: %s\n"
+            ) % chan
+                % _mboard(chan)[MBOARD_PROP_NAME].as<std::string>()
+                % _rx_dsp(chan)[DSP_PROP_NAME].as<std::string>()
+                % _rx_dboard(chan)[DBOARD_PROP_NAME].as<std::string>()
+                % _rx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>()
+                % _tx_dsp(chan)[DSP_PROP_NAME].as<std::string>()
+                % _tx_dboard(chan)[DBOARD_PROP_NAME].as<std::string>()
+                % _tx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>()
+            );
+        }
+        return buff;
+    }
+
+    size_t get_num_channels(void){
+        return (*_dev)[DEVICE_PROP_MBOARD_NAMES].as<prop_names_t>().size();
+    }
+
+    /*******************************************************************
+     * Misc
+     ******************************************************************/
+    time_spec_t get_time_now(void){
+        //the time on the first mboard better be the same on all
+        return _mboard(0)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
+    }
+
+    void set_time_next_pps(const time_spec_t &time_spec){
+        for (size_t chan = 0; chan < get_num_channels(); chan++){
+            _mboard(chan)[MBOARD_PROP_TIME_NEXT_PPS] = time_spec;
+        }
+    }
+
+    void set_time_unknown_pps(const time_spec_t &time_spec){
+        std::cout << "Set time with unknown pps edge:" << std::endl;
+        std::cout << "    1) set times next pps (race condition)" << std::endl;
+        set_time_next_pps(time_spec);
+        boost::this_thread::sleep(boost::posix_time::seconds(1));
+
+        std::cout << "    2) catch seconds rollover at pps edge" << std::endl;
+        time_t last_secs = 0, curr_secs = 0;
+        while(curr_secs == last_secs){
+            last_secs = curr_secs;
+            curr_secs = get_time_now().get_full_secs();
+        }
+
+        std::cout << "    3) set times next pps (synchronously)" << std::endl;
+        set_time_next_pps(time_spec);
+        boost::this_thread::sleep(boost::posix_time::seconds(1));
+
+        //verify that the time registers are read to be within a few RTT
+        for (size_t chan = 1; chan < get_num_channels(); chan++){
+            time_spec_t time_0 = _mboard(0)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
+            time_spec_t time_i = _mboard(chan)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
+            if (time_i < time_0 or (time_i - time_0) > time_spec_t(0.01)){ //10 ms: greater than RTT but not too big
+                uhd::warning::post(str(boost::format(
+                    "Detected time deviation between board %d and board 0.\n"
+                    "Board 0 time is %f seconds.\n"
+                    "Board %d time is %f seconds.\n"
+                ) % chan % time_0.get_real_secs() % chan % time_i.get_real_secs()));
+            }
+        }
+    }
+
+    void issue_stream_cmd(const stream_cmd_t &stream_cmd){
+        for (size_t chan = 0; chan < get_num_channels(); chan++){
+            _mboard(chan)[MBOARD_PROP_STREAM_CMD] = stream_cmd;
+        }
+    }
+
+    /*******************************************************************
+     * RX methods
+     ******************************************************************/
+    void set_rx_subdev_spec(size_t chan, const subdev_spec_t &spec){
+        UHD_ASSERT_THROW(spec.size() <= 1);
+        _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC] = spec;
+    }
+
+    subdev_spec_t get_rx_subdev_spec(size_t chan){
+        return _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>();
+    }
+
+    void set_rx_rate_all(double rate){
+        std::vector<double> _actual_rates;
+        for (size_t chan = 0; chan < get_num_channels(); chan++){
+            _rx_dsp(chan)[DSP_PROP_HOST_RATE] = rate;
+            _actual_rates.push_back(_rx_dsp(chan)[DSP_PROP_HOST_RATE].as<double>());
+        }
+        _rx_rate = _actual_rates.front();
+        if (std::count(_actual_rates, _rx_rate) != _actual_rates.size()) throw std::runtime_error(
+            "MIMO configuratio error: rx rate inconsistent across mboards"
+        );
+    }
+
+    double get_rx_rate_all(void){
+        return _rx_rate;
+    }
+
+    tune_result_t set_rx_freq(size_t chan, double target_freq){
+        return tune_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(chan), 0, target_freq);
+    }
+
+    //tune_result_t set_rx_freq(size_t chan, double target_freq, double lo_off){
+    //    return tune_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(chan), 0, target_freq, lo_off);
+    //}
+
+    double get_rx_freq(size_t chan){
+        return derive_freq_from_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(chan), 0);
+    }
+
+    freq_range_t get_rx_freq_range(size_t chan){
+        return add_dsp_shift(_rx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _rx_dsp(chan));
+    }
+
+    void set_rx_gain(size_t chan, float gain){
+        return _rx_gain_group(chan)->set_value(gain);
+    }
+
+    float get_rx_gain(size_t chan){
+        return _rx_gain_group(chan)->get_value();
+    }
+
+    gain_range_t get_rx_gain_range(size_t chan){
+        return _rx_gain_group(chan)->get_range();
+    }
+
+    void set_rx_antenna(size_t chan, const std::string &ant){
+        _rx_subdev(chan)[SUBDEV_PROP_ANTENNA] = ant;
+    }
+
+    std::string get_rx_antenna(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_ANTENNA].as<std::string>();
+    }
+
+    std::vector<std::string> get_rx_antennas(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_ANTENNA_NAMES].as<prop_names_t>();
+    }
+
+    bool get_rx_lo_locked(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
+    }
+
+    float read_rssi(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_RSSI].as<float>();
+    }
+    
+    void set_rx_bandwidth(size_t chan, float bandwidth){
+        _rx_subdev(chan)[SUBDEV_PROP_BANDWIDTH] = bandwidth;
+    }
+
+    /*******************************************************************
+     * TX methods
+     ******************************************************************/
+    void set_tx_subdev_spec(size_t chan, const subdev_spec_t &spec){
+        UHD_ASSERT_THROW(spec.size() <= 1);
+        _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC] = spec;
+    }
+
+    subdev_spec_t get_tx_subdev_spec(size_t chan){
+        return _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>();
+    }
+
+    void set_tx_rate_all(double rate){
+        std::vector<double> _actual_rates;
+        for (size_t chan = 0; chan < get_num_channels(); chan++){
+            _tx_dsp(chan)[DSP_PROP_HOST_RATE] = rate;
+            _actual_rates.push_back(_tx_dsp(chan)[DSP_PROP_HOST_RATE].as<double>());
+        }
+        _tx_rate = _actual_rates.front();
+        if (std::count(_actual_rates, _tx_rate) != _actual_rates.size()) throw std::runtime_error(
+            "MIMO configuratio error: tx rate inconsistent across mboards"
+        );
+    }
+
+    double get_tx_rate_all(void){
+        return _tx_rate;
+    }
+
+    tune_result_t set_tx_freq(size_t chan, double target_freq){
+        return tune_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(chan), 0, target_freq);
+    }
+
+    //tune_result_t set_tx_freq(size_t chan, double target_freq, double lo_off){
+    //    return tune_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(chan), 0, target_freq, lo_off);
+    //}
+
+    double get_tx_freq(size_t chan){
+        return derive_freq_from_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(chan), 0);
+    }
+
+    freq_range_t get_tx_freq_range(size_t chan){
+        return add_dsp_shift(_tx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _tx_dsp(chan));
+    }
+
+    void set_tx_gain(size_t chan, float gain){
+        return _tx_gain_group(chan)->set_value(gain);
+    }
+
+    float get_tx_gain(size_t chan){
+        return _tx_gain_group(chan)->get_value();
+    }
+
+    gain_range_t get_tx_gain_range(size_t chan){
+        return _tx_gain_group(chan)->get_range();
+    }
+
+    void set_tx_antenna(size_t chan, const std::string &ant){
+        _tx_subdev(chan)[SUBDEV_PROP_ANTENNA] = ant;
+    }
+
+    std::string get_tx_antenna(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_ANTENNA].as<std::string>();
+    }
+
+    std::vector<std::string> get_tx_antennas(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_ANTENNA_NAMES].as<prop_names_t>();
+    }
+
+    bool get_tx_lo_locked(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
+    }
+
+private:
+    device::sptr _dev;
+    wax::obj _mboard(size_t chan){
+        prop_names_t names = (*_dev)[DEVICE_PROP_MBOARD_NAMES].as<prop_names_t>();
+        return (*_dev)[named_prop_t(DEVICE_PROP_MBOARD, names.at(chan))];
+    }
+    wax::obj _rx_dsp(size_t chan){
+        return _mboard(chan)[MBOARD_PROP_RX_DSP];
+    }
+    wax::obj _tx_dsp(size_t chan){
+        return _mboard(chan)[MBOARD_PROP_TX_DSP];
+    }
+    wax::obj _rx_dboard(size_t chan){
+        std::string db_name = _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>().front().db_name;
+        return _mboard(chan)[named_prop_t(MBOARD_PROP_RX_DBOARD, db_name)];
+    }
+    wax::obj _tx_dboard(size_t chan){
+        std::string db_name = _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>().front().db_name;
+        return _mboard(chan)[named_prop_t(MBOARD_PROP_TX_DBOARD, db_name)];
+    }
+    wax::obj _rx_subdev(size_t chan){
+        std::string sd_name = _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>().front().sd_name;
+        return _rx_dboard(chan)[named_prop_t(DBOARD_PROP_SUBDEV, sd_name)];
+    }
+    wax::obj _tx_subdev(size_t chan){
+        std::string sd_name = _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>().front().sd_name;
+        return _tx_dboard(chan)[named_prop_t(DBOARD_PROP_SUBDEV, sd_name)];
+    }
+    gain_group::sptr _rx_gain_group(size_t chan){
+        std::string sd_name = _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>().front().sd_name;
+        return _rx_dboard(chan)[named_prop_t(DBOARD_PROP_GAIN_GROUP, sd_name)].as<gain_group::sptr>();
+    }
+    gain_group::sptr _tx_gain_group(size_t chan){
+        std::string sd_name = _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>().front().sd_name;
+        return _tx_dboard(chan)[named_prop_t(DBOARD_PROP_GAIN_GROUP, sd_name)].as<gain_group::sptr>();
+    }
+
+    //shadows
+    double _rx_rate, _tx_rate;
+};
+}}}
+
+namespace uhd{ namespace usrp{
+/***********************************************************************
+ * The Make Function
+ **********************************************************************/
+inline mimo_usrp::sptr mimo_usrp::make(const device_addr_t &dev_addr){
+    uhd::warning::post(
+        "The mimo USRP interface has been deprecated.\n"
+        "Please switch to the multi USRP interface.\n"
+        "#include <uhd/usrp/multi_usrp.hpp>\n"
+        "multi_usrp::sptr sdev = multi_usrp::make(args);\n"
+    );
+    return sptr(new mimo_usrp_impl(dev_addr));
+}
+}}
+
 #endif /* INCLUDED_UHD_USRP_MIMO_USRP_HPP */
diff --git a/host/include/uhd/usrp/misc_utils.hpp b/host/include/uhd/usrp/misc_utils.hpp
index 2af9f5b40..37860a1a5 100644
--- a/host/include/uhd/usrp/misc_utils.hpp
+++ b/host/include/uhd/usrp/misc_utils.hpp
@@ -20,6 +20,7 @@
 
 #include <uhd/config.hpp>
 #include <uhd/wax.hpp>
+#include <uhd/usrp/dboard_id.hpp>
 #include <uhd/usrp/subdev_spec.hpp>
 #include <uhd/utils/gain_group.hpp>
 
@@ -35,11 +36,13 @@ namespace uhd{ namespace usrp{
 
     /*!
      * Create a gain group that represents the subdevice and its codec.
+     * \param dboard_id the dboard id for this subdevice
      * \param subdev the object with subdevice properties
      * \param codec the object with codec properties
      * \param gain_group_policy the policy to use
      */
     UHD_API gain_group::sptr make_gain_group(
+        const dboard_id_t &dboard_id,
         wax::obj subdev, wax::obj codec,
         gain_group_policy_t gain_group_policy
     );
diff --git a/host/include/uhd/usrp/multi_usrp.hpp b/host/include/uhd/usrp/multi_usrp.hpp
new file mode 100644
index 000000000..98ba07fc0
--- /dev/null
+++ b/host/include/uhd/usrp/multi_usrp.hpp
@@ -0,0 +1,530 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_UHD_USRP_MULTI_USRP_HPP
+#define INCLUDED_UHD_USRP_MULTI_USRP_HPP
+
+#include <uhd/config.hpp>
+#include <uhd/device.hpp>
+#include <uhd/types/ranges.hpp>
+#include <uhd/types/stream_cmd.hpp>
+#include <uhd/types/clock_config.hpp>
+#include <uhd/types/tune_request.hpp>
+#include <uhd/types/tune_result.hpp>
+#include <uhd/usrp/subdev_spec.hpp>
+#include <uhd/usrp/dboard_iface.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/utility.hpp>
+#include <vector>
+
+namespace uhd{ namespace usrp{
+
+/*!
+ * The multi-USRP device class:
+ * A multi-USRP facilitates ease-of-use for multiple USRP scenarios.
+ * The wrapper provides convenience functions to control the group
+ * of underlying devices as if they consisted of a single device.
+ *
+ * A few notes about a multi-USRP configuration:
+ *  - All boards share a common RX sample rate
+ *  - All boards share a common TX sample rate
+ *  - All boards share a common RX subdevice specification size
+ *  - All boards share a common TX subdevice specification size
+ *  - All boards must have synchronized times (see the set_time_*() calls)
+ *
+ * Example to setup channel mapping:
+ * <pre>
+ *
+ * //create a multi_usrp with two boards in the configuration
+ * device_addr_t dev_addr;
+ * dev_addr["addr"] = "192.168.10.2 192.168.10.3";
+ * multi_usrp::sptr dev = multi_usrp::make(dev_addr);
+ *
+ * //set the board on 10.2 to use the A RX subdevice (RX channel 0)
+ * dev->set_rx_subdev_spec(":A", 0);
+ *
+ * //set the board on 10.3 to use the B RX subdevice (RX channel 1)
+ * dev->set_rx_subdev_spec(":B", 1);
+ *
+ * //set both boards to use the AB TX subdevice (TX channels 0 and 1)
+ * dev->set_tx_subdev_spec(":AB", multi_usrp::ALL_MBOARDS);
+ *
+ * //now that all the channels are mapped, continue with configuration...
+ *
+ * </pre>
+ */
+class UHD_API multi_usrp : boost::noncopyable{
+public:
+    typedef boost::shared_ptr<multi_usrp> sptr;
+
+    //! A wildcard motherboard index
+    static const size_t ALL_MBOARDS = size_t(~0);
+
+    //! A wildcard gain element name
+    static const std::string ALL_GAINS;
+
+    /*!
+     * Make a new multi usrp from the device address.
+     * \param dev_addr the device address
+     * \return a new single usrp object
+     */
+    static sptr make(const device_addr_t &dev_addr);
+
+    /*!
+     * Get the underlying device object.
+     * This is needed to get access to the streaming API and properties.
+     * \return the device object within this single usrp
+     */
+    virtual device::sptr get_device(void) = 0;
+
+    /*******************************************************************
+     * Mboard methods
+     ******************************************************************/
+    /*!
+     * Get a printable summary for this USRP configuration.
+     * \return a printable string
+     */
+    virtual std::string get_pp_string(void) = 0;
+
+    /*!
+     * Get canonical name for this USRP motherboard.
+     * \param mboard which motherboard to query
+     * \return a string representing the name
+     */
+    virtual std::string get_mboard_name(size_t mboard) = 0;
+
+    /*!
+     * Gets the current time in the usrp time registers.
+     * \return a timespec representing current usrp time
+     */
+    virtual time_spec_t get_time_now(void) = 0;
+
+    /*!
+     * Set the time registers on the usrp at the next pps tick.
+     * The values will not be latched in until the pulse occurs.
+     * It is recommended that the user sleep(1) after calling to ensure
+     * that the time registers will be in a known state prior to use.
+     *
+     * Note: Because this call sets the time on the "next" pps,
+     * the seconds in the time spec should be current seconds + 1.
+     *
+     * \param time_spec the time to latch into the usrp device
+     */
+    virtual void set_time_next_pps(const time_spec_t &time_spec) = 0;
+
+    /*!
+     * Synchronize the times across all motherboards in this configuration.
+     * Use this method to sync the times when the edge of the PPS is unknown.
+     *
+     * Ex: Host machine is not attached to serial port of GPSDO
+     * and can therefore not query the GPSDO for the PPS edge.
+     *
+     * This is a 3-step process, and will take at most 3 seconds to complete.
+     * Upon completion, the times will be synchronized to the time provided.
+     *
+     * - Step1: set the time at the next pps (potential race condition)
+     * - Step2: wait for the seconds to rollover to catch the pps edge
+     * - Step3: set the time at the next pps (synchronous for all boards)
+     *
+     * \param time_spec the time to latch into the usrp device
+     */
+    virtual void set_time_unknown_pps(const time_spec_t &time_spec) = 0;
+
+    /*!
+     * Are the times across all motherboards in this configuration synchronized?
+     * Checks that all time registers are approximately close but not exact,
+     * given that the RTT may varying for a control packet transaction.
+     * \return true when all motherboards time registers are in sync
+     */
+    virtual bool get_time_synchronized(void) = 0;
+
+    /*!
+     * Issue a stream command to the usrp device.
+     * This tells the usrp to send samples into the host.
+     * See the documentation for stream_cmd_t for more info.
+     * \param stream_cmd the stream command to issue
+     */
+    virtual void issue_stream_cmd(const stream_cmd_t &stream_cmd) = 0;
+
+    /*!
+     * Set the clock configuration for the usrp device.
+     * This tells the usrp how to get a 10Mhz reference and PPS clock.
+     * See the documentation for clock_config_t for more info.
+     * \param clock_config the clock configuration to set
+     * \param mboard which motherboard to set the config
+     */
+    virtual void set_clock_config(const clock_config_t &clock_config, size_t mboard) = 0;
+
+    /*!
+     * Get the number of USRP motherboards in this configuration.
+     */
+    virtual size_t get_num_mboards(void) = 0;
+
+    /*******************************************************************
+     * RX methods
+     ******************************************************************/
+    /*!
+     * Set the RX subdevice specification:
+     * The subdev spec maps a physical part of a daughter-board to a channel number.
+     * Set the subdev spec before calling into any methods with a channel number.
+     * The subdev spec must be the same size across all motherboards.
+     * \param spec the new subdevice specification
+     * \param mboard the motherboard index 0 to M-1
+     */
+    virtual void set_rx_subdev_spec(const uhd::usrp::subdev_spec_t &spec, size_t mboard) = 0;
+
+    /*!
+     * Get the RX subdevice specification.
+     * \param mboard the motherboard index 0 to M-1
+     * \return the subdevice specification in use
+     */
+    virtual uhd::usrp::subdev_spec_t get_rx_subdev_spec(size_t mboard) = 0;
+
+    /*!
+     * Get the number of RX channels in this configuration.
+     * This is the number of USRPs times the number of RX channels per board,
+     * where the number of RX channels per board is homogeneous among all USRPs.
+     */
+    virtual size_t get_rx_num_channels(void) = 0;
+
+    /*!
+     * Get the name of the RX subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the subdevice name
+     */
+    virtual std::string get_rx_subdev_name(size_t chan) = 0;
+
+    /*!
+     * Set the RX sample rate across all channels.
+     * \param rate the rate in Sps
+     */
+    virtual void set_rx_rate(double rate) = 0;
+
+    /*!
+     * Gets the RX sample rate for all channels.
+     * \return the rate in Sps
+     */
+    virtual double get_rx_rate(void) = 0;
+
+    /*!
+     * Set the RX center frequency.
+     * \param tune_request tune request instructions
+     * \param chan the channel index 0 to N-1
+     * \return a tune result object
+     */
+    virtual tune_result_t set_rx_freq(
+        const tune_request_t &tune_request, size_t chan = 0
+    ) = 0;
+
+    /*!
+     * Get the RX center frequency.
+     * \param chan the channel index 0 to N-1
+     * \return the frequency in Hz
+     */
+    virtual double get_rx_freq(size_t chan) = 0;
+
+    /*!
+     * Get the RX center frequency range.
+     * \param chan the channel index 0 to N-1
+     * \return a frequency range object
+     */
+    virtual freq_range_t get_rx_freq_range(size_t chan) = 0;
+
+    /*!
+     * Set the RX gain value for the specified gain element.
+     * For an empty name, distribute across all gain elements.
+     * \param gain the gain in dB
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_rx_gain(float gain, const std::string &name, size_t chan) = 0;
+
+    //! A convenience wrapper for setting overall RX gain
+    void set_rx_gain(float gain, size_t chan){
+        return this->set_rx_gain(gain, ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the RX gain value for the specified gain element.
+     * For an empty name, sum across all gain elements.
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     * \return the gain in dB
+     */
+    virtual float get_rx_gain(const std::string &name, size_t chan) = 0;
+
+    //! A convenience wrapper for getting overall RX gain
+    float get_rx_gain(size_t chan){
+        return this->get_rx_gain(ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the RX gain range for the specified gain element.
+     * For an empty name, calculate the overall gain range.
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     * \return a gain range object
+     */
+    virtual gain_range_t get_rx_gain_range(const std::string &name, size_t chan) = 0;
+
+    //! A convenience wrapper for getting overall RX gain range
+    gain_range_t get_rx_gain_range(size_t chan){
+        return this->get_rx_gain_range(ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the names of the gain elements in the RX chain.
+     * Gain elements are ordered from antenna to FPGA.
+     * \param chan the channel index 0 to N-1
+     * \return a vector of gain element names
+     */
+    virtual std::vector<std::string> get_rx_gain_names(size_t chan) = 0;
+
+    /*!
+     * Select the RX antenna on the subdevice.
+     * \param ant the antenna name
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_rx_antenna(const std::string &ant, size_t chan) = 0;
+
+    /*!
+     * Get the selected RX antenna on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the antenna name
+     */
+    virtual std::string get_rx_antenna(size_t chan) = 0;
+
+    /*!
+     * Get a list of possible RX antennas on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return a vector of antenna names
+     */
+    virtual std::vector<std::string> get_rx_antennas(size_t chan) = 0;
+
+    /*!
+     * Get the locked status of the LO on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return true for locked
+     */
+    virtual bool get_rx_lo_locked(size_t chan) = 0;
+
+    /*!
+     * Set the RX bandwidth on the subdevice.
+     * \param bandwidth the bandwidth in Hz
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_rx_bandwidth(double bandwidth, size_t chan) = 0;
+
+    /*!
+     * Get the RX bandwidth on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the bandwidth in Hz
+     */
+    virtual double get_rx_bandwidth(size_t chan) = 0;
+
+    /*!
+     * Read the RSSI value on the RX subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the rssi in dB
+     * \throw exception if RSSI readback not supported
+     */
+    virtual float read_rssi(size_t chan) = 0;
+
+    /*!
+     * Get the dboard interface object for the RX subdevice.
+     * The dboard interface gives access to GPIOs, SPI, I2C, low-speed ADC and DAC.
+     * Use at your own risk!
+     * \param chan the channel index 0 to N-1
+     * \return the dboard interface sptr
+     */
+    virtual dboard_iface::sptr get_rx_dboard_iface(size_t chan) = 0;
+
+    /*******************************************************************
+     * TX methods
+     ******************************************************************/
+    /*!
+     * Set the TX subdevice specification:
+     * The subdev spec maps a physical part of a daughter-board to a channel number.
+     * Set the subdev spec before calling into any methods with a channel number.
+     * The subdev spec must be the same size across all motherboards.
+     * \param spec the new subdevice specification
+     * \param mboard the motherboard index 0 to M-1
+     */
+    virtual void set_tx_subdev_spec(const uhd::usrp::subdev_spec_t &spec, size_t mboard) = 0;
+
+    /*!
+     * Get the TX subdevice specification.
+     * \param mboard the motherboard index 0 to M-1
+     * \return the subdevice specification in use
+     */
+    virtual uhd::usrp::subdev_spec_t get_tx_subdev_spec(size_t mboard) = 0;
+
+    /*!
+     * Get the number of TX channels in this configuration.
+     * This is the number of USRPs times the number of TX channels per board,
+     * where the number of TX channels per board is homogeneous among all USRPs.
+     */
+    virtual size_t get_tx_num_channels(void) = 0;
+
+    /*!
+     * Get the name of the TX subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the subdevice name
+     */
+    virtual std::string get_tx_subdev_name(size_t chan) = 0;
+
+    /*!
+     * Set the TX sample rate across all channels.
+     * \param rate the rate in Sps
+     */
+    virtual void set_tx_rate(double rate) = 0;
+
+    /*!
+     * Gets the TX sample rate for all channels.
+     * \return the rate in Sps
+     */
+    virtual double get_tx_rate(void) = 0;
+
+    /*!
+     * Set the TX center frequency.
+     * \param tune_request tune request instructions
+     * \param chan the channel index 0 to N-1
+     * \return a tune result object
+     */
+    virtual tune_result_t set_tx_freq(
+        const tune_request_t &tune_request, size_t chan = 0
+    ) = 0;
+
+    /*!
+     * Get the TX center frequency.
+     * \param chan the channel index 0 to N-1
+     * \return the frequency in Hz
+     */
+    virtual double get_tx_freq(size_t chan) = 0;
+
+    /*!
+     * Get the TX center frequency range.
+     * \param chan the channel index 0 to N-1
+     * \return a frequency range object
+     */
+    virtual freq_range_t get_tx_freq_range(size_t chan) = 0;
+
+    /*!
+     * Set the TX gain value for the specified gain element.
+     * For an empty name, distribute across all gain elements.
+     * \param gain the gain in dB
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_tx_gain(float gain, const std::string &name, size_t chan) = 0;
+
+    //! A convenience wrapper for setting overall TX gain
+    void set_tx_gain(float gain, size_t chan){
+        return this->set_tx_gain(gain, ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the TX gain value for the specified gain element.
+     * For an empty name, sum across all gain elements.
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     * \return the gain in dB
+     */
+    virtual float get_tx_gain(const std::string &name, size_t chan) = 0;
+
+    //! A convenience wrapper for getting overall TX gain
+    float get_tx_gain(size_t chan){
+        return this->get_tx_gain(ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the TX gain range for the specified gain element.
+     * For an empty name, calculate the overall gain range.
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     * \return a gain range object
+     */
+    virtual gain_range_t get_tx_gain_range(const std::string &name, size_t chan) = 0;
+
+    //! A convenience wrapper for getting overall TX gain range
+    gain_range_t get_tx_gain_range(size_t chan){
+        return this->get_tx_gain_range(ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the names of the gain elements in the TX chain.
+     * Gain elements are ordered from antenna to FPGA.
+     * \param chan the channel index 0 to N-1
+     * \return a vector of gain element names
+     */
+    virtual std::vector<std::string> get_tx_gain_names(size_t chan) = 0;
+
+    /*!
+     * Select the TX antenna on the subdevice.
+     * \param ant the antenna name
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_tx_antenna(const std::string &ant, size_t chan) = 0;
+
+    /*!
+     * Get the selected TX antenna on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the antenna name
+     */
+    virtual std::string get_tx_antenna(size_t chan) = 0;
+
+    /*!
+     * Get a list of possible TX antennas on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return a vector of antenna names
+     */
+    virtual std::vector<std::string> get_tx_antennas(size_t chan) = 0;
+
+    /*!
+     * Get the locked status of the LO on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return true for locked
+     */
+    virtual bool get_tx_lo_locked(size_t chan) = 0;
+
+    /*!
+     * Set the TX bandwidth on the subdevice.
+     * \param bandwidth the bandwidth in Hz
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_tx_bandwidth(double bandwidth, size_t chan) = 0;
+
+    /*!
+     * Get the TX bandwidth on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the bandwidth in Hz
+     */
+    virtual double get_tx_bandwidth(size_t chan) = 0;
+
+    /*!
+     * Get the dboard interface object for the TX subdevice.
+     * The dboard interface gives access to GPIOs, SPI, I2C, low-speed ADC and DAC.
+     * Use at your own risk!
+     * \param chan the channel index 0 to N-1
+     * \return the dboard interface sptr
+     */
+    virtual dboard_iface::sptr get_tx_dboard_iface(size_t chan) = 0;
+};
+
+}}
+
+#endif /* INCLUDED_UHD_USRP_MULTI_USRP_HPP */
diff --git a/host/include/uhd/usrp/simple_usrp.hpp b/host/include/uhd/usrp/simple_usrp.hpp
index 6149f739c..77416dbbd 100644
--- a/host/include/uhd/usrp/simple_usrp.hpp
+++ b/host/include/uhd/usrp/simple_usrp.hpp
@@ -117,7 +117,7 @@ public:
     virtual double get_rx_rate(void) = 0;
 
     virtual tune_result_t set_rx_freq(double freq) = 0;
-    virtual tune_result_t set_rx_freq(double freq, double lo_off) = 0;
+    //virtual tune_result_t set_rx_freq(double freq, double lo_off) = 0;
     virtual double get_rx_freq(void) = 0;
     virtual freq_range_t get_rx_freq_range(void) = 0;
 
@@ -139,6 +139,8 @@ public:
     virtual float read_rssi(void) = 0;
 
     virtual dboard_iface::sptr get_rx_dboard_iface(void) = 0;
+    
+    virtual void set_rx_bandwidth(float) = 0;
 
     /*******************************************************************
      * TX methods
@@ -150,7 +152,7 @@ public:
     virtual double get_tx_rate(void) = 0;
 
     virtual tune_result_t set_tx_freq(double freq) = 0;
-    virtual tune_result_t set_tx_freq(double freq, double lo_off) = 0;
+    //virtual tune_result_t set_tx_freq(double freq, double lo_off) = 0;
     virtual double get_tx_freq(void) = 0;
     virtual freq_range_t get_tx_freq_range(void) = 0;
 
@@ -169,4 +171,218 @@ public:
 
 }}
 
+#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/utils/warning.hpp>
+
+namespace uhd{ namespace usrp{ namespace /*anon*/{
+
+/***********************************************************************
+ * Simple USRP Implementation
+ **********************************************************************/
+class simple_usrp_impl : public simple_usrp{
+public:
+    simple_usrp_impl(const device_addr_t &addr){
+        _sdev = single_usrp::make(addr);
+    }
+
+    ~simple_usrp_impl(void){
+        /* NOP */
+    }
+
+    device::sptr get_device(void){
+        return _sdev->get_device();
+    }
+
+    std::string get_pp_string(void){
+        return _sdev->get_pp_string();
+    }
+
+    /*******************************************************************
+     * Misc
+     ******************************************************************/
+    time_spec_t get_time_now(void){
+        return _sdev->get_time_now();
+    }
+
+    void set_time_now(const time_spec_t &time_spec){
+        return _sdev->set_time_now(time_spec);
+    }
+
+    void set_time_next_pps(const time_spec_t &time_spec){
+        return _sdev->set_time_next_pps(time_spec);
+    }
+
+    void issue_stream_cmd(const stream_cmd_t &stream_cmd){
+        return _sdev->issue_stream_cmd(stream_cmd);
+    }
+
+    void set_clock_config(const clock_config_t &clock_config){
+        return _sdev->set_clock_config(clock_config);
+    }
+
+    /*******************************************************************
+     * RX methods
+     ******************************************************************/
+    void set_rx_subdev_spec(const subdev_spec_t &spec){
+        return _sdev->set_rx_subdev_spec(spec);
+    }
+
+    subdev_spec_t get_rx_subdev_spec(void){
+        return _sdev->get_rx_subdev_spec();
+    }
+
+    void set_rx_rate(double rate){
+        return _sdev->set_rx_rate(rate);
+    }
+
+    double get_rx_rate(void){
+        return _sdev->get_rx_rate();
+    }
+
+    tune_result_t set_rx_freq(double target_freq){
+        return _sdev->set_rx_freq(target_freq);
+    }
+
+    //tune_result_t set_rx_freq(double target_freq, double lo_off){
+    //    return _sdev->set_rx_freq(target_freq, lo_off);
+    //}
+
+    double get_rx_freq(void){
+        return _sdev->get_rx_freq();
+    }
+
+    freq_range_t get_rx_freq_range(void){
+        return _sdev->get_rx_freq_range();
+    }
+
+    void set_rx_gain(float gain){
+        return _sdev->set_rx_gain(gain);
+    }
+
+    float get_rx_gain(void){
+        return _sdev->get_rx_gain();
+    }
+
+    gain_range_t get_rx_gain_range(void){
+        return _sdev->get_rx_gain_range();
+    }
+
+    void set_rx_antenna(const std::string &ant){
+        return _sdev->set_rx_antenna(ant);
+    }
+
+    std::string get_rx_antenna(void){
+        return _sdev->get_rx_antenna();
+    }
+
+    std::vector<std::string> get_rx_antennas(void){
+        return _sdev->get_rx_antennas();
+    }
+
+    bool get_rx_lo_locked(void){
+        return _sdev->get_rx_lo_locked();
+    }
+
+    float read_rssi(void){
+        return _sdev->read_rssi();
+    }
+
+    dboard_iface::sptr get_rx_dboard_iface(void){
+        return _sdev->get_rx_dboard_iface();
+    }
+    
+    void set_rx_bandwidth(float bandwidth) {
+        return _sdev->set_rx_bandwidth(bandwidth);
+    }
+
+    /*******************************************************************
+     * TX methods
+     ******************************************************************/
+    void set_tx_subdev_spec(const subdev_spec_t &spec){
+        return _sdev->set_tx_subdev_spec(spec);
+    }
+
+    subdev_spec_t get_tx_subdev_spec(void){
+        return _sdev->get_tx_subdev_spec();
+    }
+
+    void set_tx_rate(double rate){
+        return _sdev->set_tx_rate(rate);
+    }
+
+    double get_tx_rate(void){
+        return _sdev->get_tx_rate();
+    }
+
+    tune_result_t set_tx_freq(double target_freq){
+        return _sdev->set_tx_freq(target_freq);
+    }
+
+    //tune_result_t set_tx_freq(double target_freq, double lo_off){
+    //    return _sdev->set_tx_freq(target_freq, lo_off);
+    //}
+
+    double get_tx_freq(void){
+        return _sdev->get_tx_freq();
+    }
+
+    freq_range_t get_tx_freq_range(void){
+        return _sdev->get_tx_freq_range();
+    }
+
+    void set_tx_gain(float gain){
+        return _sdev->set_tx_gain(gain);
+    }
+
+    float get_tx_gain(void){
+        return _sdev->get_tx_gain();
+    }
+
+    gain_range_t get_tx_gain_range(void){
+        return _sdev->get_tx_gain_range();
+    }
+
+    void set_tx_antenna(const std::string &ant){
+        return _sdev->set_tx_antenna(ant);
+    }
+
+    std::string get_tx_antenna(void){
+        return _sdev->get_tx_antenna();
+    }
+
+    std::vector<std::string> get_tx_antennas(void){
+        return _sdev->get_tx_antennas();
+    }
+
+    bool get_tx_lo_locked(void){
+        return _sdev->get_tx_lo_locked();
+    }
+
+    dboard_iface::sptr get_tx_dboard_iface(void){
+        return _sdev->get_tx_dboard_iface();
+    }
+
+private:
+    single_usrp::sptr _sdev;
+};
+
+}}}
+
+namespace uhd{ namespace usrp{
+
+/***********************************************************************
+ * The Make Function
+ **********************************************************************/
+inline simple_usrp::sptr simple_usrp::make(const device_addr_t &dev_addr){
+    uhd::warning::post(
+        "The simple USRP interface has been deprecated.\n"
+        "Please switch to the single USRP interface.\n"
+        "#include <uhd/usrp/single_usrp.hpp>\n"
+        "single_usrp::sptr sdev = single_usrp::make(args);\n"
+    );
+    return sptr(new simple_usrp_impl(dev_addr));
+}
+
+}}
+
 #endif /* INCLUDED_UHD_USRP_SIMPLE_USRP_HPP */
diff --git a/host/include/uhd/usrp/single_usrp.hpp b/host/include/uhd/usrp/single_usrp.hpp
index 1b89a3620..26303fe10 100644
--- a/host/include/uhd/usrp/single_usrp.hpp
+++ b/host/include/uhd/usrp/single_usrp.hpp
@@ -23,6 +23,7 @@
 #include <uhd/types/ranges.hpp>
 #include <uhd/types/stream_cmd.hpp>
 #include <uhd/types/clock_config.hpp>
+#include <uhd/types/tune_request.hpp>
 #include <uhd/types/tune_result.hpp>
 #include <uhd/usrp/subdev_spec.hpp>
 #include <uhd/usrp/dboard_iface.hpp>
@@ -33,8 +34,8 @@
 namespace uhd{ namespace usrp{
 
 /*!
- * The single USRP device class:
- * A single usrp facilitates ease-of-use for most use-case scenarios.
+ * The single-USRP device class:
+ * A single-USRP facilitates ease-of-use for most use-case scenarios.
  * The wrapper provides convenience functions to tune the devices
  * as well as to set the dboard gains, antennas, and other properties.
  * This wrapper supports multi-channel configurations per motherboard.
@@ -43,6 +44,9 @@ class UHD_API single_usrp : boost::noncopyable{
 public:
     typedef boost::shared_ptr<single_usrp> sptr;
 
+    //! A wildcard gain element name
+    static const std::string ALL_GAINS;
+
     /*!
      * Make a new single usrp from the device address.
      * \param dev_addr the device address
@@ -57,15 +61,21 @@ public:
      */
     virtual device::sptr get_device(void) = 0;
 
+    /*******************************************************************
+     * Mboard methods
+     ******************************************************************/
     /*!
-     * Get a printable name for this usrp.
+     * Get a printable summary for this USRP configuration.
      * \return a printable string
      */
     virtual std::string get_pp_string(void) = 0;
 
-    /*******************************************************************
-     * Misc
-     ******************************************************************/
+    /*!
+     * Get canonical name for this USRP motherboard.
+     * \return a string representing the name
+     */
+    virtual std::string get_mboard_name(void) = 0;
+
     /*!
      * Gets the current time in the usrp time registers.
      * \return a timespec representing current usrp time
@@ -110,60 +120,331 @@ public:
     /*******************************************************************
      * RX methods
      ******************************************************************/
+    /*!
+     * Set the RX subdevice specification:
+     * The subdev spec maps a physical part of a daughter-board to a channel number.
+     * Set the subdev spec before calling into any methods with a channel number.
+     * \param spec the new subdevice specification
+     */
     virtual void set_rx_subdev_spec(const uhd::usrp::subdev_spec_t &spec) = 0;
+
+    /*!
+     * Get the RX subdevice specification.
+     * \return the subdevice specification in use
+     */
     virtual uhd::usrp::subdev_spec_t get_rx_subdev_spec(void) = 0;
 
+    /*!
+     * Get the name of the RX subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the subdevice name
+     */
+    virtual std::string get_rx_subdev_name(size_t chan = 0) = 0;
+
+    /*!
+     * Set the RX sample rate across all channels.
+     * \param rate the rate in Sps
+     */
     virtual void set_rx_rate(double rate) = 0;
+
+    /*!
+     * Gets the RX sample rate for all channels.
+     * \return the rate in Sps
+     */
     virtual double get_rx_rate(void) = 0;
 
-    virtual tune_result_t set_rx_freq(double freq, size_t chan = 0) = 0;
-    virtual tune_result_t set_rx_freq(double freq, double lo_off, size_t chan = 0) = 0;
+    /*!
+     * Set the RX center frequency.
+     * \param tune_request tune request instructions
+     * \param chan the channel index 0 to N-1
+     * \return a tune result object
+     */
+    virtual tune_result_t set_rx_freq(
+        const tune_request_t &tune_request, size_t chan = 0
+    ) = 0;
+
+    /*!
+     * Get the RX center frequency.
+     * \param chan the channel index 0 to N-1
+     * \return the frequency in Hz
+     */
     virtual double get_rx_freq(size_t chan = 0) = 0;
+
+    /*!
+     * Get the RX center frequency range.
+     * \param chan the channel index 0 to N-1
+     * \return a frequency range object
+     */
     virtual freq_range_t get_rx_freq_range(size_t chan = 0) = 0;
 
-    virtual void set_rx_gain(float gain, size_t chan = 0) = 0;
-    virtual float get_rx_gain(size_t chan = 0) = 0;
-    virtual gain_range_t get_rx_gain_range(size_t chan = 0) = 0;
+    /*!
+     * Set the RX gain value for the specified gain element.
+     * For an empty name, distribute across all gain elements.
+     * \param gain the gain in dB
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_rx_gain(float gain, const std::string &name, size_t chan = 0) = 0;
+
+    //! A convenience wrapper for setting overall RX gain
+    void set_rx_gain(float gain, size_t chan = 0){
+        return this->set_rx_gain(gain, ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the RX gain value for the specified gain element.
+     * For an empty name, sum across all gain elements.
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     * \return the gain in dB
+     */
+    virtual float get_rx_gain(const std::string &name, size_t chan = 0) = 0;
+
+    //! A convenience wrapper for getting overall RX gain
+    float get_rx_gain(size_t chan = 0){
+        return this->get_rx_gain(ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the RX gain range for the specified gain element.
+     * For an empty name, calculate the overall gain range.
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     * \return a gain range object
+     */
+    virtual gain_range_t get_rx_gain_range(const std::string &name, size_t chan = 0) = 0;
+
+    //! A convenience wrapper for getting overall RX gain range
+    gain_range_t get_rx_gain_range(size_t chan = 0){
+        return this->get_rx_gain_range(ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the names of the gain elements in the RX chain.
+     * Gain elements are ordered from antenna to FPGA.
+     * \param chan the channel index 0 to N-1
+     * \return a vector of gain element names
+     */
+    virtual std::vector<std::string> get_rx_gain_names(size_t chan = 0) = 0;
 
+    /*!
+     * Select the RX antenna on the subdevice.
+     * \param ant the antenna name
+     * \param chan the channel index 0 to N-1
+     */
     virtual void set_rx_antenna(const std::string &ant, size_t chan = 0) = 0;
+
+    /*!
+     * Get the selected RX antenna on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the antenna name
+     */
     virtual std::string get_rx_antenna(size_t chan = 0) = 0;
+
+    /*!
+     * Get a list of possible RX antennas on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return a vector of antenna names
+     */
     virtual std::vector<std::string> get_rx_antennas(size_t chan = 0) = 0;
 
+    /*!
+     * Get the locked status of the LO on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return true for locked
+     */
     virtual bool get_rx_lo_locked(size_t chan = 0) = 0;
 
     /*!
-     * Read the RSSI value from a usrp device.
-     * Or throw if the dboard does not support an RSSI readback.
+     * Set the RX bandwidth on the subdevice.
+     * \param bandwidth the bandwidth in Hz
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_rx_bandwidth(double bandwidth, size_t chan = 0) = 0;
+
+    /*!
+     * Get the RX bandwidth on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the bandwidth in Hz
+     */
+    virtual double get_rx_bandwidth(size_t chan = 0) = 0;
+
+    /*!
+     * Read the RSSI value on the RX subdevice.
+     * \param chan the channel index 0 to N-1
      * \return the rssi in dB
+     * \throw exception if RSSI readback not supported
      */
     virtual float read_rssi(size_t chan = 0) = 0;
 
+    /*!
+     * Get the dboard interface object for the RX subdevice.
+     * The dboard interface gives access to GPIOs, SPI, I2C, low-speed ADC and DAC.
+     * Use at your own risk!
+     * \param chan the channel index 0 to N-1
+     * \return the dboard interface sptr
+     */
     virtual dboard_iface::sptr get_rx_dboard_iface(size_t chan = 0) = 0;
 
     /*******************************************************************
      * TX methods
      ******************************************************************/
+    /*!
+     * Set the TX subdevice specification:
+     * The subdev spec maps a physical part of a daughter-board to a channel number.
+     * Set the subdev spec before calling into any methods with a channel number.
+     * \param spec the new subdevice specification
+     */
     virtual void set_tx_subdev_spec(const uhd::usrp::subdev_spec_t &spec) = 0;
+
+    /*!
+     * Get the TX subdevice specification.
+     * \return the subdevice specification in use
+     */
     virtual uhd::usrp::subdev_spec_t get_tx_subdev_spec(void) = 0;
 
+    /*!
+     * Get the name of the TX subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the subdevice name
+     */
+    virtual std::string get_tx_subdev_name(size_t chan = 0) = 0;
+
+    /*!
+     * Set the TX sample rate across all channels.
+     * \param rate the rate in Sps
+     */
     virtual void set_tx_rate(double rate) = 0;
+
+    /*!
+     * Gets the TX sample rate for all channels.
+     * \return the rate in Sps
+     */
     virtual double get_tx_rate(void) = 0;
 
-    virtual tune_result_t set_tx_freq(double freq, size_t chan = 0) = 0;
-    virtual tune_result_t set_tx_freq(double freq, double lo_off, size_t chan = 0) = 0;
+    /*!
+     * Set the TX center frequency.
+     * \param tune_request tune request instructions
+     * \param chan the channel index 0 to N-1
+     * \return a tune result object
+     */
+    virtual tune_result_t set_tx_freq(
+        const tune_request_t &tune_request, size_t chan = 0
+    ) = 0;
+
+    /*!
+     * Get the TX center frequency.
+     * \param chan the channel index 0 to N-1
+     * \return the frequency in Hz
+     */
     virtual double get_tx_freq(size_t chan = 0) = 0;
+
+    /*!
+     * Get the TX center frequency range.
+     * \param chan the channel index 0 to N-1
+     * \return a frequency range object
+     */
     virtual freq_range_t get_tx_freq_range(size_t chan = 0) = 0;
 
-    virtual void set_tx_gain(float gain, size_t chan = 0) = 0;
-    virtual float get_tx_gain(size_t chan = 0) = 0;
-    virtual gain_range_t get_tx_gain_range(size_t chan = 0) = 0;
+    /*!
+     * Set the TX gain value for the specified gain element.
+     * For an empty name, distribute across all gain elements.
+     * \param gain the gain in dB
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_tx_gain(float gain, const std::string &name, size_t chan = 0) = 0;
+
+    //! A convenience wrapper for setting overall TX gain
+    void set_tx_gain(float gain, size_t chan = 0){
+        return this->set_tx_gain(gain, ALL_GAINS, chan);
+    }
 
+    /*!
+     * Get the TX gain value for the specified gain element.
+     * For an empty name, sum across all gain elements.
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     * \return the gain in dB
+     */
+    virtual float get_tx_gain(const std::string &name, size_t chan = 0) = 0;
+
+    //! A convenience wrapper for getting overall TX gain
+    float get_tx_gain(size_t chan = 0){
+        return this->get_tx_gain(ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the TX gain range for the specified gain element.
+     * For an empty name, calculate the overall gain range.
+     * \param name the name of the gain element
+     * \param chan the channel index 0 to N-1
+     * \return a gain range object
+     */
+    virtual gain_range_t get_tx_gain_range(const std::string &name, size_t chan = 0) = 0;
+
+    //! A convenience wrapper for getting overall TX gain range
+    gain_range_t get_tx_gain_range(size_t chan = 0){
+        return this->get_tx_gain_range(ALL_GAINS, chan);
+    }
+
+    /*!
+     * Get the names of the gain elements in the TX chain.
+     * Gain elements are ordered from antenna to FPGA.
+     * \param chan the channel index 0 to N-1
+     * \return a vector of gain element names
+     */
+    virtual std::vector<std::string> get_tx_gain_names(size_t chan = 0) = 0;
+
+    /*!
+     * Select the TX antenna on the subdevice.
+     * \param ant the antenna name
+     * \param chan the channel index 0 to N-1
+     */
     virtual void set_tx_antenna(const std::string &ant, size_t chan = 0) = 0;
+
+    /*!
+     * Get the selected TX antenna on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the antenna name
+     */
     virtual std::string get_tx_antenna(size_t chan = 0) = 0;
+
+    /*!
+     * Get a list of possible TX antennas on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return a vector of antenna names
+     */
     virtual std::vector<std::string> get_tx_antennas(size_t chan = 0) = 0;
 
+    /*!
+     * Get the locked status of the LO on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return true for locked
+     */
     virtual bool get_tx_lo_locked(size_t chan = 0) = 0;
 
+    /*!
+     * Set the TX bandwidth on the subdevice.
+     * \param bandwidth the bandwidth in Hz
+     * \param chan the channel index 0 to N-1
+     */
+    virtual void set_tx_bandwidth(double bandwidth, size_t chan = 0) = 0;
+
+    /*!
+     * Get the TX bandwidth on the subdevice.
+     * \param chan the channel index 0 to N-1
+     * \return the bandwidth in Hz
+     */
+    virtual double get_tx_bandwidth(size_t chan = 0) = 0;
+
+    /*!
+     * Get the dboard interface object for the TX subdevice.
+     * The dboard interface gives access to GPIOs, SPI, I2C, low-speed ADC and DAC.
+     * Use at your own risk!
+     * \param chan the channel index 0 to N-1
+     * \return the dboard interface sptr
+     */
     virtual dboard_iface::sptr get_tx_dboard_iface(size_t chan = 0) = 0;
 };
 
diff --git a/host/include/uhd/usrp/subdev_props.hpp b/host/include/uhd/usrp/subdev_props.hpp
index cd07cb7a8..8f096ffe4 100644
--- a/host/include/uhd/usrp/subdev_props.hpp
+++ b/host/include/uhd/usrp/subdev_props.hpp
@@ -53,6 +53,7 @@ namespace uhd{ namespace usrp{
         SUBDEV_PROP_ANTENNA_NAMES     = 'A', //ro, prop_names_t
         SUBDEV_PROP_LO_LOCKED         = 'L', //ro, bool
         SUBDEV_PROP_CONNECTION        = 'c', //ro, subdev_conn_t
+        SUBDEV_PROP_ENABLED           = 'e', //rw, bool
         SUBDEV_PROP_USE_LO_OFFSET     = 'l', //ro, bool
         SUBDEV_PROP_RSSI              = 'R', //ro, float
         SUBDEV_PROP_BANDWIDTH         = 'B'  //rw, double
diff --git a/host/include/uhd/usrp/subdev_spec.hpp b/host/include/uhd/usrp/subdev_spec.hpp
index 2f32509b9..b189724c9 100644
--- a/host/include/uhd/usrp/subdev_spec.hpp
+++ b/host/include/uhd/usrp/subdev_spec.hpp
@@ -19,16 +19,17 @@
 #define INCLUDED_UHD_USRP_SUBDEV_SPEC_HPP
 
 #include <uhd/config.hpp>
+#include <boost/operators.hpp>
 #include <vector>
 #include <string>
 
 namespace uhd{ namespace usrp{
 
     /*!
-     * A subdevice specification (daughterboard, subdevice) name pairing.
+     * A subdevice specification (daughterboard slot, subdevice) name pairing.
      */
-    struct UHD_API subdev_spec_pair_t{
-        //! The daughterboard name
+    struct UHD_API subdev_spec_pair_t : boost::equality_comparable<subdev_spec_pair_t>{
+        //! The daughterboard slot name
         std::string db_name;
 
         //! The subdevice name
@@ -45,8 +46,11 @@ namespace uhd{ namespace usrp{
         );
     };
 
+    //! overloaded comparison operator for subdev_spec_pair_t
+    UHD_API bool operator==(const subdev_spec_pair_t &, const subdev_spec_pair_t &);
+
     /*!
-     * A list of (daughterboard name, subdevice name) pairs:
+     * A list of (daughterboard slot name, subdevice name) pairs:
      *
      * A subdevice specification represents a list of subdevices on a motherboard.
      * The subdevices specified may span across multiple daughterboards;
@@ -58,6 +62,11 @@ namespace uhd{ namespace usrp{
      * The markup-string is a whitespace separated list of dboard:subdev pairs.
      * The first pair represents the subdevice for channel zero,
      * the second pair represents the subdevice for channel one, and so on.
+     *
+     * Special handling for empty conditions:
+     * - An empty subdevice specification means: select the first subdevice found in the configuration
+     * - An empty daughterboard name means: select the only daughterboard slot or error if multiple exist
+     * - An empty subdevice name means: select the only subdevice on that board or error if multiple exist
      */
     class UHD_API subdev_spec_t : public std::vector<subdev_spec_pair_t>{
     public:
diff --git a/host/include/uhd/usrp/tune_helper.hpp b/host/include/uhd/usrp/tune_helper.hpp
index ec133fa08..db12241c1 100644
--- a/host/include/uhd/usrp/tune_helper.hpp
+++ b/host/include/uhd/usrp/tune_helper.hpp
@@ -20,6 +20,7 @@
 
 #include <uhd/config.hpp>
 #include <uhd/wax.hpp>
+#include <uhd/types/tune_request.hpp>
 #include <uhd/types/tune_result.hpp>
 
 namespace uhd{ namespace usrp{
@@ -32,23 +33,12 @@ namespace uhd{ namespace usrp{
      * \param subdev the dboard subdevice object with properties
      * \param ddc the mboard dsp object with properties
      * \param chan the channel of the dsp to tune
-     * \param target_freq the desired center frequency
-     * \param lo_offset an offset for the subdevice IF from center
+     * \param tune_request tune request instructions
      * \return a tune result struct
      */
     UHD_API tune_result_t tune_rx_subdev_and_dsp(
         wax::obj subdev, wax::obj ddc, size_t chan,
-        double target_freq, double lo_offset
-    );
-
-    /*!
-     * Tune a rx chain to the desired frequency:
-     * Same as the above, except the LO offset
-     * is calculated based on the subdevice and BW.
-     */
-    UHD_API tune_result_t tune_rx_subdev_and_dsp(
-        wax::obj subdev, wax::obj ddc,
-        size_t chan, double target_freq
+        const tune_request_t &tune_request
     );
 
     /*!
@@ -70,23 +60,12 @@ namespace uhd{ namespace usrp{
      * \param subdev the dboard subdevice object with properties
      * \param duc the mboard dsp object with properties
      * \param chan the channel of the dsp to tune
-     * \param target_freq the desired center frequency
-     * \param lo_offset an offset for the subdevice IF from center
+     * \param tune_request tune request instructions
      * \return a tune result struct
      */
     UHD_API tune_result_t tune_tx_subdev_and_dsp(
         wax::obj subdev, wax::obj duc, size_t chan,
-        double target_freq, double lo_offset
-    );
-
-    /*!
-     * Tune a tx chain to the desired frequency:
-     * Same as the above, except the LO offset
-     * is calculated based on the subdevice and BW.
-     */
-    UHD_API tune_result_t tune_tx_subdev_and_dsp(
-        wax::obj subdev, wax::obj duc,
-        size_t chan, double target_freq
+        const tune_request_t &tune_request
     );
 
     /*!
diff --git a/host/include/uhd/utils/gain_group.hpp b/host/include/uhd/utils/gain_group.hpp
index 3955dfa9a..c863248ce 100644
--- a/host/include/uhd/utils/gain_group.hpp
+++ b/host/include/uhd/utils/gain_group.hpp
@@ -23,6 +23,8 @@
 #include <boost/shared_ptr.hpp>
 #include <boost/function.hpp>
 #include <boost/utility.hpp>
+#include <vector>
+#include <string>
 
 namespace uhd{
 
@@ -40,36 +42,57 @@ public:
     typedef boost::shared_ptr<gain_group> sptr;
 
     /*!
-     * Get the overall gain range for this group.
+     * Get the gain range for the gain element specified by name.
+     * For an empty name, get the overall gain range for this group.
      * Overall step is defined as the minimum step size.
+     * \param name name of the gain element (optional)
      * \return a gain range with overall min, max, step
      */
-    virtual gain_range_t get_range(void) = 0;
+    virtual gain_range_t get_range(const std::string &name = "") = 0;
 
     /*!
-     * Get the overall gain value for this group.
-     * \return a summation of all the gain values
+     * Get the gain value for the gain element specified by name.
+     * For an empty name, get the overall gain value for this group.
+     * \param name name of the gain element (optional)
+     * \return a gain value of the element or all elements
      */
-    virtual float get_value(void) = 0;
+    virtual float get_value(const std::string &name = "") = 0;
 
     /*!
-     * Set the overall gain value for this group.
+     * Set the gain value for the gain element specified by name.
+     * For an empty name, set the overall gain value for this group.
      * The power will be distributed across individual gain elements.
      * The semantics of how to do this are determined by the priority.
-     * \param gain the gain to set across the group
+     * \param gain the gain to set for the lement or across the group
+     * \param name name of the gain element (optional)
      */
-    virtual void set_value(float gain) = 0;
+    virtual void set_value(float gain, const std::string &name = "") = 0;
 
     /*!
-     * Register a set of gain functions into this group.
+     * Get a list of names of registered gain elements.
+     * The names are in the order that they were registered.
+     * \return a vector of gain name strings
+     */
+    virtual const std::vector<std::string> get_names(void) = 0;
+
+    /*!
+     * Register a set of gain functions into this group:
+     *
+     * The name should be a unique and non-empty name.
+     * Othwerwise, the implementation will rename it.
+     *
      * Priority determines how power will be distributed
      * with higher priorities getting the power first,
      * and lower priorities getting the remainder power.
+     *
+     * \param name the name of the gain element
      * \param gain_fcns the set of gain functions
      * \param priority the priority of the gain element
      */
     virtual void register_fcns(
-        const gain_fcns_t &gain_fcns, size_t priority = 0
+        const std::string &name,
+        const gain_fcns_t &gain_fcns,
+        size_t priority = 0
     ) = 0;
 
     /*!
diff --git a/host/include/uhd/utils/warning.hpp b/host/include/uhd/utils/warning.hpp
index 91d8400ab..a1e3f0d1e 100644
--- a/host/include/uhd/utils/warning.hpp
+++ b/host/include/uhd/utils/warning.hpp
@@ -19,16 +19,44 @@
 #define INCLUDED_UHD_UTILS_WARNING_HPP
 
 #include <uhd/config.hpp>
+#include <boost/function.hpp>
+#include <vector>
 #include <string>
 
-namespace uhd{
+namespace uhd{ namespace warning{
+
+    //! Callback function type for a message handler
+    typedef boost::function<void(std::string)> handler_t;
 
     /*!
-     * Print a formatted warning string to stderr.
+     * Post a warning message to all registered handlers.
      * \param msg the multiline warning message
      */
-    UHD_API void print_warning(const std::string &msg);
+    UHD_API void post(const std::string &msg);
+
+    /*!
+     * Register a new handler with this name.
+     * If the name was already registered for this name,
+     * the old registered handler will be replaced.
+     * \param name a unique name for this handler
+     * \param handler the callback handler function
+     */
+    UHD_API void register_handler(const std::string &name, const handler_t &handler);
+
+    /*!
+     * Unregister a handler for this name.
+     * \param name a unique name for a registered handler
+     * \return the handler that was registered
+     * \throw error when the name was not found in the registry
+     */
+    UHD_API handler_t unregister_handler(const std::string &name);
+
+    /*!
+     * Get a list of registered handler names.
+     * \return a vector of unique string names
+     */
+    UHD_API const std::vector<std::string> registry_names(void);
 
-} //namespace uhd
+}} //namespace uhd::warning
 
 #endif /* INCLUDED_UHD_UTILS_WARNING_HPP */
diff --git a/host/lib/device.cpp b/host/lib/device.cpp
index d575ebaab..386588a08 100644
--- a/host/lib/device.cpp
+++ b/host/lib/device.cpp
@@ -26,6 +26,7 @@
 #include <boost/functional/hash.hpp>
 #include <boost/tuple/tuple.hpp>
 #include <stdexcept>
+#include <iostream>
 
 using namespace uhd;
 
@@ -73,12 +74,17 @@ device_addrs_t device::find(const device_addr_t &hint){
     device_addrs_t device_addrs;
 
     BOOST_FOREACH(const dev_fcn_reg_t &fcn, get_dev_fcn_regs()){
-        device_addrs_t discovered_addrs = fcn.get<0>()(hint);
-        device_addrs.insert(
-            device_addrs.begin(),
-            discovered_addrs.begin(),
-            discovered_addrs.end()
-        );
+        try{
+            device_addrs_t discovered_addrs = fcn.get<0>()(hint);
+            device_addrs.insert(
+                device_addrs.begin(),
+                discovered_addrs.begin(),
+                discovered_addrs.end()
+            );
+        }
+        catch(const std::exception &e){
+            std::cerr << "Device discovery error: " << e.what() << std::endl;
+        }
     }
 
     return device_addrs;
diff --git a/host/lib/ic_reg_maps/CMakeLists.txt b/host/lib/ic_reg_maps/CMakeLists.txt
index f8e15c13d..25f34a280 100644
--- a/host/lib/ic_reg_maps/CMakeLists.txt
+++ b/host/lib/ic_reg_maps/CMakeLists.txt
@@ -68,3 +68,8 @@ LIBUHD_PYTHON_GEN_SOURCE(
     ${CMAKE_SOURCE_DIR}/lib/ic_reg_maps/gen_ad9522_regs.py
     ${CMAKE_BINARY_DIR}/lib/ic_reg_maps/ad9522_regs.hpp
 )
+
+LIBUHD_PYTHON_GEN_SOURCE(
+    ${CMAKE_SOURCE_DIR}/lib/ic_reg_maps/gen_tuner_4937di5_regs.py
+    ${CMAKE_BINARY_DIR}/lib/ic_reg_maps/tuner_4937di5_regs.hpp
+)
diff --git a/host/lib/ic_reg_maps/gen_max2118_regs.py b/host/lib/ic_reg_maps/gen_max2118_regs.py
index 506fbaec8..506fbaec8 100644..100755
--- a/host/lib/ic_reg_maps/gen_max2118_regs.py
+++ b/host/lib/ic_reg_maps/gen_max2118_regs.py
diff --git a/host/lib/ic_reg_maps/gen_tuner_4937di5_regs.py b/host/lib/ic_reg_maps/gen_tuner_4937di5_regs.py
new file mode 100644
index 000000000..73f7aa3db
--- /dev/null
+++ b/host/lib/ic_reg_maps/gen_tuner_4937di5_regs.py
@@ -0,0 +1,75 @@
+#!/usr/bin/env python
+#
+# Copyright 2010 Ettus Research LLC
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+########################################################################
+# Template for raw text data describing registers
+# name addr[bit range inclusive] default optional enums
+########################################################################
+REGS_TMPL="""\
+########################################################################
+## Note: offsets given from perspective of data bits (excludes address)
+########################################################################
+## Divider byte 1
+########################################################################
+db1                   0[0:6]        0x00
+########################################################################
+## Divider byte 2
+########################################################################
+db2                   1[0:7]        0x00
+########################################################################
+## Control byte 1
+########################################################################
+cb7                   2[7]          0x01
+cp                    2[6]          0x00     low,high
+os                    2[0]          0x00     on,off
+rs                    2[1:2]        0x00     d512=3,d640=0,d1024=1
+test                  2[3:5]        0x01     normal=0x01,cpoff=0x02,cpsink=0x06,cpsrc=0x07,cptest1=0x04,cptest2=0x05
+########################################################################
+## Control byte 2
+########################################################################
+bandsel               3[4:7]        0x03     uhf=0x03,vhfhi=0x09,vhflo=0x0a
+power                 3[3]          0x00     on,off
+"""
+
+########################################################################
+# Template for methods in the body of the struct
+########################################################################
+BODY_TMPL="""\
+boost::uint8_t get_reg(boost::uint8_t addr){
+    boost::uint8_t reg = 0;
+    switch(addr){
+    #for $addr in sorted(set(map(lambda r: r.get_addr(), $regs)))
+    case $addr:
+        #for $reg in filter(lambda r: r.get_addr() == addr, $regs)
+        reg |= (boost::uint8_t($reg.get_name()) & $reg.get_mask()) << $reg.get_shift();
+        #end for
+        break;
+    #end for
+    }
+    return boost::uint8_t(reg);
+}
+
+"""
+
+if __name__ == '__main__':
+    import common; common.generate(
+        name='tuner_4937di5_regs',
+        regs_tmpl=REGS_TMPL,
+        body_tmpl=BODY_TMPL,
+        file=__file__,
+    )
diff --git a/host/lib/transport/CMakeLists.txt b/host/lib/transport/CMakeLists.txt
index 62c4f62b1..b95d46381 100644
--- a/host/lib/transport/CMakeLists.txt
+++ b/host/lib/transport/CMakeLists.txt
@@ -31,12 +31,15 @@ IF(LIBUSB_FOUND)
         ${CMAKE_SOURCE_DIR}/lib/transport/libusb1_zero_copy.cpp
         ${CMAKE_SOURCE_DIR}/lib/transport/libusb1_base.cpp
         ${CMAKE_SOURCE_DIR}/lib/transport/libusb1_base.hpp
-        ${CMAKE_SOURCE_DIR}/lib/transport/libusb1_device_handle.cpp
     )
-    IF(WIN32) #include our custom stdint for libusb
-	INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/lib/transport/include)
-    ENDIF(WIN32)
+    IF(MSVC) #include our custom stdint for libusb
+        INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/lib/transport/msvc)
+    ENDIF(MSVC)
     SET(HAVE_USB_SUPPORT TRUE)
+ELSE(LIBUSB_FOUND)
+    LIBUHD_APPEND_SOURCES(
+        ${CMAKE_SOURCE_DIR}/lib/transport/usb_dummy_impl.cpp
+    )
 ENDIF(LIBUSB_FOUND)
 
 IF(HAVE_USB_SUPPORT)
diff --git a/host/lib/transport/libusb1_base.cpp b/host/lib/transport/libusb1_base.cpp
index 1f816c6e2..cfa77d9ca 100644
--- a/host/lib/transport/libusb1_base.cpp
+++ b/host/lib/transport/libusb1_base.cpp
@@ -17,110 +17,249 @@
 
 #include "libusb1_base.hpp"
 #include <uhd/utils/assert.hpp>
+#include <uhd/types/dict.hpp>
+#include <boost/weak_ptr.hpp>
+#include <boost/foreach.hpp>
 #include <iostream>
 
+using namespace uhd;
 using namespace uhd::transport;
 
-/**********************************************************
- * Helper Methods
- **********************************************************/
+/***********************************************************************
+ * libusb session
+ **********************************************************************/
+class libusb_session_impl : public libusb::session{
+public:
+    libusb_session_impl(void){
+        UHD_ASSERT_THROW(libusb_init(&_context) == 0);
+        libusb_set_debug(_context, debug_level);
+    }
+
+    ~libusb_session_impl(void){
+        libusb_exit(_context);
+    }
+
+    libusb_context *get_context(void) const{
+        return _context;
+    }
+
+private:
+    libusb_context *_context;
+};
+
+libusb::session::sptr libusb::session::get_global_session(void){
+    static boost::weak_ptr<session> global_session;
 
-/**********************************************************
- * libusb namespace 
- **********************************************************/
-void libusb::init(libusb_context **ctx, int debug_level)
-{
-    if (libusb_init(ctx) < 0)
-        std::cerr << "error: libusb_init" << std::endl;
+    //not expired -> get existing session
+    if (not global_session.expired()) return global_session.lock();
 
-    libusb_set_debug(*ctx, debug_level);
+    //create a new global session
+    sptr new_global_session(new libusb_session_impl());
+    global_session = new_global_session;
+    return new_global_session;
 }
 
-libusb_device_handle *libusb::open_device(libusb_context *ctx,
-                                          usb_device_handle::sptr handle)
-{
-    libusb_device_handle *dev_handle = NULL;
-    libusb_device **libusb_dev_list;
-    size_t dev_cnt = libusb_get_device_list(ctx, &libusb_dev_list);
-
-    //find and open the USB device 
-    for (size_t i = 0; i < dev_cnt; i++) {
-        libusb_device *dev = libusb_dev_list[i];
-
-        if (compare_device(dev, handle)) {
-            libusb_open(dev, &dev_handle);
-            libusb_unref_device(dev);
-            break;
-        }
-            
-        libusb_unref_device(dev);
+/***********************************************************************
+ * libusb device
+ **********************************************************************/
+class libusb_device_impl : public libusb::device{
+public:
+    libusb_device_impl(libusb_device *dev){
+        _session = libusb::session::get_global_session();
+        _dev = dev;
     }
 
-    return dev_handle;
-}
+    ~libusb_device_impl(void){
+        libusb_unref_device(this->get());
+    }
+
+    libusb_device *get(void) const{
+        return _dev;
+    }
+
+private:
+    libusb::session::sptr _session; //always keep a reference to session
+    libusb_device *_dev;
+};
+
+/***********************************************************************
+ * libusb device list
+ **********************************************************************/
+class libusb_device_list_impl : public libusb::device_list{
+public:
+    libusb_device_list_impl(void){
+        libusb::session::sptr sess = libusb::session::get_global_session();
 
-//note: changed order of checks so it only tries to get_serial and get_device_address if vid and pid match
-//doing this so it doesn't try to open the device if it's not ours
-bool libusb::compare_device(libusb_device *dev,
-                            usb_device_handle::sptr handle)
-{
-    std::string serial         = handle->get_serial();
-    boost::uint16_t vendor_id  = handle->get_vendor_id();
-    boost::uint16_t product_id = handle->get_product_id();
-    boost::uint16_t device_addr = handle->get_device_addr();
-
-    libusb_device_descriptor libusb_desc;
-    if (libusb_get_device_descriptor(dev, &libusb_desc) < 0)
-        return false;
-    if (vendor_id != libusb_desc.idVendor)
-        return false;
-    if (product_id != libusb_desc.idProduct)
-        return false; 
-    if (serial != get_serial(dev))
-        return false;
-    if (device_addr != libusb_get_device_address(dev))
-        return false;
-
-    return true;
+        //allocate a new list of devices
+        libusb_device** dev_list;
+        ssize_t ret = libusb_get_device_list(sess->get_context(), &dev_list);
+        if (ret < 0) throw std::runtime_error("cannot enumerate usb devices");
+
+        //fill the vector of device references
+        for (size_t i = 0; i < size_t(ret); i++) _devs.push_back(
+            libusb::device::sptr(new libusb_device_impl(dev_list[i]))
+        );
+
+        //free the device list but dont unref (done in ~device)
+        libusb_free_device_list(dev_list, false/*dont unref*/);
+    }
+
+    size_t size(void) const{
+        return _devs.size();
+    }
+
+    libusb::device::sptr at(size_t i) const{
+        return _devs.at(i);
+    }
+
+private:
+    std::vector<libusb::device::sptr> _devs;
+};
+
+libusb::device_list::sptr libusb::device_list::make(void){
+    return sptr(new libusb_device_list_impl());
 }
 
+/***********************************************************************
+ * libusb device descriptor
+ **********************************************************************/
+class libusb_device_descriptor_impl : public libusb::device_descriptor{
+public:
+    libusb_device_descriptor_impl(libusb::device::sptr dev){
+        _dev = dev;
+        UHD_ASSERT_THROW(libusb_get_device_descriptor(_dev->get(), &_desc) == 0);
+    }
 
-bool libusb::open_interface(libusb_device_handle *dev_handle,
-                            int interface)
-{
-    int ret = libusb_claim_interface(dev_handle, interface);
-    if (ret < 0) {
-        std::cerr << "error: libusb_claim_interface() " << ret << std::endl;
-        return false;
+    const libusb_device_descriptor &get(void) const{
+        return _desc;
     }
-    else {
-        return true;
+
+    std::string get_ascii_serial(void) const{
+        if (this->get().iSerialNumber == 0) return "";
+
+        libusb::device_handle::sptr handle(
+            libusb::device_handle::get_cached_handle(_dev)
+        );
+
+        unsigned char buff[512];
+        ssize_t ret = libusb_get_string_descriptor_ascii(
+            handle->get(), this->get().iSerialNumber, buff, sizeof(buff)
+        );
+        if (ret < 0) return ""; //on error, just return empty string
+
+        return std::string((char *)buff, ret);
     }
+
+private:
+    libusb::device::sptr _dev; //always keep a reference to device
+    libusb_device_descriptor _desc;
+};
+
+libusb::device_descriptor::sptr libusb::device_descriptor::make(device::sptr dev){
+    return sptr(new libusb_device_descriptor_impl(dev));
 }
 
+/***********************************************************************
+ * libusb device handle
+ **********************************************************************/
+class libusb_device_handle_impl : public libusb::device_handle{
+public:
+    libusb_device_handle_impl(libusb::device::sptr dev){
+        _dev = dev;
+        UHD_ASSERT_THROW(libusb_open(_dev->get(), &_handle) == 0);
+    }
+
+    ~libusb_device_handle_impl(void){
+        //release all claimed interfaces
+        for (size_t i = 0; i < _claimed.size(); i++){
+            libusb_release_interface(this->get(), _claimed[i]);
+        }
+        libusb_close(_handle);
+    }
+
+    libusb_device_handle *get(void) const{
+        return _handle;
+    }
+
+    void claim_interface(int interface){
+        UHD_ASSERT_THROW(libusb_claim_interface(this->get(), interface) == 0);
+        _claimed.push_back(interface);
+    }
+
+private:
+    libusb::device::sptr _dev; //always keep a reference to device
+    libusb_device_handle *_handle;
+    std::vector<int> _claimed;
+};
+
+libusb::device_handle::sptr libusb::device_handle::get_cached_handle(device::sptr dev){
+    static uhd::dict<libusb_device *, boost::weak_ptr<device_handle> > handles;
+
+    //not expired -> get existing handle
+    if (handles.has_key(dev->get()) and not handles[dev->get()].expired()){
+        return handles[dev->get()].lock();
+    }
+
+    //create a new cached handle
+    try{
+        sptr new_handle(new libusb_device_handle_impl(dev));
+        handles[dev->get()] = new_handle;
+        return new_handle;
+    }
+    catch(const std::exception &e){
+        std::cerr << "USB open failed: see the application notes for your device." << std::endl;
+        throw std::runtime_error(e.what());
+    }
+}
 
-std::string libusb::get_serial(libusb_device *dev)
-{
-    unsigned char buff[32];
+/***********************************************************************
+ * libusb special handle
+ **********************************************************************/
+class libusb_special_handle_impl : public libusb::special_handle{
+public:
+    libusb_special_handle_impl(libusb::device::sptr dev){
+        _dev = dev;
+    }
 
-    libusb_device_descriptor desc;
-    if (libusb_get_device_descriptor(dev, &desc) < 0)
-        return "";
+    libusb::device::sptr get_device(void) const{
+        return _dev;
+    }
 
-    if (desc.iSerialNumber == 0)
-        return "";
+    std::string get_serial(void) const{
+        return libusb::device_descriptor::make(this->get_device())->get_ascii_serial();
+    }
 
-    //open the device because we have to
-    libusb_device_handle *dev_handle;
-    if (libusb_open(dev, &dev_handle) < 0)
-        return "";
+    boost::uint16_t get_vendor_id(void) const{
+        return libusb::device_descriptor::make(this->get_device())->get().idVendor;
+    }
 
-    if (libusb_get_string_descriptor_ascii(dev_handle, desc.iSerialNumber,
-                                           buff, sizeof(buff)) < 0) {
-        return "";
+    boost::uint16_t get_product_id(void) const{
+        return libusb::device_descriptor::make(this->get_device())->get().idProduct;
     }
 
-    libusb_close(dev_handle);
+private:
+    libusb::device::sptr _dev; //always keep a reference to device
+};
+
+libusb::special_handle::sptr libusb::special_handle::make(device::sptr dev){
+    return sptr(new libusb_special_handle_impl(dev));
+}
+
+/***********************************************************************
+ * list device handles implementations
+ **********************************************************************/
+std::vector<usb_device_handle::sptr> usb_device_handle::get_device_list(
+    boost::uint16_t vid, boost::uint16_t pid
+){
+    std::vector<usb_device_handle::sptr> handles;
+
+    libusb::device_list::sptr dev_list = libusb::device_list::make();
+    for (size_t i = 0; i < dev_list->size(); i++){
+        usb_device_handle::sptr handle = libusb::special_handle::make(dev_list->at(i));
+        if (handle->get_vendor_id() == vid and handle->get_product_id() == pid){
+            handles.push_back(handle);
+        }
+    }
 
-    return (char*) buff;
+    return handles;
 }
diff --git a/host/lib/transport/libusb1_base.hpp b/host/lib/transport/libusb1_base.hpp
index 484bcf3d9..04c1d6574 100644
--- a/host/lib/transport/libusb1_base.hpp
+++ b/host/lib/transport/libusb1_base.hpp
@@ -19,74 +19,129 @@
 #define INCLUDED_LIBUHD_TRANSPORT_LIBUSB_HPP
 
 #include <uhd/config.hpp>
+#include <boost/utility.hpp>
+#include <boost/shared_ptr.hpp>
 #include <uhd/transport/usb_device_handle.hpp>
-#include <libusb-1.0/libusb.h>
+#include <libusb.h>
 
+/***********************************************************************
+ * Libusb object oriented smart pointer wrappers:
+ * The following wrappers provide allocation and automatic deallocation
+ * for various libusb data types and handles. The construction routines
+ * also store tables of already allocated structures to avoid multiple
+ * occurrences of opened handles (for example).
+ **********************************************************************/
 namespace uhd { namespace transport {
 
 namespace libusb {
-    /*
-     * Initialize libusb and set debug level
-     * Takes a pointer to context pointer because that's
-     * how libusb rolls. Debug levels.
-     *     
-     *   Level 0: no messages ever printed by the library (default)
-     *   Level 1: error messages are printed to stderr
-     *   Level 2: warning and error messages are printed to stderr
-     *   Level 3: informational messages are printed to stdout, warning
-     *            and error messages are printed to stderr
-     *
-     * \param ctx pointer to context pointer
-     * \param debug_level
+
+    /*!
+     * This session class holds a global libusb context for this process.
+     * The get global session call will create a new context if none exists.
+     * When all references to session are destroyed, the context will be freed.
      */
-    void init(libusb_context **ctx, int debug_level);
-
-    /*
-     * Open the device specified by a generic handle
-     * Find the libusb_device cooresponding to the generic handle
-     * and open it for I/O, which returns a libusb_device_handle
-     * ready for an interface
-     * \param ctx the libusb context used for init
-     * \return a libusb_device_handle ready for action 
+    class session : boost::noncopyable {
+    public:
+        typedef boost::shared_ptr<session> sptr;
+
+        /*!
+         *   Level 0: no messages ever printed by the library (default)
+         *   Level 1: error messages are printed to stderr
+         *   Level 2: warning and error messages are printed to stderr
+         *   Level 3: informational messages are printed to stdout, warning
+         *            and error messages are printed to stderr
+         */
+        static const int debug_level = 0;
+
+        //! get a shared pointer to the global session
+        static sptr get_global_session(void);
+
+        //! get the underlying libusb context pointer
+        virtual libusb_context *get_context(void) const = 0;
+    };
+
+    /*!
+     * Holds a device pointer with a reference to the session.
      */
-    libusb_device_handle *open_device(libusb_context *ctx,
-                                      usb_device_handle::sptr handle);
-
-    /*
-     * Compare a libusb device with a generic handle 
-     * Check the descriptors and open the device to check the
-     * serial number string. Compare values against the given
-     * handle. The libusb context is already implied in the
-     * libusb_device.
-     * \param dev a libusb_device pointer
-     * \param handle a generic handle specifier
-     * \return true if handle and device match, false otherwise
+    class device : boost::noncopyable {
+    public:
+        typedef boost::shared_ptr<device> sptr;
+
+        //! get the underlying device pointer
+        virtual libusb_device *get(void) const = 0;
+    };
+
+    /*!
+     * This device list class holds a device list that will be
+     * automatically freed when the last reference is destroyed.
      */
-    bool compare_device(libusb_device *dev, usb_device_handle::sptr handle);
-
-    /*
-     * Open an interface to the device
-     * This is a logical operation for operating system housekeeping as
-     * nothing is sent over the bus. The interface much correspond
-     * to the USB device descriptors.
-     * \param dev_handle libusb handle to an opened device
-     * \param interface integer of the interface to use
-     * \return true on success, false on error
+    class device_list : boost::noncopyable {
+    public:
+        typedef boost::shared_ptr<device_list> sptr;
+
+        //! make a new device list
+        static sptr make(void);
+
+        //! the number of devices in this list
+        virtual size_t size() const = 0;
+
+        //! get the device pointer at a particular index
+        virtual device::sptr at(size_t index) const = 0;
+    };
+
+    /*!
+     * Holds a device descriptor and a reference to the device.
      */
-    bool open_interface(libusb_device_handle *dev_handle, int interface);
-
-    /*
-     * Get serial number 
-     * The standard USB device descriptor contains an index to an
-     * actual serial number string descriptor. The index is readily
-     * readble, but the string descriptor requires probing the device.
-     * Because this call attempts to open the device, it may not
-     * succeed because not all USB devices are readily opened.
-     * The default language is used for the request (English).
-     * \param dev a libusb_device pointer
-     * \return string serial number or 0 on error or unavailablity
+    class device_descriptor : boost::noncopyable {
+    public:
+        typedef boost::shared_ptr<device_descriptor> sptr;
+
+        //! make a new descriptor from a device reference
+        static sptr make(device::sptr);
+
+        //! get the underlying device descriptor
+        virtual const libusb_device_descriptor &get(void) const = 0;
+
+        virtual std::string get_ascii_serial(void) const = 0;
+    };
+
+    /*!
+     * Holds a device handle and a reference to the device.
      */
-    std::string get_serial(libusb_device *dev);
+    class device_handle : boost::noncopyable {
+    public:
+        typedef boost::shared_ptr<device_handle> sptr;
+
+        //! get a cached handle or make a new one given the device
+        static sptr get_cached_handle(device::sptr);
+
+        //! get the underlying device handle
+        virtual libusb_device_handle *get(void) const = 0;
+
+        /*!
+         * Open USB interfaces for control using magic value
+         * IN interface:      2
+         * OUT interface:     1
+         * Control interface: 0
+         */
+        virtual void claim_interface(int) = 0;
+    };
+
+    /*!
+     * The special handle is our internal implementation of the
+     * usb device handle which is used publicly to identify a device.
+     */
+    class special_handle : public usb_device_handle {
+    public:
+        typedef boost::shared_ptr<special_handle> sptr;
+
+        //! make a new special handle from device
+        static sptr make(device::sptr);
+
+        //! get the underlying device reference
+        virtual device::sptr get_device(void) const = 0;
+    };
+
 }
 
 }} //namespace
diff --git a/host/lib/transport/libusb1_control.cpp b/host/lib/transport/libusb1_control.cpp
index 3531128b2..f903907d0 100644
--- a/host/lib/transport/libusb1_control.cpp
+++ b/host/lib/transport/libusb1_control.cpp
@@ -20,7 +20,6 @@
 
 using namespace uhd::transport;
 
-const int libusb_debug_level = 0;
 const int libusb_timeout = 0;
 
 /***********************************************************************
@@ -28,68 +27,38 @@ const int libusb_timeout = 0;
  **********************************************************************/
 class libusb_control_impl : public usb_control {
 public:
-    libusb_control_impl(usb_device_handle::sptr handle);
-    ~libusb_control_impl();
+    libusb_control_impl(libusb::device_handle::sptr handle):
+        _handle(handle)
+    {
+        _handle->claim_interface(0 /* control interface */);
+    }
 
-    size_t submit(boost::uint8_t request_type,
+    ssize_t submit(boost::uint8_t request_type,
                   boost::uint8_t request,
                   boost::uint16_t value,
                   boost::uint16_t index,
                   unsigned char *buff,
-                  boost::uint16_t length); 
+                  boost::uint16_t length
+    ){
+        return libusb_control_transfer(_handle->get(),
+                                       request_type,
+                                       request,
+                                       value,
+                                       index,
+                                       buff,
+                                       length,
+                                       libusb_timeout);
+    }
 
 private:
-    libusb_context       *_ctx;
-    libusb_device_handle *_dev_handle;
+    libusb::device_handle::sptr _handle;
 };
 
-
-libusb_control_impl::libusb_control_impl(usb_device_handle::sptr handle)
-{
-    libusb::init(&_ctx, libusb_debug_level);
-
-    // Find and open the libusb_device corresponding to the
-    // given handle and return the libusb_device_handle
-    // that can be used for I/O purposes.
-    _dev_handle = libusb::open_device(_ctx, handle);
-
-    // Open USB interfaces for control using magic value
-    // IN interface:      2
-    // OUT interface:     1
-    // Control interface: 0
-    libusb::open_interface(_dev_handle, 0);
-}
-
-
-libusb_control_impl::~libusb_control_impl()
-{
-    libusb_close(_dev_handle);
-    libusb_exit(_ctx);
-}
-
-
-size_t libusb_control_impl::submit(boost::uint8_t request_type,
-                                   boost::uint8_t request,
-                                   boost::uint16_t value,
-                                   boost::uint16_t index, 
-                                   unsigned char *buff,
-                                   boost::uint16_t length) 
-{
-    return libusb_control_transfer(_dev_handle,
-                                   request_type,
-                                   request,
-                                   value,
-                                   index,
-                                   buff, 
-                                   length, 
-                                   libusb_timeout);
-}
-
-
 /***********************************************************************
  * USB control public make functions
  **********************************************************************/
-usb_control::sptr usb_control::make(usb_device_handle::sptr handle)
-{
-    return sptr(new libusb_control_impl(handle));
+usb_control::sptr usb_control::make(usb_device_handle::sptr handle){
+    return sptr(new libusb_control_impl(libusb::device_handle::get_cached_handle(
+        boost::static_pointer_cast<libusb::special_handle>(handle)->get_device()
+    )));
 }
diff --git a/host/lib/transport/libusb1_device_handle.cpp b/host/lib/transport/libusb1_device_handle.cpp
deleted file mode 100644
index 7efddd410..000000000
--- a/host/lib/transport/libusb1_device_handle.cpp
+++ /dev/null
@@ -1,117 +0,0 @@
-//
-// Copyright 2010 Ettus Research LLC
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-
-#include "libusb1_base.hpp"
-#include <uhd/utils/assert.hpp>
-#include <iostream>
-
-using namespace uhd::transport;
-
-const int libusb_debug_level = 0;
-
-/****************************************************************
- * libusb USB device handle implementation class
- ***************************************************************/
-class libusb1_device_handle_impl : public usb_device_handle {
-public:
-    libusb1_device_handle_impl(std::string serial,
-                               boost::uint16_t product_id,
-                               boost::uint16_t vendor_id,
-                               boost::uint16_t device_addr)
-      : _serial(serial), _product_id(product_id), 
-        _vendor_id(vendor_id), _device_addr(device_addr)
-    {
-        /* NOP */
-    }
-
-    ~libusb1_device_handle_impl()
-    {
-        /* NOP */
-    }
-
-    std::string get_serial() const
-    {
-        return _serial;
-    }
-
-    boost::uint16_t get_vendor_id() const
-    {
-        return _vendor_id;
-    }
-
-
-    boost::uint16_t get_product_id() const
-    {
-        return _product_id;
-    }
-
-    boost::uint16_t get_device_addr() const
-    {
-        return _device_addr;
-    }
-
-private:
-    std::string     _serial;
-    boost::uint16_t _product_id;
-    boost::uint16_t _vendor_id;
-    boost::uint16_t _device_addr;
-};
-
-
-usb_device_handle::sptr make_usb_device_handle(libusb_device *dev)
-{
-    libusb_device_descriptor desc;
-
-    if (libusb_get_device_descriptor(dev, &desc) < 0) {
-        UHD_ASSERT_THROW("USB: failed to get device descriptor");
-    }
-
-    std::string     serial      = libusb::get_serial(dev);
-    boost::uint16_t product_id  = desc.idProduct;
-    boost::uint16_t vendor_id   = desc.idVendor;
-    boost::uint16_t device_addr = libusb_get_device_address(dev);
-
-    return usb_device_handle::sptr(new libusb1_device_handle_impl(
-        serial,
-        product_id,
-        vendor_id,
-        device_addr));
-}
-
-std::vector<usb_device_handle::sptr> usb_device_handle::get_device_list(boost::uint16_t vid, boost::uint16_t pid)
-{
-    libusb_context *ctx = NULL;
-    libusb_device** libusb_device_list;
-    std::vector<usb_device_handle::sptr> device_handle_list;
-    libusb_device_descriptor desc;
-
-    libusb::init(&ctx, libusb_debug_level);
-
-    size_t dev_size = libusb_get_device_list(ctx, &libusb_device_list);
-    for (size_t i = 0; i < dev_size; i++) {
-        libusb_device *dev = libusb_device_list[i];
-        if(libusb_get_device_descriptor(dev, &desc) < 0) {
-          UHD_ASSERT_THROW("USB: failed to get device descriptor");
-        }
-        if(desc.idVendor == vid && desc.idProduct == pid) {
-          device_handle_list.push_back(make_usb_device_handle(dev));
-        }
-    }
-
-    libusb_exit(ctx);
-    return device_handle_list; 
-}
diff --git a/host/lib/transport/libusb1_zero_copy.cpp b/host/lib/transport/libusb1_zero_copy.cpp
index b3a160462..f589d7c77 100644
--- a/host/lib/transport/libusb1_zero_copy.cpp
+++ b/host/lib/transport/libusb1_zero_copy.cpp
@@ -17,15 +17,22 @@
 
 #include "libusb1_base.hpp"
 #include <uhd/transport/usb_zero_copy.hpp>
+#include <uhd/transport/bounded_buffer.hpp>
+#include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/assert.hpp>
-#include <boost/format.hpp>
+#include <boost/shared_array.hpp>
+#include <boost/foreach.hpp>
+#include <boost/thread.hpp>
+#include <boost/enable_shared_from_this.hpp>
+#include <vector>
 #include <iostream>
-#include <iomanip>
 
+using namespace uhd;
 using namespace uhd::transport;
 
-const int libusb_debug_level = 0;
-const int libusb_timeout = 0;
+static const double CLEANUP_TIMEOUT   = 0.2;    //seconds
+static const size_t DEFAULT_NUM_XFERS = 16;     //num xfers
+static const size_t DEFAULT_XFER_SIZE = 32*512; //bytes
 
 /***********************************************************************
  * Helper functions
@@ -53,56 +60,57 @@ void pp_transfer(libusb_transfer *lut)
  *   create a bidirectional interface. It is a zero copy implementation
  *   with respect to libusb, however, each send and recv requires a copy
  *   operation from kernel to userspace; this is due to the usbfs
- *   interface provided by the kernel. 
+ *   interface provided by the kernel.
  **********************************************************************/
 class usb_endpoint {
-private:
-    libusb_device_handle *_dev_handle;
-    libusb_context *_ctx;
-    int  _endpoint;
-    bool _input;
-
-    size_t _transfer_size;
-    size_t _num_transfers;
-
-    // Transfer state lists (transfers are free, pending, or completed)
-    std::list<libusb_transfer *>  _free_list;
-    std::list<libusb_transfer *>  _pending_list;
-    std::list<libusb_transfer *>  _completed_list;
-
-    // Calls for processing asynchronous I/O 
-    libusb_transfer *allocate_transfer(int buff_len);
-    bool cancel(libusb_transfer *lut);
-    bool cancel_all();
-    bool reap_pending_list();
-    bool reap_pending_list_timeout();
-    bool reap_completed_list();
-
-    // Transfer state manipulators 
-    void free_list_add(libusb_transfer *lut);
-    void pending_list_add(libusb_transfer *lut);
-    void completed_list_add(libusb_transfer *lut);
-    libusb_transfer *free_list_get();
-    libusb_transfer *completed_list_get();
-    bool pending_list_remove(libusb_transfer *lut);
-
-    // Debug use
-    void print_transfer_status(libusb_transfer *lut);
-
 public:
-    usb_endpoint(libusb_device_handle *dev_handle,
-                 libusb_context *ctx, int endpoint, bool input,
-                 size_t transfer_size, size_t num_transfers);
+    typedef boost::shared_ptr<usb_endpoint> sptr;
 
-    ~usb_endpoint();
+    usb_endpoint(
+        libusb::device_handle::sptr handle,
+        int endpoint,
+        bool input,
+        size_t transfer_size,
+        size_t num_transfers
+    );
+
+    ~usb_endpoint(void);
 
     // Exposed interface for submitting / retrieving transfer buffers
-    bool submit(libusb_transfer *lut);
-    libusb_transfer *get_completed_transfer();
-    libusb_transfer *get_free_transfer();
+
+    //! Submit a new transfer that was presumably just filled or emptied.
+    void submit(libusb_transfer *lut);
+
+    /*!
+     * Get an available transfer:
+     * For inputs, this is a just filled transfer.
+     * For outputs, this is a just emptied transfer.
+     * \param timeout the timeout to wait for a lut
+     * \return the transfer pointer or NULL if timeout
+     */
+    libusb_transfer *get_lut_with_wait(double timeout);
 
     //Callback use only
     void callback_handle_transfer(libusb_transfer *lut);
+
+private:
+    libusb::device_handle::sptr _handle;
+    int  _endpoint;
+    bool _input;
+
+    //! hold a bounded buffer of completed transfers
+    typedef bounded_buffer<libusb_transfer *> lut_buff_type;
+    lut_buff_type::sptr _completed_list;
+
+    //! a list of all transfer structs we allocated
+    std::vector<libusb_transfer *> _all_luts;
+
+    //! a block of memory for the transfer buffers
+    boost::shared_array<char> _buffer;
+
+    // Calls for processing asynchronous I/O
+    libusb_transfer *allocate_transfer(void *mem, size_t len);
+    void print_transfer_status(libusb_transfer *lut);
 };
 
 
@@ -115,9 +123,8 @@ public:
  * it from the pending to completed status list.
  * \param lut pointer to libusb_transfer
  */
-static void callback(libusb_transfer *lut)
-{
-    usb_endpoint *endpoint = (usb_endpoint *) lut->user_data; 
+static void callback(libusb_transfer *lut){
+    usb_endpoint *endpoint = (usb_endpoint *) lut->user_data;
     endpoint->callback_handle_transfer(lut);
 }
 
@@ -126,14 +133,9 @@ static void callback(libusb_transfer *lut)
  * Accessor call to allow list access from callback space
  * \param pointer to libusb_transfer
  */
-void usb_endpoint::callback_handle_transfer(libusb_transfer *lut)
-{
-    if (!pending_list_remove(lut)) {
-        std::cerr << "USB: pending remove failed" << std::endl;
-        return;
-    }
-
-    completed_list_add(lut);    
+void usb_endpoint::callback_handle_transfer(libusb_transfer *lut){
+    boost::this_thread::disable_interruption di; //disable because the wait can throw
+    _completed_list->push_with_wait(lut);
 }
 
 
@@ -141,21 +143,28 @@ void usb_endpoint::callback_handle_transfer(libusb_transfer *lut)
  * Constructor
  * Allocate libusb transfers and mark as free.  For IN endpoints,
  * submit the transfers so that they're ready to return when
- * data is available. 
+ * data is available.
  */
-usb_endpoint::usb_endpoint(libusb_device_handle *dev_handle,
-                          libusb_context *ctx, int endpoint, bool input,
-                          size_t transfer_size, size_t num_transfers)
-    : _dev_handle(dev_handle),
-      _ctx(ctx), _endpoint(endpoint), _input(input),
-      _transfer_size(transfer_size), _num_transfers(num_transfers)
+usb_endpoint::usb_endpoint(
+    libusb::device_handle::sptr handle,
+    int endpoint,
+    bool input,
+    size_t transfer_size,
+    size_t num_transfers
+):
+    _handle(handle),
+    _endpoint(endpoint),
+    _input(input)
 {
-    unsigned int i;
-    for (i = 0; i < _num_transfers; i++) {
-        free_list_add(allocate_transfer(_transfer_size));
+    _completed_list = lut_buff_type::make(num_transfers);
+    _buffer = boost::shared_array<char>(new char[num_transfers*transfer_size]);
+    for (size_t i = 0; i < num_transfers; i++){
+        _all_luts.push_back(allocate_transfer(_buffer.get() + i*transfer_size, transfer_size));
 
-        if (_input)
-            submit(free_list_get());
+        //input luts are immediately submitted to be filled
+        //output luts go into the completed list as free buffers
+        if (_input) this->submit(_all_luts.back());
+        else _completed_list->push_with_wait(_all_luts.back());
     }
 }
 
@@ -167,47 +176,44 @@ usb_endpoint::usb_endpoint(libusb_device_handle *dev_handle,
  * the transfers. Libusb will deallocate the data buffer held by
  * each transfer.
  */
-usb_endpoint::~usb_endpoint()
-{
-    cancel_all();
-
-    while (!_pending_list.empty()) {
-        if (!reap_pending_list())
-            std::cerr << "error: destructor failed to reap" << std::endl;
+usb_endpoint::~usb_endpoint(void){
+    //cancel all transfers
+    BOOST_FOREACH(libusb_transfer *lut, _all_luts){
+        libusb_cancel_transfer(lut);
     }
 
-    while (!_completed_list.empty()) {
-        if (!reap_completed_list())
-            std::cerr << "error: destructor failed to reap" << std::endl;
-    }
+    //collect canceled transfers (drain the queue)
+    while (this->get_lut_with_wait(CLEANUP_TIMEOUT) != NULL){};
 
-    while (!_free_list.empty()) {
-        libusb_free_transfer(free_list_get());
+    //free all transfers
+    BOOST_FOREACH(libusb_transfer *lut, _all_luts){
+        libusb_free_transfer(lut);
     }
 }
 
 
 /*
- * Allocate a libusb transfer 
+ * Allocate a libusb transfer
  * The allocated transfer - and buffer it contains - is repeatedly
  * submitted, reaped, and reused and should not be freed until shutdown.
- * \param buff_len size of the individual buffer held by each transfer
+ * \param mem a pointer to the buffer memory
+ * \param len size of the individual buffer
  * \return pointer to an allocated libusb_transfer
  */
-libusb_transfer *usb_endpoint::allocate_transfer(int buff_len)
-{
+libusb_transfer *usb_endpoint::allocate_transfer(void *mem, size_t len){
     libusb_transfer *lut = libusb_alloc_transfer(0);
-
-    unsigned char *buff = new unsigned char[buff_len];
+    UHD_ASSERT_THROW(lut != NULL);
 
     unsigned int endpoint = ((_endpoint & 0x7f) | (_input ? 0x80 : 0));
+    unsigned char *buff = reinterpret_cast<unsigned char *>(mem);
+    libusb_transfer_cb_fn lut_callback = libusb_transfer_cb_fn(&callback);
 
     libusb_fill_bulk_transfer(lut,                // transfer
-                              _dev_handle,        // dev_handle
+                              _handle->get(),     // dev_handle
                               endpoint,           // endpoint
                               buff,               // buffer
-                              buff_len,           // length
-       libusb_transfer_cb_fn(callback),           // callback
+                              len,                // length
+                              lut_callback,       // callback
                               this,               // user_data
                               0);                 // timeout
     return lut;
@@ -218,97 +224,18 @@ libusb_transfer *usb_endpoint::allocate_transfer(int buff_len)
  * Asynchonous transfer submission
  * Submit a libusb transfer to libusb add pending status
  * \param lut pointer to libusb_transfer
- * \return true on success or false on error 
- */
-bool usb_endpoint::submit(libusb_transfer *lut)
-{
-    int retval;
-    if ((retval = libusb_submit_transfer(lut)) < 0) {
-        std::cerr << "error: libusb_submit_transfer: " << retval << std::endl;
-        return false;
-    }
-
-    pending_list_add(lut);
-    return true;
-}
-
-
-/*
- * Cancel a pending transfer 
- * Search the pending list for the transfer and cancel if found.
- * \param lut pointer to libusb_transfer to cancel
- * \return true on success or false if transfer is not found
- *
- * Note: success only indicates submission of cancelation request.
- * Sucessful cancelation is not known until the callback occurs.
+ * \return true on success or false on error
  */
-bool usb_endpoint::cancel(libusb_transfer *lut)
-{
-    std::list<libusb_transfer*>::iterator iter;
-    for (iter = _pending_list.begin(); iter != _pending_list.end(); iter++) {
-        if (*iter == lut) { 
-            libusb_cancel_transfer(lut); 
-            return true;
-        }
-    }
-    return false;
+void usb_endpoint::submit(libusb_transfer *lut){
+    UHD_ASSERT_THROW(libusb_submit_transfer(lut) == 0);
 }
 
-
-/*
- * Cancel all pending transfers 
- * \return bool true if cancelation request is submitted
- *
- * Note: success only indicates submission of cancelation request.
- * Sucessful cancelation is not known until the callback occurs.
- */
-bool usb_endpoint::cancel_all()
-{
-    std::list<libusb_transfer*>::iterator iter;
-
-    for (iter = _pending_list.begin(); iter != _pending_list.end(); iter++) {
-        if (libusb_cancel_transfer(*iter) < 0) {
-            std::cerr << "error: libusb_cancal_transfer() failed" << std::endl;
-            return false;
-        }
-    }
-
-    return true;
-}
-
-
-/*
- * Reap completed transfers
- * return true if at least one transfer was reaped, false otherwise. 
- * Check completed transfers for errors and mark as free. This is a
- * blocking call. 
- * \return bool true if a libusb transfer is reaped, false otherwise
- */
-bool usb_endpoint::reap_completed_list()
-{
-    libusb_transfer *lut;
-
-    if (_completed_list.empty()) {
-        if (!reap_pending_list_timeout())
-            return false;
-    }
-
-    while (!_completed_list.empty()) {
-        lut = completed_list_get();
-        print_transfer_status(lut);
-        free_list_add(lut);
-    }
-
-    return true;
-}
-
-
 /*
  * Print status errors of a completed transfer
  * \param lut pointer to an libusb_transfer
  */
-void usb_endpoint::print_transfer_status(libusb_transfer *lut)
-{
+void usb_endpoint::print_transfer_status(libusb_transfer *lut){
+    std::cout << "here " << lut->status << std::endl;
     switch (lut->status) {
     case LIBUSB_TRANSFER_COMPLETED:
         if (lut->actual_length < lut->length) {
@@ -344,382 +271,136 @@ void usb_endpoint::print_transfer_status(libusb_transfer *lut)
     }
 }
 
-
-/*
- * Reap pending transfers without timeout 
- * This is a blocking call. Reaping submitted transfers is
- * handled by libusb and the assigned callback function.
- * Block until at least one transfer is reaped.
- * \return true true if a transfer was reaped or false otherwise
- */
-bool usb_endpoint::reap_pending_list()
-{
-    int retval;
-
-    if ((retval = libusb_handle_events(_ctx)) < 0) {
-        std::cerr << "error: libusb_handle_events: " << retval << std::endl;
-        return false;
-    }
-
-    return true;
-}
-
-
-/*
- * Reap pending transfers with timeout 
- * This call blocks until a transfer is reaped or timeout.
- * Reaping submitted transfers is handled by libusb and the
- * assigned callback function. Block until at least one
- * transfer is reaped or timeout occurs.
- * \return true if a transfer was reaped or false otherwise
- */
-bool usb_endpoint::reap_pending_list_timeout()
-{
-    int retval;
-    timeval tv;
-
-    tv.tv_sec = 0;
-    tv.tv_usec = 100000; //100ms
-
-    size_t pending_list_size = _pending_list.size();
-
-    if ((retval = libusb_handle_events_timeout(_ctx, &tv)) < 0) {
-        std::cerr << "error: libusb_handle_events: " << retval << std::endl;
-        return false;
-    }
-
-    if (_pending_list.size() < pending_list_size) {
-        return true;
-    }
-    else {
-        return false;
-    }
-}
-
-
-/*
- * Get a free transfer
- * The transfer has an empty data bufer for OUT requests 
- * \return pointer to a libusb_transfer
- */
-libusb_transfer *usb_endpoint::get_free_transfer()
-{
-    if (_free_list.empty()) {
-        if (!reap_completed_list())
-            return NULL; 
-    }
-
-    return free_list_get();
-}
-
-
-/*
- * Get a completed transfer 
- * The transfer has a full data buffer for IN requests
- * \return pointer to libusb_transfer
- */
-libusb_transfer *usb_endpoint::get_completed_transfer()
-{
-    if (_completed_list.empty()) {
-        if (!reap_pending_list_timeout())
-            return NULL; 
-    }
-
-    return completed_list_get();
-}
-
-/*
- * List operations 
- */
-void usb_endpoint::free_list_add(libusb_transfer *lut)
-{
-    _free_list.push_back(lut);
-}
-
-void usb_endpoint::pending_list_add(libusb_transfer *lut)
-{
-    _pending_list.push_back(lut);
-}
-
-void usb_endpoint::completed_list_add(libusb_transfer *lut)
-{
-    _completed_list.push_back(lut);
-}
-
-
-/*
- * Free and completed lists don't have ordered content 
- * Pop transfers from the front as needed
- */
-libusb_transfer *usb_endpoint::free_list_get()
-{
+libusb_transfer *usb_endpoint::get_lut_with_wait(double timeout){
+    boost::this_thread::disable_interruption di; //disable because the wait can throw
     libusb_transfer *lut;
-
-    if (_free_list.size() == 0) {
-        return NULL; 
-    }
-    else { 
-        lut = _free_list.front();
-        _free_list.pop_front();
-        return lut;
-    }
+    if (_completed_list->pop_with_timed_wait(lut, timeout)) return lut;
+    return NULL;
 }
 
-
-/*
- * Free and completed lists don't have ordered content 
- * Pop transfers from the front as needed
- */
-libusb_transfer *usb_endpoint::completed_list_get()
-{
-    libusb_transfer *lut;
-
-    if (_completed_list.empty()) {
-        return NULL;
-    }
-    else { 
-        lut = _completed_list.front();
-        _completed_list.pop_front();
-        return lut;
-    }
-}
-
-
-/*
- * Search and remove transfer from pending list
- * Assuming that the callbacks occur in order, the front element
- * should yield the correct transfer. If not, then something else
- * is going on. If no transfers match, then something went wrong.
- */
-bool usb_endpoint::pending_list_remove(libusb_transfer *lut)
-{
-    std::list<libusb_transfer*>::iterator iter;
-    for (iter = _pending_list.begin(); iter != _pending_list.end(); iter++) {
-        if (*iter == lut) { 
-            _pending_list.erase(iter);
-            return true;
-        }
-    }
-    return false;
-}
-
-
 /***********************************************************************
- * Managed buffers 
+ * USB zero_copy device class
  **********************************************************************/
-/*
- * Libusb managed receive buffer
- * Construct a recv buffer from a libusb transfer. The memory held by
- * the libusb transfer is exposed through the managed buffer interface.
- * Upon destruction, the transfer and buffer are resubmitted to the
- * endpoint for further use. 
- */
-class libusb_managed_recv_buffer_impl : public managed_recv_buffer {
+class libusb_zero_copy_impl : public usb_zero_copy, public boost::enable_shared_from_this<libusb_zero_copy_impl> {
 public:
-    libusb_managed_recv_buffer_impl(libusb_transfer *lut,
-                                    usb_endpoint *endpoint)
-        : _buff(lut->buffer, lut->length)
-    {
-        _lut = lut;
-        _endpoint = endpoint;
-    }
 
-    ~libusb_managed_recv_buffer_impl()
-    {
-       if (!_endpoint->submit(_lut))
-           std::cerr << "USB: failed to submit IN transfer" << std::endl;
-    }
+    libusb_zero_copy_impl(
+        libusb::device_handle::sptr handle,
+        size_t recv_endpoint,
+        size_t send_endpoint,
+        const device_addr_t &hints
+    );
 
-private:
-    const boost::asio::const_buffer &get() const
-    {
-        return _buff; 
+    ~libusb_zero_copy_impl(void){
+        _threads_running = false;
+        _thread_group.join_all();
     }
 
-    libusb_transfer *_lut;
-    usb_endpoint *_endpoint;
-    const boost::asio::const_buffer _buff;
-};
-
-/*
- * Libusb managed send buffer
- * Construct a send buffer from a libusb transfer. The memory held by
- * the libusb transfer is exposed through the managed buffer interface.
- * Committing the buffer will set the data length and submit the buffer
- * to the endpoint. Submitting a buffer multiple times or destroying
- * the buffer before committing is an error. For the latter, the transfer
- * is returned to the endpoint with no data for reuse.
- */
-class libusb_managed_send_buffer_impl : public managed_send_buffer {
-public:
-    libusb_managed_send_buffer_impl(libusb_transfer *lut,
-                                    usb_endpoint *endpoint,
-                                    size_t buff_size)
-        : _buff(lut->buffer, buff_size), _committed(false)
-    {
-        _lut = lut;
-        _endpoint = endpoint;
-    }
+    managed_recv_buffer::sptr get_recv_buff(double);
+    managed_send_buffer::sptr get_send_buff(double);
 
-    ~libusb_managed_send_buffer_impl()
-    {
-        if (!_committed) {
-            _lut->length = 0;
-            _lut->actual_length = 0;
-            _endpoint->submit(_lut);
-        }
-    }
+    size_t get_num_recv_frames(void) const { return _num_recv_frames; }
+    size_t get_num_send_frames(void) const { return _num_send_frames; }
 
-    ssize_t commit(size_t num_bytes)
-    {
-        if (_committed) {
-            std::cerr << "UHD: send buffer already committed" << std::endl;
-            return 0;
-        }
-        
-        UHD_ASSERT_THROW(num_bytes <= boost::asio::buffer_size(_buff));
+    size_t get_recv_frame_size(void) const { return _recv_frame_size; }
+    size_t get_send_frame_size(void) const { return _send_frame_size; }
 
-        _lut->length = num_bytes;
-        _lut->actual_length = 0;
+private:
+    void release(libusb_transfer *lut){
+        _recv_ep->submit(lut);
+    }
 
-        if (_endpoint->submit(_lut)) {
-            _committed = true;
-            return num_bytes;
+    void commit(libusb_transfer *lut, size_t num_bytes){
+        lut->length = num_bytes;
+        try{
+            _send_ep->submit(lut);
         }
-        else {
-            return 0;
+        catch(const std::exception &e){
+            std::cerr << "Error in commit: " << e.what() << std::endl;
         }
     }
 
-private:
-    const boost::asio::mutable_buffer &get() const
-    {
-        return _buff; 
+    libusb::device_handle::sptr _handle;
+    const size_t _recv_frame_size, _num_recv_frames;
+    const size_t _send_frame_size, _num_send_frames;
+    usb_endpoint::sptr _recv_ep, _send_ep;
+
+    //event handler threads
+    boost::thread_group _thread_group;
+    bool _threads_running;
+
+    void run_event_loop(void){
+        set_thread_priority_safe();
+        libusb::session::sptr session = libusb::session::get_global_session();
+        _threads_running = true;
+        while(_threads_running){
+            timeval tv;
+            tv.tv_sec = 0;
+            tv.tv_usec = 100000; //100ms
+            libusb_handle_events_timeout(session->get_context(), &tv);
+        }
     }
-
-    libusb_transfer *_lut;
-    usb_endpoint *_endpoint;
-    const boost::asio::mutable_buffer _buff;
-    bool _committed;
-};
-
-
-/***********************************************************************
- * USB zero_copy device class
- **********************************************************************/
-class libusb_zero_copy_impl : public usb_zero_copy
-{
-private:
-    usb_endpoint          *_rx_ep;
-    usb_endpoint          *_tx_ep;
-
-    // Maintain libusb values
-    libusb_context       *_rx_ctx;
-    libusb_context       *_tx_ctx;
-    libusb_device_handle *_rx_dev_handle;
-    libusb_device_handle *_tx_dev_handle;
-
-    size_t _recv_buff_size;
-    size_t _send_buff_size;
-    size_t _num_frames;
-
-public:
-    typedef boost::shared_ptr<libusb_zero_copy_impl> sptr;
-
-    libusb_zero_copy_impl(usb_device_handle::sptr handle,
-                          unsigned int rx_endpoint,
-                          unsigned int tx_endpoint,
-                          size_t recv_buff_size,
-                          size_t send_buff_size);
-    
-    ~libusb_zero_copy_impl();
-
-    managed_recv_buffer::sptr get_recv_buff(void);
-    managed_send_buffer::sptr get_send_buff(void);
-
-    size_t get_num_recv_frames(void) const { return _num_frames; }
-    size_t get_num_send_frames(void) const { return _num_frames; }
 };
 
 /*
  * Constructor
  * Initializes libusb, opens devices, and sets up interfaces for I/O.
- * Finally, creates endpoints for asynchronous I/O. 
+ * Finally, creates endpoints for asynchronous I/O.
  */
-libusb_zero_copy_impl::libusb_zero_copy_impl(usb_device_handle::sptr handle,
-                                             unsigned int rx_endpoint,
-                                             unsigned int tx_endpoint,
-                                             size_t buff_size,
-                                             size_t block_size)
- : _rx_ctx(NULL), _tx_ctx(NULL), _rx_dev_handle(NULL), _tx_dev_handle(NULL),
-   _recv_buff_size(block_size), _send_buff_size(block_size),
-   _num_frames(buff_size / block_size)
+libusb_zero_copy_impl::libusb_zero_copy_impl(
+    libusb::device_handle::sptr handle,
+    size_t recv_endpoint,
+    size_t send_endpoint,
+    const device_addr_t &hints
+):
+    _handle(handle),
+    _recv_frame_size(size_t(hints.cast<double>("recv_frame_size", DEFAULT_XFER_SIZE))),
+    _num_recv_frames(size_t(hints.cast<double>("num_recv_frames", DEFAULT_NUM_XFERS))),
+    _send_frame_size(size_t(hints.cast<double>("send_frame_size", DEFAULT_XFER_SIZE))),
+    _num_send_frames(size_t(hints.cast<double>("num_send_frames", DEFAULT_NUM_XFERS)))
 {
-    // Initialize libusb with separate contexts to allow
-    // thread safe operation of transmit and receive 
-    libusb::init(&_rx_ctx, libusb_debug_level);
-    libusb::init(&_tx_ctx, libusb_debug_level);
-
-    UHD_ASSERT_THROW((_rx_ctx != NULL) && (_tx_ctx != NULL));
-
-    // Find and open the libusb_device corresponding to the
-    // given handle and return the libusb_device_handle
-    // that can be used for I/O purposes.
-    _rx_dev_handle = libusb::open_device(_rx_ctx, handle);
-    _tx_dev_handle = libusb::open_device(_tx_ctx, handle);
-
-    // Open USB interfaces for tx/rx using magic values.
-    // IN interface:      2
-    // OUT interface:     1
-    // Control interface: 0
-    libusb::open_interface(_rx_dev_handle, 2);
-    libusb::open_interface(_tx_dev_handle, 1);
-
-    _rx_ep = new usb_endpoint(_rx_dev_handle,  // libusb device_handle
-                              _rx_ctx,         // libusb context
-                              rx_endpoint,     // USB endpoint number
+    _handle->claim_interface(2 /*in interface*/);
+    _handle->claim_interface(1 /*out interface*/);
+
+    _recv_ep = usb_endpoint::sptr(new usb_endpoint(
+                              _handle,         // libusb device_handle
+                              recv_endpoint,   // USB endpoint number
                               true,            // IN endpoint
-                              _recv_buff_size, // buffer size per transfer 
-                              _num_frames);    // number of libusb transfers
+                              this->get_recv_frame_size(),  // buffer size per transfer
+                              this->get_num_recv_frames()   // number of libusb transfers
+    ));
 
-    _tx_ep = new usb_endpoint(_tx_dev_handle,  // libusb device_handle
-                              _tx_ctx,         // libusb context
-                              tx_endpoint,     // USB endpoint number
+    _send_ep = usb_endpoint::sptr(new usb_endpoint(
+                              _handle,         // libusb device_handle
+                              send_endpoint,   // USB endpoint number
                               false,           // OUT endpoint
-                              _send_buff_size, // buffer size per transfer
-                              _num_frames);    // number of libusb transfers
+                              this->get_send_frame_size(),  // buffer size per transfer
+                              this->get_num_send_frames()   // number of libusb transfers
+    ));
+
+    //spawn the event handler threads
+    size_t concurrency = hints.cast<size_t>("concurrency_hint", 1);
+    for (size_t i = 0; i < concurrency; i++) _thread_group.create_thread(
+        boost::bind(&libusb_zero_copy_impl::run_event_loop, this)
+    );
 }
 
-
-libusb_zero_copy_impl::~libusb_zero_copy_impl()
-{
-    delete _rx_ep;
-    delete _tx_ep; 
-
-    libusb_close(_rx_dev_handle);
-    libusb_close(_tx_dev_handle);
-
-    libusb_exit(_rx_ctx);
-    libusb_exit(_tx_ctx);
-}
-
-
 /*
  * Construct a managed receive buffer from a completed libusb transfer
  * (happy with buffer full of data) obtained from the receive endpoint.
  * Return empty pointer if no transfer is available (timeout or error).
- * \return pointer to a managed receive buffer 
+ * \return pointer to a managed receive buffer
  */
-managed_recv_buffer::sptr libusb_zero_copy_impl::get_recv_buff()
-{
-    libusb_transfer *lut = _rx_ep->get_completed_transfer();
+managed_recv_buffer::sptr libusb_zero_copy_impl::get_recv_buff(double timeout){
+    libusb_transfer *lut = _recv_ep->get_lut_with_wait(timeout);
     if (lut == NULL) {
         return managed_recv_buffer::sptr();
     }
     else {
-        return managed_recv_buffer::sptr(
-            new libusb_managed_recv_buffer_impl(lut,
-                                                _rx_ep));
+        return managed_recv_buffer::make_safe(
+            boost::asio::const_buffer(lut->buffer, lut->actual_length),
+            boost::bind(&libusb_zero_copy_impl::release, shared_from_this(), lut)
+        );
     }
 }
 
@@ -728,39 +409,34 @@ managed_recv_buffer::sptr libusb_zero_copy_impl::get_recv_buff()
  * Construct a managed send buffer from a free libusb transfer (with
  * empty buffer). Return empty pointer of no transfer is available
  * (timeout or error).
- * \return pointer to a managed send buffer 
+ * \return pointer to a managed send buffer
  */
-managed_send_buffer::sptr libusb_zero_copy_impl::get_send_buff()
-{
-    libusb_transfer *lut = _tx_ep->get_free_transfer();
+managed_send_buffer::sptr libusb_zero_copy_impl::get_send_buff(double timeout){
+    libusb_transfer *lut = _send_ep->get_lut_with_wait(timeout);
     if (lut == NULL) {
         return managed_send_buffer::sptr();
     }
     else {
-        return managed_send_buffer::sptr(
-            new libusb_managed_send_buffer_impl(lut,
-                                                _tx_ep,
-                                                _send_buff_size));
+        return managed_send_buffer::make_safe(
+            boost::asio::mutable_buffer(lut->buffer, this->get_send_frame_size()),
+            boost::bind(&libusb_zero_copy_impl::commit, shared_from_this(), lut, _1)
+        );
     }
 }
 
-
 /***********************************************************************
  * USB zero_copy make functions
  **********************************************************************/
-usb_zero_copy::sptr usb_zero_copy::make(usb_device_handle::sptr handle,
-                                        unsigned int rx_endpoint,
-                                        unsigned int tx_endpoint,
-                                        size_t buff_size,
-                                        size_t block_size)
-
-{
-    return sptr(new libusb_zero_copy_impl(handle,
-                                          rx_endpoint,
-                                          tx_endpoint,
-                                          buff_size, 
-                                          block_size));
+usb_zero_copy::sptr usb_zero_copy::make(
+    usb_device_handle::sptr handle,
+    size_t recv_endpoint,
+    size_t send_endpoint,
+    const device_addr_t &hints
+){
+    libusb::device_handle::sptr dev_handle(libusb::device_handle::get_cached_handle(
+        boost::static_pointer_cast<libusb::special_handle>(handle)->get_device()
+    ));
+    return sptr(new libusb_zero_copy_impl(
+        dev_handle, recv_endpoint, send_endpoint, hints
+    ));
 }
-
-
-
diff --git a/host/lib/transport/include/stdint.h b/host/lib/transport/msvc/stdint.h
index b3eb61aae..b3eb61aae 100644
--- a/host/lib/transport/include/stdint.h
+++ b/host/lib/transport/msvc/stdint.h
diff --git a/host/lib/transport/udp_zero_copy_asio.cpp b/host/lib/transport/udp_zero_copy_asio.cpp
index ee989ee2b..ed29864e9 100644
--- a/host/lib/transport/udp_zero_copy_asio.cpp
+++ b/host/lib/transport/udp_zero_copy_asio.cpp
@@ -17,25 +17,58 @@
 
 #include <uhd/transport/udp_zero_copy.hpp>
 #include <uhd/transport/udp_simple.hpp> //mtu
+#include <uhd/transport/bounded_buffer.hpp>
+#include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/assert.hpp>
 #include <uhd/utils/warning.hpp>
-#include <boost/cstdint.hpp>
+#include <boost/shared_array.hpp>
 #include <boost/asio.hpp>
 #include <boost/format.hpp>
+#include <boost/thread.hpp>
+#include <boost/enable_shared_from_this.hpp>
 #include <iostream>
 
+using namespace uhd;
 using namespace uhd::transport;
+namespace asio = boost::asio;
 
 /***********************************************************************
  * Constants
  **********************************************************************/
+//Define this to the the boost async io calls to perform receive.
+//Otherwise, get_recv_buff uses a blocking receive with timeout.
+//#define USE_ASIO_ASYNC_RECV
+
+//Define this to the the boost async io calls to perform send.
+//Otherwise, the commit callback uses a blocking send.
+//#define USE_ASIO_ASYNC_SEND
+
 //enough buffering for half a second of samples at full rate on usrp2
-static const size_t MIN_RECV_SOCK_BUFF_SIZE = size_t(sizeof(boost::uint32_t) * 25e6 * 0.5);
+static const size_t MIN_RECV_SOCK_BUFF_SIZE = size_t(4 * 25e6 * 0.5);
+
 //Large buffers cause more underflow at high rates.
 //Perhaps this is due to the kernel scheduling,
 //but may change with host-based flow control.
 static const size_t MIN_SEND_SOCK_BUFF_SIZE = size_t(10e3);
-static const double RECV_TIMEOUT = 0.1; //100 ms
+
+//The number of async frames to allocate for each send and recv:
+//The non-async recv can have a very large number of recv frames
+//because the CPU overhead is independent of the number of frames.
+#ifdef USE_ASIO_ASYNC_RECV
+static const size_t DEFAULT_NUM_RECV_FRAMES = 32;
+#else
+static const size_t DEFAULT_NUM_RECV_FRAMES = MIN_RECV_SOCK_BUFF_SIZE/udp_simple::mtu;
+#endif
+//The non-async send only ever requires a single frame
+//because the buffer will be committed before a new get.
+#ifdef USE_ASIO_ASYNC_SEND
+static const size_t DEFAULT_NUM_SEND_FRAMES = 32;
+#else
+static const size_t DEFAULT_NUM_SEND_FRAMES = MIN_SEND_SOCK_BUFF_SIZE/udp_simple::mtu;;
+#endif
+
+//a single concurrent thread for io_service seems to be the fastest
+static const size_t CONCURRENCY_HINT = 1;
 
 /***********************************************************************
  * Zero Copy UDP implementation with ASIO:
@@ -44,39 +77,68 @@ static const double RECV_TIMEOUT = 0.1; //100 ms
  *   However, it is not a true zero copy implementation as each
  *   send and recv requires a copy operation to/from userspace.
  **********************************************************************/
-class udp_zero_copy_impl:
-    public phony_zero_copy_recv_if,
-    public phony_zero_copy_send_if,
-    public udp_zero_copy
-{
+class udp_zero_copy_asio_impl : public udp_zero_copy, public boost::enable_shared_from_this<udp_zero_copy_asio_impl> {
 public:
-    typedef boost::shared_ptr<udp_zero_copy_impl> sptr;
+    typedef boost::shared_ptr<udp_zero_copy_asio_impl> sptr;
 
-    udp_zero_copy_impl(
+    udp_zero_copy_asio_impl(
         const std::string &addr,
-        const std::string &port
+        const std::string &port,
+        const device_addr_t &hints
     ):
-        phony_zero_copy_recv_if(udp_simple::mtu),
-        phony_zero_copy_send_if(udp_simple::mtu)
+        _io_service(hints.cast<size_t>("concurrency_hint", CONCURRENCY_HINT)),
+        _recv_frame_size(size_t(hints.cast<double>("recv_frame_size", udp_simple::mtu))),
+        _num_recv_frames(size_t(hints.cast<double>("num_recv_frames", DEFAULT_NUM_RECV_FRAMES))),
+        _send_frame_size(size_t(hints.cast<double>("send_frame_size", udp_simple::mtu))),
+        _num_send_frames(size_t(hints.cast<double>("num_send_frames", DEFAULT_NUM_SEND_FRAMES)))
     {
         //std::cout << boost::format("Creating udp transport for %s %s") % addr % port << std::endl;
 
-        // resolve the address
-        boost::asio::ip::udp::resolver resolver(_io_service);
-        boost::asio::ip::udp::resolver::query query(boost::asio::ip::udp::v4(), addr, port);
-        boost::asio::ip::udp::endpoint receiver_endpoint = *resolver.resolve(query);
+        //resolve the address
+        asio::ip::udp::resolver resolver(_io_service);
+        asio::ip::udp::resolver::query query(asio::ip::udp::v4(), addr, port);
+        asio::ip::udp::endpoint receiver_endpoint = *resolver.resolve(query);
 
-        // create, open, and connect the socket
-        _socket = new boost::asio::ip::udp::socket(_io_service);
-        _socket->open(boost::asio::ip::udp::v4());
+        //create, open, and connect the socket
+        _socket = new asio::ip::udp::socket(_io_service);
+        _socket->open(asio::ip::udp::v4());
         _socket->connect(receiver_endpoint);
         _sock_fd = _socket->native();
     }
 
-    ~udp_zero_copy_impl(void){
+    ~udp_zero_copy_asio_impl(void){
+        delete _work; //allow io_service run to complete
+        _thread_group.join_all(); //wait for service threads to exit
         delete _socket;
     }
 
+    void init(void){
+        //allocate all recv frames and release them to begin xfers
+        _pending_recv_buffs = pending_buffs_type::make(_num_recv_frames);
+        _recv_buffer = boost::shared_array<char>(new char[_num_recv_frames*_recv_frame_size]);
+        for (size_t i = 0; i < _num_recv_frames; i++){
+            release(_recv_buffer.get() + i*_recv_frame_size);
+        }
+
+        //allocate all send frames and push them into the fifo
+        _pending_send_buffs = pending_buffs_type::make(_num_send_frames);
+        _send_buffer = boost::shared_array<char>(new char[_num_send_frames*_send_frame_size]);
+        for (size_t i = 0; i < _num_send_frames; i++){
+            handle_send(_send_buffer.get() + i*_send_frame_size);
+        }
+
+        //spawn the service threads that will run the io service
+        _work = new asio::io_service::work(_io_service); //new work to delete later
+        for (size_t i = 0; i < CONCURRENCY_HINT; i++) _thread_group.create_thread(
+            boost::bind(&udp_zero_copy_asio_impl::service, this)
+        );
+    }
+
+    void service(void){
+        set_thread_priority_safe();
+        _io_service.run();
+    }
+
     //get size for internal socket buffer
     template <typename Opt> size_t get_buff_size(void) const{
         Opt option;
@@ -91,60 +153,165 @@ public:
         return get_buff_size<Opt>();
     }
 
+    //! handle a recv callback -> push the filled memory into the fifo
+    UHD_INLINE void handle_recv(void *mem, size_t len){
+        boost::this_thread::disable_interruption di; //disable because the wait can throw
+        _pending_recv_buffs->push_with_wait(boost::asio::buffer(mem, len));
+    }
 
-    //The number of frames is approximately the buffer size divided by the max datagram size.
-    //In reality, this is a phony zero-copy interface and the number of frames is infinite.
-    //However, its sensible to advertise a frame count that is approximate to buffer size.
-    //This way, the transport caller will have an idea about how much buffering to create.
-
-    size_t get_num_recv_frames(void) const{
-        return this->get_buff_size<boost::asio::socket_base::receive_buffer_size>()/udp_simple::mtu;
+    ////////////////////////////////////////////////////////////////////
+    #ifdef USE_ASIO_ASYNC_RECV
+    ////////////////////////////////////////////////////////////////////
+    //! pop a filled recv buffer off of the fifo and bind with the release callback
+    managed_recv_buffer::sptr get_recv_buff(double timeout){
+        boost::this_thread::disable_interruption di; //disable because the wait can throw
+        asio::mutable_buffer buff;
+        if (_pending_recv_buffs->pop_with_timed_wait(buff, timeout)){
+            return managed_recv_buffer::make_safe(
+                buff, boost::bind(
+                    &udp_zero_copy_asio_impl::release,
+                    shared_from_this(),
+                    asio::buffer_cast<void*>(buff)
+                )
+            );
+        }
+        return managed_recv_buffer::sptr();
     }
 
-    size_t get_num_send_frames(void) const{
-        return this->get_buff_size<boost::asio::socket_base::send_buffer_size>()/udp_simple::mtu;
+    //! release a recv buffer -> start an async recv on the buffer
+    void release(void *mem){
+        _socket->async_receive(
+            boost::asio::buffer(mem, this->get_recv_frame_size()),
+            boost::bind(
+                &udp_zero_copy_asio_impl::handle_recv,
+                shared_from_this(), mem,
+                asio::placeholders::bytes_transferred
+            )
+        );
     }
 
-private:
-    boost::asio::ip::udp::socket   *_socket;
-    boost::asio::io_service        _io_service;
-    int                            _sock_fd;
+    ////////////////////////////////////////////////////////////////////
+    #else /*USE_ASIO_ASYNC_RECV*/
+    ////////////////////////////////////////////////////////////////////
+    managed_recv_buffer::sptr get_recv_buff(double timeout){
+        boost::this_thread::disable_interruption di; //disable because the wait can throw
+        asio::mutable_buffer buff;
 
-    ssize_t recv(const boost::asio::mutable_buffer &buff){
         //setup timeval for timeout
         timeval tv;
         tv.tv_sec = 0;
-        tv.tv_usec = int(RECV_TIMEOUT*1e6);
+        tv.tv_usec = long(timeout*1e6);
 
         //setup rset for timeout
         fd_set rset;
         FD_ZERO(&rset);
         FD_SET(_sock_fd, &rset);
 
-        //call select to perform timed wait
-        if (::select(_sock_fd+1, &rset, NULL, NULL, &tv) <= 0) return 0;
+        //call select to perform timed wait and grab an available buffer with wait
+        //if the condition is true, call receive and return the managed buffer
+        if (
+            ::select(_sock_fd+1, &rset, NULL, NULL, &tv) > 0 and
+            _pending_recv_buffs->pop_with_timed_wait(buff, timeout)
+        ){
+            return managed_recv_buffer::make_safe(
+                asio::buffer(
+                    boost::asio::buffer_cast<void *>(buff),
+                    _socket->receive(asio::buffer(buff))
+                ),
+                boost::bind(
+                    &udp_zero_copy_asio_impl::release,
+                    shared_from_this(),
+                    asio::buffer_cast<void*>(buff)
+                )
+            );
+        }
+        return managed_recv_buffer::sptr();
+    }
+
+    void release(void *mem){
+        boost::this_thread::disable_interruption di; //disable because the wait can throw
+        handle_recv(mem, this->get_recv_frame_size());
+    }
 
-        return ::recv(
-            _sock_fd,
-            boost::asio::buffer_cast<char *>(buff),
-            boost::asio::buffer_size(buff), 0
-        );
+    ////////////////////////////////////////////////////////////////////
+    #endif /*USE_ASIO_ASYNC_RECV*/
+    ////////////////////////////////////////////////////////////////////
+
+    size_t get_num_recv_frames(void) const {return _num_recv_frames;}
+    size_t get_recv_frame_size(void) const {return _recv_frame_size;}
+
+    //! handle a send callback -> push the emptied memory into the fifo
+    UHD_INLINE void handle_send(void *mem){
+        boost::this_thread::disable_interruption di; //disable because the wait can throw
+        _pending_send_buffs->push_with_wait(boost::asio::buffer(mem, this->get_send_frame_size()));
     }
 
-    ssize_t send(const boost::asio::const_buffer &buff){
-        return ::send(
-            _sock_fd,
-            boost::asio::buffer_cast<const char *>(buff),
-            boost::asio::buffer_size(buff), 0
+    //! pop an empty send buffer off of the fifo and bind with the commit callback
+    managed_send_buffer::sptr get_send_buff(double timeout){
+        boost::this_thread::disable_interruption di; //disable because the wait can throw
+        asio::mutable_buffer buff;
+        if (_pending_send_buffs->pop_with_timed_wait(buff, timeout)){
+            return managed_send_buffer::make_safe(
+                buff, boost::bind(
+                    &udp_zero_copy_asio_impl::commit,
+                    shared_from_this(),
+                    asio::buffer_cast<void*>(buff), _1
+                )
+            );
+        }
+        return managed_send_buffer::sptr();
+    }
+
+    ////////////////////////////////////////////////////////////////////
+    #ifdef USE_ASIO_ASYNC_SEND
+    ////////////////////////////////////////////////////////////////////
+    //! commit a send buffer -> start an async send on the buffer
+    void commit(void *mem, size_t len){
+        _socket->async_send(
+            boost::asio::buffer(mem, len),
+            boost::bind(
+                &udp_zero_copy_asio_impl::handle_send,
+                shared_from_this(), mem
+            )
         );
     }
+
+    ////////////////////////////////////////////////////////////////////
+    #else /*USE_ASIO_ASYNC_SEND*/
+    ////////////////////////////////////////////////////////////////////
+    void commit(void *mem, size_t len){
+        _socket->send(asio::buffer(mem, len));
+        handle_send(mem);
+    }
+
+    ////////////////////////////////////////////////////////////////////
+    #endif /*USE_ASIO_ASYNC_SEND*/
+    ////////////////////////////////////////////////////////////////////
+
+    size_t get_num_send_frames(void) const {return _num_send_frames;}
+    size_t get_send_frame_size(void) const {return _send_frame_size;}
+
+private:
+    //asio guts -> socket and service
+    asio::ip::udp::socket   *_socket;
+    asio::io_service        _io_service;
+    asio::io_service::work  *_work;
+    int                     _sock_fd;
+
+    //memory management -> buffers and fifos
+    boost::thread_group _thread_group;
+    boost::shared_array<char> _send_buffer, _recv_buffer;
+    typedef bounded_buffer<asio::mutable_buffer> pending_buffs_type;
+    pending_buffs_type::sptr _pending_recv_buffs, _pending_send_buffs;
+    const size_t _recv_frame_size, _num_recv_frames;
+    const size_t _send_frame_size, _num_send_frames;
 };
 
 /***********************************************************************
  * UDP zero copy make function
  **********************************************************************/
 template<typename Opt> static void resize_buff_helper(
-    udp_zero_copy_impl::sptr udp_trans,
+    udp_zero_copy_asio_impl::sptr udp_trans,
     size_t target_size,
     const std::string &name
 ){
@@ -152,6 +319,13 @@ template<typename Opt> static void resize_buff_helper(
     if (name == "recv") min_sock_buff_size = MIN_RECV_SOCK_BUFF_SIZE;
     if (name == "send") min_sock_buff_size = MIN_SEND_SOCK_BUFF_SIZE;
 
+    std::string help_message;
+    #if defined(UHD_PLATFORM_LINUX)
+        help_message = str(boost::format(
+            "Please run: sudo sysctl -w net.core.%smem_max=%d\n"
+        ) % ((name == "recv")?"r":"w") % min_sock_buff_size);
+    #endif /*defined(UHD_PLATFORM_LINUX)*/
+
     //resize the buffer if size was provided
     if (target_size > 0){
         size_t actual_size = udp_trans->resize_buff<Opt>(target_size);
@@ -162,11 +336,11 @@ template<typename Opt> static void resize_buff_helper(
         else std::cout << boost::format(
             "Current %s sock buff size: %d bytes"
         ) % name % actual_size << std::endl;
-        if (actual_size < target_size) uhd::print_warning(str(boost::format(
+        if (actual_size < target_size) uhd::warning::post(str(boost::format(
             "The %s buffer is smaller than the requested size.\n"
             "The minimum recommended buffer size is %d bytes.\n"
-            "See the USRP2 application notes on buffer resizing.\n"
-        ) % name % min_sock_buff_size));
+            "See the transport application notes on buffer resizing.\n%s"
+        ) % name % min_sock_buff_size % help_message));
     }
 
     //only enable on platforms that are happy with the large buffer resize
@@ -181,14 +355,21 @@ template<typename Opt> static void resize_buff_helper(
 udp_zero_copy::sptr udp_zero_copy::make(
     const std::string &addr,
     const std::string &port,
-    size_t recv_buff_size,
-    size_t send_buff_size
+    const device_addr_t &hints
 ){
-    udp_zero_copy_impl::sptr udp_trans(new udp_zero_copy_impl(addr, port));
+    udp_zero_copy_asio_impl::sptr udp_trans(
+        new udp_zero_copy_asio_impl(addr, port, hints)
+    );
+
+    //extract buffer size hints from the device addr
+    size_t recv_buff_size = size_t(hints.cast<double>("recv_buff_size", 0.0));
+    size_t send_buff_size = size_t(hints.cast<double>("send_buff_size", 0.0));
 
     //call the helper to resize send and recv buffers
-    resize_buff_helper<boost::asio::socket_base::receive_buffer_size>(udp_trans, recv_buff_size, "recv");
-    resize_buff_helper<boost::asio::socket_base::send_buffer_size>   (udp_trans, send_buff_size, "send");
+    resize_buff_helper<asio::socket_base::receive_buffer_size>(udp_trans, recv_buff_size, "recv");
+    resize_buff_helper<asio::socket_base::send_buffer_size>   (udp_trans, send_buff_size, "send");
+
+    udp_trans->init(); //buffers resized -> call init() to use
 
     return udp_trans;
 }
diff --git a/host/lib/transport/usb_dummy_impl.cpp b/host/lib/transport/usb_dummy_impl.cpp
new file mode 100644
index 000000000..8a9772e7f
--- /dev/null
+++ b/host/lib/transport/usb_dummy_impl.cpp
@@ -0,0 +1,39 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/transport/usb_device_handle.hpp>
+#include <uhd/transport/usb_control.hpp>
+#include <uhd/transport/usb_zero_copy.hpp>
+#include <uhd/utils/exception.hpp>
+
+using namespace uhd;
+using namespace uhd::transport;
+
+std::vector<usb_device_handle::sptr> usb_device_handle::get_device_list(boost::uint16_t, boost::uint16_t){
+    return std::vector<usb_device_handle::sptr>(); //empty list
+}
+
+usb_control::sptr usb_control::make(usb_device_handle::sptr){
+    throw std::runtime_error("no usb support -> usb_control::make not implemented");
+}
+
+usb_zero_copy::sptr usb_zero_copy::make(
+    usb_device_handle::sptr,
+    size_t, size_t, const device_addr_t &
+){
+    throw std::runtime_error("no usb support -> usb_zero_copy::make not implemented");
+}
diff --git a/host/lib/transport/vrt_packet_handler.hpp b/host/lib/transport/vrt_packet_handler.hpp
index b603f1371..939517411 100644
--- a/host/lib/transport/vrt_packet_handler.hpp
+++ b/host/lib/transport/vrt_packet_handler.hpp
@@ -303,18 +303,18 @@ template <typename T> UHD_INLINE T get_context_code(
      * Pack a vrt header, copy-convert the data, and send it.
      *  - helper function for vrt_packet_handler::send
      ******************************************************************/
-    static UHD_INLINE void _send1(
+    static UHD_INLINE size_t _send1(
         send_state &state,
         const std::vector<const void *> &buffs,
-        size_t offset_bytes,
-        size_t num_samps,
+        const size_t offset_bytes,
+        const size_t num_samps,
         uhd::transport::vrt::if_packet_info_t &if_packet_info,
         const uhd::io_type_t &io_type,
         const uhd::otw_type_t &otw_type,
         const vrt_packer_t &vrt_packer,
         const get_send_buffs_t &get_send_buffs,
-        size_t vrt_header_offset_words32,
-        size_t chans_per_otw_buff
+        const size_t vrt_header_offset_words32,
+        const size_t chans_per_otw_buff
     ){
         //load the rest of the if_packet_info in here
         if_packet_info.num_payload_words32 = (num_samps*chans_per_otw_buff*otw_type.get_sample_size())/sizeof(boost::uint32_t);
@@ -322,7 +322,7 @@ template <typename T> UHD_INLINE T get_context_code(
 
         //get send buffers for each channel
         managed_send_buffs_t send_buffs(buffs.size()/chans_per_otw_buff);
-        UHD_ASSERT_THROW(get_send_buffs(send_buffs));
+        if (not get_send_buffs(send_buffs)) return 0;
 
         std::vector<const void *> io_buffs(chans_per_otw_buff);
         for (size_t i = 0; i < buffs.size(); i+=chans_per_otw_buff){
@@ -343,10 +343,9 @@ template <typename T> UHD_INLINE T get_context_code(
 
             //commit the samples to the zero-copy interface
             size_t num_bytes_total = (vrt_header_offset_words32+if_packet_info.num_packet_words32)*sizeof(boost::uint32_t);
-            if (send_buffs[i]->commit(num_bytes_total) < ssize_t(num_bytes_total)){
-                std::cerr << "commit to send buffer returned less than commit size" << std::endl;
-            }
+            send_buffs[i]->commit(num_bytes_total);
         }
+        return num_samps;
     }
 
     /*******************************************************************
@@ -381,7 +380,6 @@ template <typename T> UHD_INLINE T get_context_code(
         ////////////////////////////////////////////////////////////////
         case uhd::device::SEND_MODE_ONE_PACKET:{
         ////////////////////////////////////////////////////////////////
-            size_t num_samps = std::min(total_num_samps, max_samples_per_packet);
 
             //fill in parts of the packet info overwrote in full buff mode
             if_packet_info.has_tsi = metadata.has_time_spec;
@@ -389,10 +387,10 @@ template <typename T> UHD_INLINE T get_context_code(
             if_packet_info.sob = metadata.start_of_burst;
             if_packet_info.eob = metadata.end_of_burst;
 
-            _send1(
+            return _send1(
                 state,
                 buffs, 0,
-                num_samps,
+                std::min(total_num_samps, max_samples_per_packet),
                 if_packet_info,
                 io_type, otw_type,
                 vrt_packer,
@@ -400,31 +398,32 @@ template <typename T> UHD_INLINE T get_context_code(
                 vrt_header_offset_words32,
                 chans_per_otw_buff
             );
-            return num_samps;
         }
 
         ////////////////////////////////////////////////////////////////
         case uhd::device::SEND_MODE_FULL_BUFF:{
         ////////////////////////////////////////////////////////////////
-            //calculate constants for fragmentation
-            const size_t num_fragments = (total_num_samps+max_samples_per_packet-1)/max_samples_per_packet;
-            static const size_t first_fragment_index = 0;
-            const size_t final_fragment_index = num_fragments-1;
+            size_t total_num_samps_sent = 0;
 
             //loop through the following fragment indexes
-            for (size_t n = first_fragment_index; n <= final_fragment_index; n++){
+            while(total_num_samps_sent < total_num_samps){
+
+                //calculate per-loop-iteration variables
+                const size_t total_num_samps_unsent = total_num_samps - total_num_samps_sent;
+                const bool first_fragment = (total_num_samps_sent == 0);
+                const bool final_fragment = (total_num_samps_unsent <= max_samples_per_packet);
 
                 //calculate new flags for the fragments
-                if_packet_info.has_tsi = metadata.has_time_spec  and (n == first_fragment_index);
-                if_packet_info.has_tsf = metadata.has_time_spec  and (n == first_fragment_index);
-                if_packet_info.sob     = metadata.start_of_burst and (n == first_fragment_index);
-                if_packet_info.eob     = metadata.end_of_burst   and (n == final_fragment_index);
+                if_packet_info.has_tsi = metadata.has_time_spec  and first_fragment;
+                if_packet_info.has_tsf = if_packet_info.has_tsi;
+                if_packet_info.sob     = metadata.start_of_burst and first_fragment;
+                if_packet_info.eob     = metadata.end_of_burst   and final_fragment;
 
                 //send the fragment with the helper function
-                _send1(
+                const size_t num_samps_sent = _send1(
                     state,
-                    buffs, n*max_samples_per_packet*io_type.size,
-                    (n == final_fragment_index)?(total_num_samps%max_samples_per_packet):max_samples_per_packet,
+                    buffs, total_num_samps_sent*io_type.size,
+                    std::min(total_num_samps_unsent, max_samples_per_packet),
                     if_packet_info,
                     io_type, otw_type,
                     vrt_packer,
@@ -432,8 +431,10 @@ template <typename T> UHD_INLINE T get_context_code(
                     vrt_header_offset_words32,
                     chans_per_otw_buff
                 );
+                total_num_samps_sent += num_samps_sent;
+                if (num_samps_sent == 0) return total_num_samps_sent;
             }
-            return total_num_samps;
+            return total_num_samps_sent;
         }
 
         default: throw std::runtime_error("unknown send mode");
diff --git a/host/lib/transport/zero_copy.cpp b/host/lib/transport/zero_copy.cpp
index 8a1cde694..a5a864a04 100644
--- a/host/lib/transport/zero_copy.cpp
+++ b/host/lib/transport/zero_copy.cpp
@@ -16,32 +16,35 @@
 //
 
 #include <uhd/transport/zero_copy.hpp>
-#include <boost/cstdint.hpp>
-#include <boost/function.hpp>
-#include <boost/bind.hpp>
 
 using namespace uhd::transport;
 
 /***********************************************************************
- * The pure-virtual deconstructor needs an implementation to be happy
+ * Safe managed receive buffer
  **********************************************************************/
-managed_recv_buffer::~managed_recv_buffer(void){
+static void release_nop(void){
     /* NOP */
 }
 
-/***********************************************************************
- * Phony zero-copy recv interface implementation
- **********************************************************************/
-
-//! phony zero-copy recv buffer implementation
-class managed_recv_buffer_impl : public managed_recv_buffer{
+class safe_managed_receive_buffer : public managed_recv_buffer{
 public:
-    managed_recv_buffer_impl(const boost::asio::const_buffer &buff) : _buff(buff){
+    safe_managed_receive_buffer(
+        const boost::asio::const_buffer &buff,
+        const release_fcn_t &release_fcn
+    ):
+        _buff(buff), _release_fcn(release_fcn)
+    {
         /* NOP */
     }
 
-    ~managed_recv_buffer_impl(void){
-        delete [] this->cast<const boost::uint8_t *>();
+    ~safe_managed_receive_buffer(void){
+        _release_fcn();
+    }
+
+    void release(void){
+        release_fcn_t release_fcn = _release_fcn;
+        _release_fcn = &release_nop;
+        return release_fcn();
     }
 
 private:
@@ -50,64 +53,42 @@ private:
     }
 
     const boost::asio::const_buffer _buff;
+    release_fcn_t _release_fcn;
 };
 
-//! phony zero-copy recv interface implementation
-struct phony_zero_copy_recv_if::impl{
-    impl(size_t max_buff_size) : max_buff_size(max_buff_size){
-        /* NOP */
-    }
-    size_t max_buff_size;
-};
-
-phony_zero_copy_recv_if::phony_zero_copy_recv_if(size_t max_buff_size){
-    _impl = UHD_PIMPL_MAKE(impl, (max_buff_size));
-}
-
-phony_zero_copy_recv_if::~phony_zero_copy_recv_if(void){
-    /* NOP */
-}
-
-managed_recv_buffer::sptr phony_zero_copy_recv_if::get_recv_buff(void){
-    //allocate memory
-    boost::uint8_t *recv_mem = new boost::uint8_t[_impl->max_buff_size];
-
-    //call recv() with timeout option
-    ssize_t num_bytes = this->recv(boost::asio::buffer(recv_mem, _impl->max_buff_size));
-
-    if (num_bytes <= 0) return managed_recv_buffer::sptr(); //NULL sptr
-
-    //create a new managed buffer to house the data
-    return managed_recv_buffer::sptr(
-        new managed_recv_buffer_impl(boost::asio::buffer(recv_mem, num_bytes))
-    );
+managed_recv_buffer::sptr managed_recv_buffer::make_safe(
+    const boost::asio::const_buffer &buff,
+    const release_fcn_t &release_fcn
+){
+    return sptr(new safe_managed_receive_buffer(buff, release_fcn));
 }
 
 /***********************************************************************
- * Phony zero-copy send interface implementation
+ * Safe managed send buffer
  **********************************************************************/
+static void commit_nop(size_t){
+    /* NOP */
+}
 
-//! phony zero-copy send buffer implementation
-class managed_send_buffer_impl : public managed_send_buffer{
+class safe_managed_send_buffer : public managed_send_buffer{
 public:
-    typedef boost::function<ssize_t(const boost::asio::const_buffer &)> send_fcn_t;
-
-    managed_send_buffer_impl(
+    safe_managed_send_buffer(
         const boost::asio::mutable_buffer &buff,
-        const send_fcn_t &send_fcn
+        const commit_fcn_t &commit_fcn
     ):
-        _buff(buff),
-        _send_fcn(send_fcn)
+        _buff(buff), _commit_fcn(commit_fcn)
     {
         /* NOP */
     }
 
-    ~managed_send_buffer_impl(void){
-        /* NOP */
+    ~safe_managed_send_buffer(void){
+        _commit_fcn(0);
     }
 
-    ssize_t commit(size_t num_bytes){
-        return _send_fcn(boost::asio::buffer(_buff, num_bytes));
+    void commit(size_t num_bytes){
+        commit_fcn_t commit_fcn = _commit_fcn;
+        _commit_fcn = &commit_nop;
+        return commit_fcn(num_bytes);
     }
 
 private:
@@ -116,28 +97,12 @@ private:
     }
 
     const boost::asio::mutable_buffer _buff;
-    const send_fcn_t                  _send_fcn;
-};
-
-//! phony zero-copy send interface implementation
-struct phony_zero_copy_send_if::impl{
-    boost::uint8_t *send_mem;
-    managed_send_buffer::sptr send_buff;
+    commit_fcn_t _commit_fcn;
 };
 
-phony_zero_copy_send_if::phony_zero_copy_send_if(size_t max_buff_size){
-    _impl = UHD_PIMPL_MAKE(impl, ());
-    _impl->send_mem = new boost::uint8_t[max_buff_size];
-    _impl->send_buff = managed_send_buffer::sptr(new managed_send_buffer_impl(
-        boost::asio::buffer(_impl->send_mem, max_buff_size),
-        boost::bind(&phony_zero_copy_send_if::send, this, _1)
-    ));
-}
-
-phony_zero_copy_send_if::~phony_zero_copy_send_if(void){
-    delete [] _impl->send_mem;
-}
-
-managed_send_buffer::sptr phony_zero_copy_send_if::get_send_buff(void){
-    return _impl->send_buff; //FIXME there is only ever one send buff, we assume that the caller doesnt hang onto these
+safe_managed_send_buffer::sptr managed_send_buffer::make_safe(
+    const boost::asio::mutable_buffer &buff,
+    const commit_fcn_t &commit_fcn
+){
+    return sptr(new safe_managed_send_buffer(buff, commit_fcn));
 }
diff --git a/host/lib/types.cpp b/host/lib/types.cpp
index f957cd83f..4188568aa 100644
--- a/host/lib/types.cpp
+++ b/host/lib/types.cpp
@@ -17,6 +17,7 @@
 
 #include <uhd/utils/assert.hpp>
 #include <uhd/types/ranges.hpp>
+#include <uhd/types/tune_request.hpp>
 #include <uhd/types/tune_result.hpp>
 #include <uhd/types/clock_config.hpp>
 #include <uhd/types/stream_cmd.hpp>
@@ -58,6 +59,26 @@ freq_range_t::freq_range_t(double min, double max):
 }
 
 /***********************************************************************
+ * tune request
+ **********************************************************************/
+tune_request_t::tune_request_t(double target_freq):
+    target_freq(target_freq),
+    inter_freq_policy(POLICY_AUTO),
+    dsp_freq_policy(POLICY_AUTO)
+{
+    /* NOP */
+}
+
+tune_request_t::tune_request_t(double target_freq, double lo_off):
+    target_freq(target_freq),
+    inter_freq_policy(POLICY_MANUAL),
+    inter_freq(target_freq + lo_off),
+    dsp_freq_policy(POLICY_AUTO)
+{
+    /* NOP */
+}
+
+/***********************************************************************
  * tune result
  **********************************************************************/
 std::string tune_result_t::to_pp_string(void) const{
@@ -124,14 +145,14 @@ time_spec_t::time_spec_t(time_t full_secs, double frac_secs):
     /* NOP */
 }
 
-time_spec_t::time_spec_t(time_t full_secs, size_t tick_count, double tick_rate):
+time_spec_t::time_spec_t(time_t full_secs, long tick_count, double tick_rate):
     _full_secs(full_secs),
     _frac_secs(double(tick_count)/tick_rate)
 {
     /* NOP */
 }
 
-size_t time_spec_t::get_tick_count(double tick_rate) const{
+long time_spec_t::get_tick_count(double tick_rate) const{
     return boost::math::iround(this->get_frac_secs()*tick_rate);
 }
 
@@ -140,7 +161,9 @@ double time_spec_t::get_real_secs(void) const{
 }
 
 time_t time_spec_t::get_full_secs(void) const{
-    return this->_full_secs + time_t(std::floor(this->_frac_secs));
+    double intpart;
+    std::modf(this->_frac_secs, &intpart);
+    return this->_full_secs + time_t(intpart);
 }
 
 double time_spec_t::get_frac_secs(void) const{
@@ -160,13 +183,18 @@ time_spec_t &time_spec_t::operator-=(const time_spec_t &rhs){
 }
 
 bool uhd::operator==(const time_spec_t &lhs, const time_spec_t &rhs){
-    return lhs.get_full_secs() == rhs.get_full_secs() and lhs.get_frac_secs() == rhs.get_frac_secs();
+    return
+        lhs.get_full_secs() == rhs.get_full_secs() and
+        lhs.get_frac_secs() == rhs.get_frac_secs()
+    ;
 }
 
 bool uhd::operator<(const time_spec_t &lhs, const time_spec_t &rhs){
-    if (lhs.get_full_secs() < rhs.get_full_secs()) return true;
-    if (lhs.get_full_secs() > rhs.get_full_secs()) return false;
-    return lhs.get_frac_secs() < rhs.get_frac_secs();
+    return (
+        (lhs.get_full_secs() < rhs.get_full_secs()) or (
+        (lhs.get_full_secs() == rhs.get_full_secs()) and
+        (lhs.get_frac_secs() < rhs.get_frac_secs())
+    ));
 }
 
 /***********************************************************************
diff --git a/host/lib/usrp/CMakeLists.txt b/host/lib/usrp/CMakeLists.txt
index 73197bca4..c264252e1 100644
--- a/host/lib/usrp/CMakeLists.txt
+++ b/host/lib/usrp/CMakeLists.txt
@@ -23,12 +23,12 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_SOURCE_DIR}/lib/usrp/dboard_id.cpp
     ${CMAKE_SOURCE_DIR}/lib/usrp/dboard_manager.cpp
     ${CMAKE_SOURCE_DIR}/lib/usrp/dsp_utils.cpp
-    ${CMAKE_SOURCE_DIR}/lib/usrp/mimo_usrp.cpp
     ${CMAKE_SOURCE_DIR}/lib/usrp/misc_utils.cpp
-    ${CMAKE_SOURCE_DIR}/lib/usrp/simple_usrp.cpp
+    ${CMAKE_SOURCE_DIR}/lib/usrp/multi_usrp.cpp
     ${CMAKE_SOURCE_DIR}/lib/usrp/single_usrp.cpp
     ${CMAKE_SOURCE_DIR}/lib/usrp/subdev_spec.cpp
     ${CMAKE_SOURCE_DIR}/lib/usrp/tune_helper.cpp
+    ${CMAKE_SOURCE_DIR}/lib/usrp/wrapper_utils.hpp
 )
 
 INCLUDE(${CMAKE_SOURCE_DIR}/lib/usrp/dboard/CMakeLists.txt)
diff --git a/host/lib/usrp/dboard/CMakeLists.txt b/host/lib/usrp/dboard/CMakeLists.txt
index 3e995009e..8d3d11530 100644
--- a/host/lib/usrp/dboard/CMakeLists.txt
+++ b/host/lib/usrp/dboard/CMakeLists.txt
@@ -24,5 +24,6 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_SOURCE_DIR}/lib/usrp/dboard/db_wbx.cpp
     ${CMAKE_SOURCE_DIR}/lib/usrp/dboard/db_dbsrx.cpp
     ${CMAKE_SOURCE_DIR}/lib/usrp/dboard/db_unknown.cpp
+    ${CMAKE_SOURCE_DIR}/lib/usrp/dboard/db_tvrx.cpp
 )
 
diff --git a/host/lib/usrp/dboard/db_basic_and_lf.cpp b/host/lib/usrp/dboard/db_basic_and_lf.cpp
index 4b0d8bf27..4c49b3bff 100644
--- a/host/lib/usrp/dboard/db_basic_and_lf.cpp
+++ b/host/lib/usrp/dboard/db_basic_and_lf.cpp
@@ -20,6 +20,7 @@
 #include <uhd/types/ranges.hpp>
 #include <uhd/utils/assert.hpp>
 #include <uhd/utils/static.hpp>
+#include <uhd/utils/warning.hpp>
 #include <uhd/usrp/dboard_base.hpp>
 #include <uhd/usrp/dboard_manager.hpp>
 #include <boost/assign/list_of.hpp>
@@ -68,11 +69,11 @@ static const uhd::dict<std::string, subdev_conn_t> sd_name_to_conn = map_list_of
  * Register the basic and LF dboards
  **********************************************************************/
 static dboard_base::sptr make_basic_rx(dboard_base::ctor_args_t args){
-    return dboard_base::sptr(new basic_rx(args, 90e9));
+    return dboard_base::sptr(new basic_rx(args, 250e6));
 }
 
 static dboard_base::sptr make_basic_tx(dboard_base::ctor_args_t args){
-    return dboard_base::sptr(new basic_tx(args, 90e9));
+    return dboard_base::sptr(new basic_tx(args, 250e6));
 }
 
 static dboard_base::sptr make_lf_rx(dboard_base::ctor_args_t args){
@@ -149,6 +150,10 @@ void basic_rx::rx_get(const wax::obj &key_, wax::obj &val){
         val = sd_name_to_conn[get_subdev_name()];
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -157,6 +162,10 @@ void basic_rx::rx_get(const wax::obj &key_, wax::obj &val){
         val = true; //there is no LO, so it must be true!
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 2*_max_freq; //we want complex double-sided
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -178,6 +187,17 @@ void basic_rx::rx_set(const wax::obj &key_, const wax::obj &val){
     case SUBDEV_PROP_FREQ:
         return; // it wont do you much good, but you can set it
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
+    case SUBDEV_PROP_BANDWIDTH:
+        uhd::warning::post(
+            str(boost::format("%s: No tunable bandwidth, fixed filtered to %0.2fMHz")
+                % get_rx_id().to_pp_string() % _max_freq
+            )
+        );
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
@@ -241,6 +261,10 @@ void basic_tx::tx_get(const wax::obj &key_, wax::obj &val){
         val = sd_name_to_conn[get_subdev_name()];
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -249,6 +273,10 @@ void basic_tx::tx_get(const wax::obj &key_, wax::obj &val){
         val = true; //there is no LO, so it must be true!
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 2*_max_freq; //we want complex double-sided
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -270,6 +298,17 @@ void basic_tx::tx_set(const wax::obj &key_, const wax::obj &val){
     case SUBDEV_PROP_FREQ:
         return; // it wont do you much good, but you can set it
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
+    case SUBDEV_PROP_BANDWIDTH:
+        uhd::warning::post(
+            str(boost::format("%s: No tunable bandwidth, fixed filtered to %0.2fMHz")
+                % get_tx_id().to_pp_string() % _max_freq
+            )
+        );
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
diff --git a/host/lib/usrp/dboard/db_dbsrx.cpp b/host/lib/usrp/dboard/db_dbsrx.cpp
index 81434f054..85251bdf9 100644
--- a/host/lib/usrp/dboard/db_dbsrx.cpp
+++ b/host/lib/usrp/dboard/db_dbsrx.cpp
@@ -69,7 +69,7 @@ public:
 
 private:
     double _lo_freq;
-    float _bandwidth;
+    double _bandwidth;
     uhd::dict<std::string, float> _gains;
     max2118_write_regs_t _max2118_write_regs;
     max2118_read_regs_t _max2118_read_regs;
@@ -79,7 +79,7 @@ private:
 
     void set_lo_freq(double target_freq);
     void set_gain(float gain, const std::string &name);
-    void set_bandwidth(float bandwidth);
+    void set_bandwidth(double bandwidth);
 
     void send_reg(boost::uint8_t start_reg, boost::uint8_t stop_reg){
         start_reg = boost::uint8_t(std::clip(int(start_reg), 0x0, 0x5));
@@ -162,15 +162,10 @@ static dboard_base::sptr make_dbsrx(dboard_base::ctor_args_t args){
     return dboard_base::sptr(new dbsrx(args));
 }
 
-//dbid for USRP2 version
 UHD_STATIC_BLOCK(reg_dbsrx_dboard){
-    //register the factory function for the rx dbid
+    //register the factory function for the rx dbid (others version)
     dboard_manager::register_dboard(0x000D, &make_dbsrx, "DBSRX");
-}
-
-//dbid for USRP1 version
-UHD_STATIC_BLOCK(reg_dbsrx_on_usrp1_dboard){
-    //register the factory function for the rx dbid
+    //register the factory function for the rx dbid (USRP1 version)
     dboard_manager::register_dboard(0x0002, &make_dbsrx, "DBSRX");
 }
 
@@ -180,7 +175,7 @@ UHD_STATIC_BLOCK(reg_dbsrx_on_usrp1_dboard){
 dbsrx::dbsrx(ctor_args_t args) : rx_dboard_base(args){
     //warn user about incorrect DBID on USRP1, requires R193 populated
     if (this->get_iface()->get_special_props().soft_clock_divider and this->get_rx_id() == 0x000D)
-        uhd::print_warning(
+        uhd::warning::post(
             str(boost::format(
                 "DBSRX: incorrect dbid\n"
                 "Expected dbid 0x0002 and R193\n"
@@ -191,7 +186,7 @@ dbsrx::dbsrx(ctor_args_t args) : rx_dboard_base(args){
 
     //warn user about incorrect DBID on non-USRP1, requires R194 populated
     if (not this->get_iface()->get_special_props().soft_clock_divider and this->get_rx_id() == 0x0002)
-        uhd::print_warning(
+        uhd::warning::post(
             str(boost::format(
                 "DBSRX: incorrect dbid\n"
                 "Expected dbid 0x000D and R194\n"
@@ -239,11 +234,12 @@ void dbsrx::set_lo_freq(double target_freq){
     double actual_freq=0.0, pfd_freq=0.0, ref_clock=0.0;
     int R=0, N=0, r=0, m=0;
     bool update_filter_settings = false;
-
     //choose refclock
     std::vector<double> clock_rates = this->get_iface()->get_clock_rates(dboard_iface::UNIT_RX);
+    const double max_clock_rate = std::sorted(clock_rates).back();
     BOOST_FOREACH(ref_clock, std::reversed(std::sorted(clock_rates))){
         if (ref_clock > 27.0e6) continue;
+        if (size_t(max_clock_rate/ref_clock)%2 == 1) continue; //reject asymmetric clocks (odd divisors)
 
         //choose m_divider such that filter tuning constraint is met
         m = 31;
@@ -251,7 +247,7 @@ void dbsrx::set_lo_freq(double target_freq){
 
         if(dbsrx_debug) std::cerr << boost::format(
             "DBSRX: trying ref_clock %f and m_divider %d"
-        ) % (this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX)) % m << std::endl;
+        ) % (ref_clock) % m << std::endl;
 
         if (m >= 32) continue;
 
@@ -277,15 +273,17 @@ void dbsrx::set_lo_freq(double target_freq){
         }
     } 
 
-    //Assert because we failed to find a suitable combination of ref_clock, R and N 
-    UHD_ASSERT_THROW(ref_clock/(1 << m) < 1e6 or ref_clock/(1 << m) > 2.5e6);
-    UHD_ASSERT_THROW((pfd_freq < dbsrx_pfd_freq_range.min) or (pfd_freq > dbsrx_pfd_freq_range.max));
-    UHD_ASSERT_THROW((N < 256) or (N > 32768));
     done_loop:
 
+    //Assert because we failed to find a suitable combination of ref_clock, R and N 
+    UHD_ASSERT_THROW(ref_clock <= 27.0e6 and ref_clock >= 0.0);
+    UHD_ASSERT_THROW(ref_clock/m >= 1e6 and ref_clock/m <= 2.5e6);
+    UHD_ASSERT_THROW((pfd_freq >= dbsrx_pfd_freq_range.min) and (pfd_freq <= dbsrx_pfd_freq_range.max));
+    UHD_ASSERT_THROW((N >= 256) and (N <= 32768));
+
     if(dbsrx_debug) std::cerr << boost::format(
-        "DBSRX: choose ref_clock %f and m_divider %d"
-    ) % (this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX)) % m << std::endl;
+        "DBSRX: choose ref_clock (current: %f, new: %f) and m_divider %d"
+    ) % (this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX)) % ref_clock % m << std::endl;
 
     //if ref_clock or m divider changed, we need to update the filter settings
     if (ref_clock != this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX) or m != _max2118_write_regs.m_divider) update_filter_settings = true;
@@ -344,12 +342,12 @@ void dbsrx::set_lo_freq(double target_freq){
         //vtune is too low, try lower frequency vco
         if (_max2118_read_regs.adc == 0){
             if (_max2118_write_regs.osc_band == 0){
-                uhd::print_warning(
+                uhd::warning::post(
                     str(boost::format(
                         "DBSRX: Tuning exceeded vco range, _max2118_write_regs.osc_band == %d\n" 
                         ) % int(_max2118_write_regs.osc_band))
                 );
-                UHD_ASSERT_THROW(_max2118_read_regs.adc == 0);
+                UHD_ASSERT_THROW(_max2118_read_regs.adc != 0); //just to cause a throw
             }
             if (_max2118_write_regs.osc_band <= 0) break;
             _max2118_write_regs.osc_band -= 1;
@@ -358,12 +356,12 @@ void dbsrx::set_lo_freq(double target_freq){
         //vtune is too high, try higher frequency vco
         if (_max2118_read_regs.adc == 7){
             if (_max2118_write_regs.osc_band == 7){
-                uhd::print_warning(
+                uhd::warning::post(
                     str(boost::format(
                         "DBSRX: Tuning exceeded vco range, _max2118_write_regs.osc_band == %d\n" 
                         ) % int(_max2118_write_regs.osc_band))
                 );
-                UHD_ASSERT_THROW(_max2118_read_regs.adc == 0);
+                UHD_ASSERT_THROW(_max2118_read_regs.adc != 7); //just to cause a throw
             }
             if (_max2118_write_regs.osc_band >= 7) break;
             _max2118_write_regs.osc_band += 1;
@@ -401,6 +399,7 @@ void dbsrx::set_lo_freq(double target_freq){
         << boost::format("    Ref    Freq=%fMHz\n") % (ref_clock/1e6)
         << boost::format("    Target Freq=%fMHz\n") % (target_freq/1e6)
         << boost::format("    Actual Freq=%fMHz\n") % (_lo_freq/1e6)
+        << boost::format("    VCO    Freq=%fMHz\n") % (vco_freq/1e6)
         << std::endl;
 
     if (update_filter_settings) set_bandwidth(_bandwidth);
@@ -480,9 +479,9 @@ void dbsrx::set_gain(float gain, const std::string &name){
 /***********************************************************************
  * Bandwidth Handling
  **********************************************************************/
-void dbsrx::set_bandwidth(float bandwidth){
+void dbsrx::set_bandwidth(double bandwidth){
     //clip the input
-    bandwidth = std::clip<float>(bandwidth, 4e6, 33e6);
+    bandwidth = std::clip<double>(bandwidth, 4e6, 33e6);
 
     double ref_clock = this->get_iface()->get_clock_rate(dboard_iface::UNIT_RX);
     
@@ -492,7 +491,7 @@ void dbsrx::set_bandwidth(float bandwidth){
     _max2118_write_regs.f_dac = std::clip<int>(int((((bandwidth*_max2118_write_regs.m_divider)/ref_clock) - 4)/0.145),0,127);
 
     //determine actual bandwidth
-    _bandwidth = float((ref_clock/(_max2118_write_regs.m_divider))*(4+0.145*_max2118_write_regs.f_dac));
+    _bandwidth = double((ref_clock/(_max2118_write_regs.m_divider))*(4+0.145*_max2118_write_regs.f_dac));
 
     if (dbsrx_debug) std::cerr << boost::format(
         "DBSRX Filter Bandwidth: %f MHz, m: %d, f_dac: %d\n"
@@ -551,6 +550,10 @@ void dbsrx::rx_get(const wax::obj &key_, wax::obj &val){
         val = SUBDEV_CONN_COMPLEX_IQ;
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -559,14 +562,8 @@ void dbsrx::rx_get(const wax::obj &key_, wax::obj &val){
         val = this->get_locked();
         return;
 
-/*
-    case SUBDEV_PROP_RSSI:
-        val = this->get_rssi();
-        return;
-*/
-
     case SUBDEV_PROP_BANDWIDTH:
-        val = _bandwidth;
+        val = 2*_bandwidth; //_bandwidth is low-pass, we want complex double-sided
         return;
 
     default: UHD_THROW_PROP_GET_ERROR();
@@ -587,8 +584,11 @@ void dbsrx::rx_set(const wax::obj &key_, const wax::obj &val){
         this->set_gain(val.as<float>(), key.name);
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
     case SUBDEV_PROP_BANDWIDTH:
-        this->set_bandwidth(val.as<float>());
+        this->set_bandwidth(val.as<double>()/2.0); //complex double-sided, we want low-pass
         return;
 
     default: UHD_THROW_PROP_SET_ERROR();
diff --git a/host/lib/usrp/dboard/db_rfx.cpp b/host/lib/usrp/dboard/db_rfx.cpp
index c3ab96e59..12e458d8c 100644
--- a/host/lib/usrp/dboard/db_rfx.cpp
+++ b/host/lib/usrp/dboard/db_rfx.cpp
@@ -43,6 +43,7 @@
 #include <uhd/utils/assert.hpp>
 #include <uhd/utils/static.hpp>
 #include <uhd/utils/algorithm.hpp>
+#include <uhd/utils/warning.hpp>
 #include <uhd/usrp/dboard_id.hpp>
 #include <uhd/usrp/dboard_base.hpp>
 #include <uhd/usrp/dboard_manager.hpp>
@@ -152,12 +153,12 @@ static dboard_base::sptr make_rfx_flex2400(dboard_base::ctor_args_t args){
 }
 
 UHD_STATIC_BLOCK(reg_rfx_dboards){
-    dboard_manager::register_dboard(0x0024, 0x0028, &make_rfx_flex400,  "Flex 400 MIMO B");
-    dboard_manager::register_dboard(0x0025, 0x0029, &make_rfx_flex900,  "Flex 900 MIMO B");
-    dboard_manager::register_dboard(0x0034, 0x0035, &make_rfx_flex1800, "Flex 1800 MIMO B");
-    dboard_manager::register_dboard(0x0026, 0x002a, &make_rfx_flex1200, "Flex 1200 MIMO B");
-    dboard_manager::register_dboard(0x002c, 0x002d, &make_rfx_flex2200, "Flex 2200 MIMO B");
-    dboard_manager::register_dboard(0x0027, 0x002b, &make_rfx_flex2400, "Flex 2400 MIMO B");
+    dboard_manager::register_dboard(0x0024, 0x0028, &make_rfx_flex400,  "RFX400");
+    dboard_manager::register_dboard(0x0025, 0x0029, &make_rfx_flex900,  "RFX900");
+    dboard_manager::register_dboard(0x0034, 0x0035, &make_rfx_flex1800, "RFX1800");
+    dboard_manager::register_dboard(0x0026, 0x002a, &make_rfx_flex1200, "RFX1200");
+    dboard_manager::register_dboard(0x002c, 0x002d, &make_rfx_flex2200, "RFX2200");
+    dboard_manager::register_dboard(0x0027, 0x002b, &make_rfx_flex2400, "RFX2400");
 }
 
 /***********************************************************************
@@ -444,6 +445,10 @@ void rfx_xcvr::rx_get(const wax::obj &key_, wax::obj &val){
         val = SUBDEV_CONN_COMPLEX_QI;
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -452,6 +457,10 @@ void rfx_xcvr::rx_get(const wax::obj &key_, wax::obj &val){
         val = this->get_locked(dboard_iface::UNIT_RX);
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 2*20.0e6; //30MHz low-pass, we want complex double-sided
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -474,6 +483,15 @@ void rfx_xcvr::rx_set(const wax::obj &key_, const wax::obj &val){
         this->set_rx_ant(val.as<std::string>());
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
+    case SUBDEV_PROP_BANDWIDTH:
+        uhd::warning::post(
+            str(boost::format("RFX: No tunable bandwidth, fixed filtered to 40MHz"))
+        );
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
@@ -524,6 +542,10 @@ void rfx_xcvr::tx_get(const wax::obj &key_, wax::obj &val){
         val = SUBDEV_CONN_COMPLEX_IQ;
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = true;
         return;
@@ -532,6 +554,10 @@ void rfx_xcvr::tx_get(const wax::obj &key_, wax::obj &val){
         val = this->get_locked(dboard_iface::UNIT_TX);
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 2*20.0e6; //30MHz low-pass, we want complex double-sided
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -554,6 +580,15 @@ void rfx_xcvr::tx_set(const wax::obj &key_, const wax::obj &val){
         this->set_tx_ant(val.as<std::string>());
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
+    case SUBDEV_PROP_BANDWIDTH:
+        uhd::warning::post(
+            str(boost::format("RFX: No tunable bandwidth, fixed filtered to 40MHz"))
+        );
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
diff --git a/host/lib/usrp/dboard/db_tvrx.cpp b/host/lib/usrp/dboard/db_tvrx.cpp
new file mode 100644
index 000000000..1f3c76556
--- /dev/null
+++ b/host/lib/usrp/dboard/db_tvrx.cpp
@@ -0,0 +1,495 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+// No RX IO Pins Used
+
+// RX IO Functions
+
+//ADC/DAC functions:
+//DAC 1: RF AGC
+//DAC 2: IF AGC
+
+//min freq: 50e6
+//max freq: 860e6
+//gain range: [0:1dB:115dB]
+
+#include <uhd/utils/static.hpp>
+#include <uhd/utils/assert.hpp>
+#include <uhd/utils/algorithm.hpp>
+#include <uhd/utils/warning.hpp>
+#include <uhd/types/ranges.hpp>
+#include <uhd/types/dict.hpp>
+#include <uhd/usrp/subdev_props.hpp>
+#include <uhd/usrp/dboard_base.hpp>
+#include <uhd/usrp/dboard_manager.hpp>
+#include <boost/assign/list_of.hpp>
+#include <boost/format.hpp>
+#include <boost/thread.hpp>
+#include <boost/array.hpp>
+#include <boost/math/special_functions/round.hpp>
+#include <utility>
+#include <cmath>
+#include <cfloat>
+#include <limits>
+#include <tuner_4937di5_regs.hpp>
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace boost::assign;
+
+/***********************************************************************
+ * The tvrx constants
+ **********************************************************************/
+static const bool tvrx_debug = false;
+
+static const freq_range_t tvrx_freq_range(50e6, 860e6);
+
+static const prop_names_t tvrx_antennas = list_of("RX");
+
+static const uhd::dict<std::string, freq_range_t> tvrx_freq_ranges = map_list_of
+    ("VHFLO", freq_range_t(50e6, 158e6))
+    ("VHFHI", freq_range_t(158e6, 454e6))
+    ("UHF"  , freq_range_t(454e6, 860e6))
+;
+
+static const boost::array<double, 17> vhflo_gains_db =
+    {{-6.00000, -6.00000, -6.00000, -4.00000, 0.00000,
+     5.00000, 10.00000, 17.40000, 26.30000, 36.00000,
+     43.00000, 48.00000, 49.50000, 50.10000, 50.30000,
+     50.30000, 50.30000}};
+
+static const boost::array<double, 17> vhfhi_gains_db =
+    {{-13.3000,  -13.3000,  -13.3000,   -1.0000,    7.7000,
+    11.0000,   14.7000,   19.3000,   26.1000,   36.0000,
+    42.7000,   46.0000,   47.0000,   47.8000,   48.2000,
+    48.2000,   48.2000}};
+
+static const boost::array<double, 17> uhf_gains_db =
+    {{-8.0000,   -8.0000,   -7.0000,    4.0000,   10.2000,
+     14.5000,   17.5000,   20.0000,   24.5000,   30.8000,
+     37.0000,   39.8000,   40.7000,   41.6000,   42.6000,
+     43.2000,   43.8000}};
+
+static const boost::array<double, 17> tvrx_if_gains_db =
+    {{-1.50000,   -1.50000,   -1.50000,   -1.00000,    0.20000,
+     2.10000,    4.30000,    6.40000,    9.00000,   12.00000,
+     14.80000,   18.20000,   26.10000,   32.50000,  32.50000,
+     32.50000,   32.50000}};
+
+//gain linearization data
+//this is from the datasheet and is dB vs. volts (below)
+//i tried to curve fit this, but it's really just so nonlinear that you'd
+//need dang near as many coefficients as to just map it like this and interp.
+//these numbers are culled from the 4937DI5 datasheet and are probably totally inaccurate
+//but if it's better than the old linear fit i'm happy
+static const uhd::dict<std::string, boost::array<double, 17> > tvrx_rf_gains_db = map_list_of
+    ("VHFLO", vhflo_gains_db)
+    ("VHFHI", vhfhi_gains_db)
+    ("UHF"  , uhf_gains_db)
+;
+
+//sample voltages for the above points
+static const boost::array<double, 17> tvrx_gains_volts =
+    {{0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0}};
+
+static uhd::dict<std::string, gain_range_t> get_tvrx_gain_ranges(void) {
+    double rfmax = 0.0, rfmin = FLT_MAX;
+    BOOST_FOREACH(const std::string range, tvrx_rf_gains_db.keys()) {
+        double my_max = tvrx_rf_gains_db[range].back(); //we're assuming it's monotonic
+        double my_min = tvrx_rf_gains_db[range].front(); //if it's not this is wrong wrong wrong
+        if(my_max > rfmax) rfmax = my_max;
+        if(my_min < rfmin) rfmin = my_min;
+    }
+
+    double ifmin = tvrx_if_gains_db.front();
+    double ifmax = tvrx_if_gains_db.back();
+
+    return map_list_of
+        ("RF", gain_range_t(float(rfmin), float(rfmax), float((rfmax-rfmin)/4096.0)))
+        ("IF", gain_range_t(float(ifmin), float(ifmax), float((ifmax-ifmin)/4096.0)))
+    ;
+}
+
+static const double opamp_gain = 1.22; //onboard DAC opamp gain
+static const double tvrx_if_freq = 43.75e6; //IF freq of TVRX module
+static const boost::uint16_t reference_divider = 640; //clock reference divider to use
+static const double reference_freq = 4.0e6;
+
+/***********************************************************************
+ * The tvrx dboard class
+ **********************************************************************/
+class tvrx : public rx_dboard_base{
+public:
+    tvrx(ctor_args_t args);
+    ~tvrx(void);
+
+    void rx_get(const wax::obj &key, wax::obj &val);
+    void rx_set(const wax::obj &key, const wax::obj &val);
+
+private:
+    uhd::dict<std::string, float> _gains;
+    double _lo_freq;
+    tuner_4937di5_regs_t _tuner_4937di5_regs;
+    boost::uint8_t _tuner_4937di5_addr(void){
+        return (this->get_iface()->get_special_props().mangle_i2c_addrs)? 0x61 : 0x60; //ok really? we could rename that call
+    };
+
+    void set_gain(float gain, const std::string &name);
+    void set_freq(double freq);
+
+    void update_regs(void){
+        byte_vector_t regs_vector(4);
+
+        //get the register data
+        for(int i=0; i<4; i++){
+            regs_vector[i] = _tuner_4937di5_regs.get_reg(i);
+            if(tvrx_debug) std::cerr << boost::format(
+                "tvrx: send reg 0x%02x, value 0x%04x"
+            ) % int(i) % int(regs_vector[i]) << std::endl;
+        }
+
+        //send the data
+        this->get_iface()->write_i2c(
+            _tuner_4937di5_addr(), regs_vector
+        );
+    }
+
+};
+
+/***********************************************************************
+ * Register the tvrx dboard
+ **********************************************************************/
+static dboard_base::sptr make_tvrx(dboard_base::ctor_args_t args){
+    return dboard_base::sptr(new tvrx(args));
+}
+
+UHD_STATIC_BLOCK(reg_tvrx_dboard){
+    //register the factory function for the rx dbid
+    dboard_manager::register_dboard(0x0040, &make_tvrx, "TVRX");
+}
+
+/***********************************************************************
+ * Structors
+ **********************************************************************/
+tvrx::tvrx(ctor_args_t args) : rx_dboard_base(args){
+    this->get_iface()->set_clock_enabled(dboard_iface::UNIT_RX, true);
+
+    //set the gpio directions and atr controls (identically)
+    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, 0x0); // All unused in atr
+    if (this->get_iface()->get_special_props().soft_clock_divider){
+        this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, 0x1); // GPIO0 is clock
+    }
+    else{
+        this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, 0x0); // All Inputs
+    }
+
+    //send initial register settings if necessary
+
+    //set default freq
+    _lo_freq = tvrx_freq_range.min + tvrx_if_freq; //init _lo_freq to a sane default
+    set_freq(tvrx_freq_range.min);
+
+    //set default gains
+    BOOST_FOREACH(const std::string &name, get_tvrx_gain_ranges().keys()){
+        set_gain(get_tvrx_gain_ranges()[name].min, name);
+    }
+}
+
+tvrx::~tvrx(void){
+}
+
+/*! Return a string corresponding to the relevant band
+ * \param freq the frequency of interest
+ * \return a string corresponding to the band
+ */
+
+static std::string get_band(double freq) {
+    BOOST_FOREACH(const std::string &band, tvrx_freq_ranges.keys()) {
+        if(freq >= tvrx_freq_ranges[band].min && freq <= tvrx_freq_ranges[band].max){
+            if(tvrx_debug) std::cout << "Band: " << band << std::endl;
+            return band;
+        }
+    }
+    UHD_THROW_INVALID_CODE_PATH();
+}
+
+/***********************************************************************
+ * Gain Handling
+ **********************************************************************/
+/*!
+ * Execute a linear interpolation to find the voltage corresponding to a desired gain
+ * \param gain the desired gain in dB
+ * \param db_vector the vector of dB readings
+ * \param volts_vector the corresponding vector of voltages db_vector was sampled at
+ * \return a voltage to feed the TVRX analog gain
+ */
+
+static double gain_interp(double gain, boost::array<double, 17> db_vector, boost::array<double, 17> volts_vector) {
+    double volts;
+    gain = std::clip<double>(gain, db_vector.front(), db_vector.back()); //let's not get carried away here
+
+    boost::uint8_t gain_step = 0;
+    //find which bin we're in
+    for(size_t i = 0; i < db_vector.size()-1; i++) {
+        if(gain >= db_vector[i] && gain <= db_vector[i+1]) gain_step = i;
+    }
+
+    //find the current slope for linear interpolation
+    double slope = (volts_vector[gain_step + 1] - volts_vector[gain_step])
+                / (db_vector[gain_step + 1] - db_vector[gain_step]);
+
+    //the problem here is that for gains approaching the maximum, the voltage slope becomes infinite
+    //i.e., a small change in gain requires an infinite change in voltage
+    //to cope, we limit the slope
+
+    if(slope == std::numeric_limits<double>::infinity())
+        return volts_vector[gain_step];
+
+    //use the volts per dB slope to find the final interpolated voltage
+    volts = volts_vector[gain_step] + (slope * (gain - db_vector[gain_step]));
+
+    if(tvrx_debug)
+        std::cout << "Gain interp: gain: " << gain << ", gain_step: " << int(gain_step) << ", slope: " << slope << ", volts: " << volts << std::endl;
+
+    return volts;
+}
+
+/*!
+ * Convert a requested gain for the RF gain into a DAC voltage.
+ * The gain passed into the function will be set to the actual value.
+ * \param gain the requested gain in dB
+ * \return dac voltage value
+ */
+
+static float rf_gain_to_voltage(float gain, double lo_freq){
+    //clip the input
+    gain = std::clip<float>(gain, get_tvrx_gain_ranges()["RF"].min, get_tvrx_gain_ranges()["RF"].max);
+
+    //first we need to find out what band we're in, because gains are different across different bands
+    std::string band = get_band(lo_freq + tvrx_if_freq);
+
+    //this is the voltage at the TVRX gain input
+    double gain_volts = gain_interp(gain, tvrx_rf_gains_db[band], tvrx_gains_volts);
+    //this is the voltage at the USRP DAC output
+    double dac_volts = gain_volts / opamp_gain;
+
+    dac_volts = std::clip<double>(dac_volts, 0.0, 3.3);
+
+    if (tvrx_debug) std::cerr << boost::format(
+        "tvrx RF AGC gain: %f dB, dac_volts: %f V"
+    ) % gain % dac_volts << std::endl;
+
+    return float(dac_volts);
+}
+
+/*!
+ * Convert a requested gain for the IF gain into a DAC voltage.
+ * The gain passed into the function will be set to the actual value.
+ * \param gain the requested gain in dB
+ * \return dac voltage value
+ */
+
+static float if_gain_to_voltage(float gain){
+    //clip the input
+    gain = std::clip<float>(gain, get_tvrx_gain_ranges()["IF"].min, get_tvrx_gain_ranges()["IF"].max);
+
+    double gain_volts = gain_interp(gain, tvrx_if_gains_db, tvrx_gains_volts);
+    double dac_volts = gain_volts / opamp_gain;
+
+    dac_volts = std::clip<double>(dac_volts, 0.0, 3.3);
+
+    if (tvrx_debug) std::cerr << boost::format(
+        "tvrx IF AGC gain: %f dB, dac_volts: %f V"
+    ) % gain % dac_volts << std::endl;
+
+    return float(dac_volts);
+}
+
+void tvrx::set_gain(float gain, const std::string &name){
+    assert_has(get_tvrx_gain_ranges().keys(), name, "tvrx gain name");
+    if (name == "RF"){
+        this->get_iface()->write_aux_dac(dboard_iface::UNIT_RX, dboard_iface::AUX_DAC_B, rf_gain_to_voltage(gain, _lo_freq));
+    }
+    else if(name == "IF"){
+        this->get_iface()->write_aux_dac(dboard_iface::UNIT_RX, dboard_iface::AUX_DAC_A, if_gain_to_voltage(gain));
+    }
+    else UHD_THROW_INVALID_CODE_PATH();
+    _gains[name] = gain;
+}
+
+/*!
+ * Set the tuner to center the desired frequency at 43.75MHz
+ * \param freq the requested frequency
+ */
+
+void tvrx::set_freq(double freq) {
+    freq = std::clip<double>(freq, tvrx_freq_range.min, tvrx_freq_range.max);
+    std::string prev_band = get_band(_lo_freq - tvrx_if_freq);
+    std::string new_band = get_band(freq);
+
+    double target_lo_freq = freq + tvrx_if_freq; //the desired LO freq for high-side mixing
+    double f_ref = reference_freq / double(reference_divider); //your tuning step size
+
+    int divisor = int((target_lo_freq + (f_ref * 4.0)) / (f_ref * 8)); //the divisor we'll use
+    double actual_lo_freq = (f_ref * 8 * divisor); //the LO freq we'll actually get
+
+    if((divisor & ~0x7fff)) UHD_THROW_INVALID_CODE_PATH();
+
+    //now we update the registers
+    _tuner_4937di5_regs.db1 = (divisor >> 8) & 0xff;
+    _tuner_4937di5_regs.db2 = divisor & 0xff;
+
+    if(new_band == "VHFLO") _tuner_4937di5_regs.bandsel = tuner_4937di5_regs_t::BANDSEL_VHFLO;
+    else if(new_band == "VHFHI") _tuner_4937di5_regs.bandsel = tuner_4937di5_regs_t::BANDSEL_VHFHI;
+    else if(new_band == "UHF") _tuner_4937di5_regs.bandsel = tuner_4937di5_regs_t::BANDSEL_UHF;
+    else UHD_THROW_INVALID_CODE_PATH();
+
+    _tuner_4937di5_regs.power = tuner_4937di5_regs_t::POWER_OFF;
+    update_regs();
+
+    //ok don't forget to reset RF gain here if the new band != the old band
+    //we do this because the gains are different for different band settings
+    //not FAR off, but we do this to be consistent
+    if(prev_band != new_band) set_gain(_gains["RF"], "RF");
+
+    if(tvrx_debug)
+        std::cout << boost::format("set_freq: target LO: %f f_ref: %f divisor: %i actual LO: %f") % target_lo_freq % f_ref % divisor % actual_lo_freq << std::endl;
+
+    _lo_freq = actual_lo_freq; //for rx props
+}
+
+/***********************************************************************
+ * Get the alias frequency of frequency freq when sampled at fs.
+ * \param freq the frequency of interest
+ * \param fs the sample rate
+ * \return the alias frequency
+ **********************************************************************/
+
+static double get_alias(double freq, double fs) {
+    double alias;
+    freq = fmod(freq, fs);
+    if(freq >= (fs/2)) {
+        alias = fs - freq;
+    } else {
+        alias = freq;
+    }
+    return alias;
+}
+
+/***********************************************************************
+ * RX Get and Set
+ **********************************************************************/
+void tvrx::rx_get(const wax::obj &key_, wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+    double codec_rate;
+
+    //handle the get request conditioned on the key
+    switch(key.as<subdev_prop_t>()){
+    case SUBDEV_PROP_NAME:
+        val = get_rx_id().to_pp_string();
+        return;
+
+    case SUBDEV_PROP_OTHERS:
+        val = prop_names_t(); //empty
+        return;
+
+    case SUBDEV_PROP_GAIN:
+        assert_has(_gains.keys(), key.name, "tvrx gain name");
+        val = _gains[key.name];
+        return;
+
+    case SUBDEV_PROP_GAIN_RANGE:
+        assert_has(get_tvrx_gain_ranges().keys(), key.name, "tvrx gain name");
+        val = get_tvrx_gain_ranges()[key.name];
+        return;
+
+    case SUBDEV_PROP_GAIN_NAMES:
+        val = prop_names_t(get_tvrx_gain_ranges().keys());
+        return;
+
+    case SUBDEV_PROP_FREQ:
+    /*
+     * so here we have to do some magic. because the TVRX uses a relatively high IF,
+     * we have to watch the sample rate to see if the IF will be aliased
+     * or if it will fall within Nyquist.
+     */
+        codec_rate = this->get_iface()->get_codec_rate(dboard_iface::UNIT_RX);
+        val = (_lo_freq - tvrx_if_freq) + get_alias(tvrx_if_freq, codec_rate);
+        return;
+
+    case SUBDEV_PROP_FREQ_RANGE:
+        val = tvrx_freq_range;
+        return;
+
+    case SUBDEV_PROP_ANTENNA:
+        val = tvrx_antennas.front(); //there's only one
+        return;
+
+    case SUBDEV_PROP_ANTENNA_NAMES:
+        val = tvrx_antennas;
+        return;
+
+    case SUBDEV_PROP_CONNECTION:
+        val = SUBDEV_CONN_COMPLEX_IQ;
+        return;
+
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
+    case SUBDEV_PROP_USE_LO_OFFSET:
+        val = false;
+        return;
+
+    case SUBDEV_PROP_LO_LOCKED:
+        val = true;
+        return;
+
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 6.0e6; //30MHz low-pass, we want complex double-sided
+        return;
+
+    default: UHD_THROW_PROP_GET_ERROR();
+    }
+}
+
+void tvrx::rx_set(const wax::obj &key_, const wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<subdev_prop_t>()){
+    case SUBDEV_PROP_GAIN:
+        this->set_gain(val.as<float>(), key.name);
+        return;
+
+    case SUBDEV_PROP_FREQ:
+        this->set_freq(val.as<double>());
+        return;
+
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
+    case SUBDEV_PROP_BANDWIDTH:
+        uhd::warning::post(
+            str(boost::format("TVRX: No tunable bandwidth, fixed filtered to 6MHz"))
+        );
+        return;
+
+    default: UHD_THROW_PROP_SET_ERROR();
+    }
+}
+
diff --git a/host/lib/usrp/dboard/db_unknown.cpp b/host/lib/usrp/dboard/db_unknown.cpp
index f6f4f4a61..a342471c4 100644
--- a/host/lib/usrp/dboard/db_unknown.cpp
+++ b/host/lib/usrp/dboard/db_unknown.cpp
@@ -19,6 +19,7 @@
 #include <uhd/types/ranges.hpp>
 #include <uhd/utils/assert.hpp>
 #include <uhd/utils/static.hpp>
+#include <uhd/utils/warning.hpp>
 #include <uhd/usrp/dboard_base.hpp>
 #include <uhd/usrp/dboard_manager.hpp>
 #include <boost/assign/list_of.hpp>
@@ -122,6 +123,10 @@ void unknown_rx::rx_get(const wax::obj &key_, wax::obj &val){
         val = SUBDEV_CONN_COMPLEX_IQ;
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -130,6 +135,10 @@ void unknown_rx::rx_get(const wax::obj &key_, wax::obj &val){
         val = true; //there is no LO, so it must be true!
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 0.0;
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -151,12 +160,21 @@ void unknown_rx::rx_set(const wax::obj &key_, const wax::obj &val){
     case SUBDEV_PROP_FREQ:
         return; // it wont do you much good, but you can set it
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
+    case SUBDEV_PROP_BANDWIDTH:
+        uhd::warning::post(
+            str(boost::format("Unknown Daughterboard: No tunable bandwidth, fixed filtered to 0.0MHz"))
+        );
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
 
 /***********************************************************************
- * Basic and LF TX dboard
+ * Unknown TX dboard
  **********************************************************************/
 unknown_tx::unknown_tx(ctor_args_t args) : tx_dboard_base(args){
     /* NOP */
@@ -211,6 +229,10 @@ void unknown_tx::tx_get(const wax::obj &key_, wax::obj &val){
         val = SUBDEV_CONN_COMPLEX_IQ;
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -219,6 +241,10 @@ void unknown_tx::tx_get(const wax::obj &key_, wax::obj &val){
         val = true; //there is no LO, so it must be true!
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 0.0;
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -240,6 +266,15 @@ void unknown_tx::tx_set(const wax::obj &key_, const wax::obj &val){
     case SUBDEV_PROP_FREQ:
         return; // it wont do you much good, but you can set it
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
+    case SUBDEV_PROP_BANDWIDTH:
+        uhd::warning::post(
+            str(boost::format("Unknown Daughterboard: No tunable bandwidth, fixed filtered to 0.0MHz"))
+        );
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
diff --git a/host/lib/usrp/dboard/db_wbx.cpp b/host/lib/usrp/dboard/db_wbx.cpp
index ccd897674..647f1b975 100644
--- a/host/lib/usrp/dboard/db_wbx.cpp
+++ b/host/lib/usrp/dboard/db_wbx.cpp
@@ -71,6 +71,7 @@
 #include <uhd/utils/assert.hpp>
 #include <uhd/utils/static.hpp>
 #include <uhd/utils/algorithm.hpp>
+#include <uhd/utils/warning.hpp>
 #include <uhd/usrp/dboard_base.hpp>
 #include <uhd/usrp/dboard_manager.hpp>
 #include <boost/assign/list_of.hpp>
@@ -154,7 +155,7 @@ static dboard_base::sptr make_wbx(dboard_base::ctor_args_t args){
 }
 
 UHD_STATIC_BLOCK(reg_wbx_dboards){
-    dboard_manager::register_dboard(0x0052, 0x0053, &make_wbx, "WBX");
+    dboard_manager::register_dboard(0x0053, 0x0052, &make_wbx, "WBX");
 }
 
 /***********************************************************************
@@ -513,6 +514,10 @@ void wbx_xcvr::rx_get(const wax::obj &key_, wax::obj &val){
         val = SUBDEV_CONN_COMPLEX_IQ;
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -521,6 +526,10 @@ void wbx_xcvr::rx_get(const wax::obj &key_, wax::obj &val){
         val = this->get_locked(dboard_iface::UNIT_RX);
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 2*30.0e6; //20MHz low-pass, we want complex double-sided
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -543,6 +552,15 @@ void wbx_xcvr::rx_set(const wax::obj &key_, const wax::obj &val){
         this->set_rx_ant(val.as<std::string>());
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
+    case SUBDEV_PROP_BANDWIDTH:
+        uhd::warning::post(
+            str(boost::format("WBX: No tunable bandwidth, fixed filtered to 40MHz"))
+        );
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
@@ -597,6 +615,10 @@ void wbx_xcvr::tx_get(const wax::obj &key_, wax::obj &val){
         val = SUBDEV_CONN_COMPLEX_IQ;
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -605,6 +627,10 @@ void wbx_xcvr::tx_get(const wax::obj &key_, wax::obj &val){
         val = this->get_locked(dboard_iface::UNIT_TX);
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 2*30.0e6; //20MHz low-pass, we want complex double-sided
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -627,6 +653,15 @@ void wbx_xcvr::tx_set(const wax::obj &key_, const wax::obj &val){
         this->set_tx_ant(val.as<std::string>());
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
+    case SUBDEV_PROP_BANDWIDTH:
+        uhd::warning::post(
+            str(boost::format("WBX: No tunable bandwidth, fixed filtered to 40MHz"))
+        );
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
diff --git a/host/lib/usrp/dboard/db_xcvr2450.cpp b/host/lib/usrp/dboard/db_xcvr2450.cpp
index 798ff74a3..be0e42b92 100644
--- a/host/lib/usrp/dboard/db_xcvr2450.cpp
+++ b/host/lib/usrp/dboard/db_xcvr2450.cpp
@@ -51,6 +51,7 @@
 #include <uhd/utils/static.hpp>
 #include <uhd/utils/assert.hpp>
 #include <uhd/utils/algorithm.hpp>
+#include <uhd/utils/warning.hpp>
 #include <uhd/types/ranges.hpp>
 #include <uhd/types/dict.hpp>
 #include <uhd/usrp/subdev_props.hpp>
@@ -72,6 +73,7 @@ using namespace boost::assign;
 static const bool xcvr2450_debug = false;
 
 static const freq_range_t xcvr_freq_range(2.4e9, 6.0e9);
+static const freq_range_t xcvr_freq_band_seperation(2.5e9, 4.9e9);
 
 static const prop_names_t xcvr_antennas = list_of("J1")("J2");
 
@@ -100,6 +102,7 @@ public:
 
 private:
     double _lo_freq;
+    double _rx_bandwidth, _tx_bandwidth;
     uhd::dict<std::string, float> _tx_gains, _rx_gains;
     std::string _tx_ant, _rx_ant;
     int _ad9515div;
@@ -110,6 +113,8 @@ private:
     void set_rx_ant(const std::string &ant);
     void set_tx_gain(float gain, const std::string &name);
     void set_rx_gain(float gain, const std::string &name);
+    void set_rx_bandwidth(double bandwidth);
+    void set_tx_bandwidth(double bandwidth);
 
     void update_atr(void);
     void spi_reset(void);
@@ -176,6 +181,9 @@ xcvr2450::xcvr2450(ctor_args_t args) : xcvr_dboard_base(args){
 
     spi_reset(); //prepare the spi
 
+    _rx_bandwidth = 9.5e6;
+    _tx_bandwidth = 12.0e6;
+
     //setup the misc max2829 registers
     _max2829_regs.mimo_select         = max2829_regs_t::MIMO_SELECT_MIMO;
     _max2829_regs.band_sel_mimo       = max2829_regs_t::BAND_SEL_MIMO_MIMO;
@@ -183,7 +191,7 @@ xcvr2450::xcvr2450(ctor_args_t args) : xcvr_dboard_base(args){
     _max2829_regs.rssi_high_bw        = max2829_regs_t::RSSI_HIGH_BW_6MHZ;
     _max2829_regs.tx_lpf_coarse_adj   = max2829_regs_t::TX_LPF_COARSE_ADJ_12MHZ;
     _max2829_regs.rx_lpf_coarse_adj   = max2829_regs_t::RX_LPF_COARSE_ADJ_9_5MHZ;
-    _max2829_regs.rx_lpf_fine_adj     = max2829_regs_t::RX_LPF_FINE_ADJ_95;
+    _max2829_regs.rx_lpf_fine_adj     = max2829_regs_t::RX_LPF_FINE_ADJ_100;
     _max2829_regs.rx_vga_gain_spi     = max2829_regs_t::RX_VGA_GAIN_SPI_SPI;
     _max2829_regs.rssi_output_range   = max2829_regs_t::RSSI_OUTPUT_RANGE_HIGH;
     _max2829_regs.rssi_op_mode        = max2829_regs_t::RSSI_OP_MODE_ENABLED;
@@ -244,15 +252,24 @@ void xcvr2450::update_atr(void){
     this->get_iface()->set_atr_reg(dboard_iface::UNIT_RX, dboard_iface::ATR_REG_IDLE,        POWER_UP_RXIO | RX_DIS_RXIO);
     this->get_iface()->set_atr_reg(dboard_iface::UNIT_RX, dboard_iface::ATR_REG_RX_ONLY,     POWER_UP_RXIO | RX_ENB_RXIO);
     this->get_iface()->set_atr_reg(dboard_iface::UNIT_RX, dboard_iface::ATR_REG_TX_ONLY,     POWER_UP_RXIO | RX_DIS_RXIO);
-    this->get_iface()->set_atr_reg(dboard_iface::UNIT_RX, dboard_iface::ATR_REG_FULL_DUPLEX, POWER_UP_RXIO | RX_ENB_RXIO);
+    this->get_iface()->set_atr_reg(dboard_iface::UNIT_RX, dboard_iface::ATR_REG_FULL_DUPLEX, POWER_UP_RXIO | RX_DIS_RXIO);
 }
 
 /***********************************************************************
  * Tuning
  **********************************************************************/
 void xcvr2450::set_lo_freq(double target_freq){
+    //clip for highband and lowband
+    if((target_freq > xcvr_freq_band_seperation.min) and (target_freq < xcvr_freq_band_seperation.max)){
+        if(target_freq - xcvr_freq_band_seperation.min < xcvr_freq_band_seperation.max - target_freq){
+            target_freq = xcvr_freq_band_seperation.min;
+        }else{
+            target_freq = xcvr_freq_band_seperation.max;
+        }
+    }
+
+    //clip for max and min
     target_freq = std::clip(target_freq, xcvr_freq_range.min, xcvr_freq_range.max);
-    //TODO: clip for highband and lowband
 
     //variables used in the calculation below
     double scaler = xcvr2450::is_highband(target_freq)? (4.0/5.0) : (4.0/3.0);
@@ -434,6 +451,114 @@ void xcvr2450::set_rx_gain(float gain, const std::string &name){
     _rx_gains[name] = gain;
 }
 
+
+/***********************************************************************
+ * Bandwidth Handling
+ **********************************************************************/
+static max2829_regs_t::tx_lpf_coarse_adj_t bandwidth_to_tx_lpf_coarse_reg(double &bandwidth){
+    int reg = std::clip(boost::math::iround((bandwidth-6.0e6)/6.0e6), 1, 3);
+
+    switch(reg){
+    case 1: // bandwidth < 15MHz
+        bandwidth = 12e6;
+        return max2829_regs_t::TX_LPF_COARSE_ADJ_12MHZ;
+    case 2: // 15MHz < bandwidth < 21MHz
+        bandwidth = 18e6;
+        return max2829_regs_t::TX_LPF_COARSE_ADJ_18MHZ;
+    case 3: // bandwidth > 21MHz
+        bandwidth = 24e6;
+        return max2829_regs_t::TX_LPF_COARSE_ADJ_24MHZ;
+    }
+    UHD_THROW_INVALID_CODE_PATH();
+}
+
+static max2829_regs_t::rx_lpf_fine_adj_t bandwidth_to_rx_lpf_fine_reg(double &bandwidth, double requested_bandwidth){
+    int reg = std::clip(boost::math::iround((requested_bandwidth/bandwidth)/0.05), 18, 22);
+
+    switch(reg){
+    case 18: // requested_bandwidth < 92.5%
+        bandwidth = 0.9 * bandwidth;
+        return max2829_regs_t::RX_LPF_FINE_ADJ_90;
+    case 19: // 92.5% < requested_bandwidth < 97.5%
+        bandwidth = 0.95 * bandwidth;
+        return max2829_regs_t::RX_LPF_FINE_ADJ_95;
+    case 20: // 97.5% < requested_bandwidth < 102.5%
+        bandwidth = 1.0 * bandwidth;
+        return max2829_regs_t::RX_LPF_FINE_ADJ_100;
+    case 21: // 102.5% < requested_bandwidth < 107.5%
+        bandwidth = 1.05 * bandwidth;
+        return max2829_regs_t::RX_LPF_FINE_ADJ_105;
+    case 22: // 107.5% < requested_bandwidth
+        bandwidth = 1.1 * bandwidth;
+        return max2829_regs_t::RX_LPF_FINE_ADJ_110;
+    }
+    UHD_THROW_INVALID_CODE_PATH();
+}
+
+static max2829_regs_t::rx_lpf_coarse_adj_t bandwidth_to_rx_lpf_coarse_reg(double &bandwidth){
+    int reg = std::clip(boost::math::iround((bandwidth-7.0e6)/1.0e6), 0, 11);
+
+    switch(reg){
+    case 0: // bandwidth < 7.5MHz
+    case 1: // 7.5MHz < bandwidth < 8.5MHz
+        bandwidth = 7.5e6;
+        return max2829_regs_t::RX_LPF_COARSE_ADJ_7_5MHZ;
+    case 2: // 8.5MHz < bandwidth < 9.5MHz
+    case 3: // 9.5MHz < bandwidth < 10.5MHz
+    case 4: // 10.5MHz < bandwidth < 11.5MHz
+        bandwidth = 9.5e6;
+        return max2829_regs_t::RX_LPF_COARSE_ADJ_9_5MHZ;
+    case 5: // 11.5MHz < bandwidth < 12.5MHz
+    case 6: // 12.5MHz < bandwidth < 13.5MHz
+    case 7: // 13.5MHz < bandwidth < 14.5MHz
+    case 8: // 14.5MHz < bandwidth < 15.5MHz
+        bandwidth = 14e6;
+        return max2829_regs_t::RX_LPF_COARSE_ADJ_14MHZ;
+    case 9: // 15.5MHz < bandwidth < 16.5MHz
+    case 10: // 16.5MHz < bandwidth < 17.5MHz
+    case 11: // 17.5MHz < bandwidth
+        bandwidth = 18e6;
+        return max2829_regs_t::RX_LPF_COARSE_ADJ_18MHZ;
+    }
+    UHD_THROW_INVALID_CODE_PATH();
+}
+
+void xcvr2450::set_rx_bandwidth(double bandwidth){
+    double requested_bandwidth = bandwidth;
+
+    //compute coarse low pass cutoff frequency setting
+    _max2829_regs.rx_lpf_coarse_adj = bandwidth_to_rx_lpf_coarse_reg(bandwidth);
+
+    //compute fine low pass cutoff frequency setting
+    _max2829_regs.rx_lpf_fine_adj = bandwidth_to_rx_lpf_fine_reg(bandwidth, requested_bandwidth);
+
+    //shadow bandwidth setting
+    _rx_bandwidth = bandwidth;
+
+    //update register
+    send_reg(0x7);
+
+    if (xcvr2450_debug) std::cerr << boost::format(
+        "XCVR2450 RX Bandwidth (lp_fc): %f Hz, coarse reg: %d, fine reg: %d"
+    ) % _rx_bandwidth % (int(_max2829_regs.rx_lpf_coarse_adj)) % (int(_max2829_regs.rx_lpf_fine_adj)) << std::endl;
+}
+
+void xcvr2450::set_tx_bandwidth(double bandwidth){
+    //compute coarse low pass cutoff frequency setting
+    _max2829_regs.tx_lpf_coarse_adj = bandwidth_to_tx_lpf_coarse_reg(bandwidth);
+
+    //shadow bandwidth setting
+    _tx_bandwidth = bandwidth;
+
+    //update register
+    send_reg(0x7);
+
+    if (xcvr2450_debug) std::cerr << boost::format(
+        "XCVR2450 TX Bandwidth (lp_fc): %f Hz, coarse reg: %d"
+    ) % _tx_bandwidth % (int(_max2829_regs.tx_lpf_coarse_adj)) << std::endl;
+}
+
+
 /***********************************************************************
  * RX Get and Set
  **********************************************************************/
@@ -484,6 +609,10 @@ void xcvr2450::rx_get(const wax::obj &key_, wax::obj &val){
         val = SUBDEV_CONN_COMPLEX_IQ;
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -496,6 +625,10 @@ void xcvr2450::rx_get(const wax::obj &key_, wax::obj &val){
         val = this->get_rssi();
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 2*_rx_bandwidth; //_tx_bandwidth is low-pass, we want complex double-sided
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -518,6 +651,13 @@ void xcvr2450::rx_set(const wax::obj &key_, const wax::obj &val){
         this->set_rx_ant(val.as<std::string>());
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        this->set_rx_bandwidth(val.as<double>()/2.0); //complex double-sided, we want low-pass
+        return;
+
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
@@ -572,6 +712,10 @@ void xcvr2450::tx_get(const wax::obj &key_, wax::obj &val){
         val = SUBDEV_CONN_COMPLEX_QI;
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        val = true; //always enabled
+        return;
+
     case SUBDEV_PROP_USE_LO_OFFSET:
         val = false;
         return;
@@ -580,6 +724,10 @@ void xcvr2450::tx_get(const wax::obj &key_, wax::obj &val){
         val = this->get_locked();
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        val = 2*_tx_bandwidth; //_tx_bandwidth is low-pass, we want complex double-sided
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -598,10 +746,17 @@ void xcvr2450::tx_set(const wax::obj &key_, const wax::obj &val){
         this->set_tx_gain(val.as<float>(), key.name);
         return;
 
+    case SUBDEV_PROP_BANDWIDTH:
+        this->set_tx_bandwidth(val.as<double>()/2.0); //complex double-sided, we want low-pass
+        return;
+
     case SUBDEV_PROP_ANTENNA:
         this->set_tx_ant(val.as<std::string>());
         return;
 
+    case SUBDEV_PROP_ENABLED:
+        return; //always enabled
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
diff --git a/host/lib/usrp/dboard_manager.cpp b/host/lib/usrp/dboard_manager.cpp
index ab80875f5..5a98bb8eb 100644
--- a/host/lib/usrp/dboard_manager.cpp
+++ b/host/lib/usrp/dboard_manager.cpp
@@ -18,6 +18,7 @@
 #include "dboard_ctor_args.hpp"
 #include <uhd/usrp/dboard_manager.hpp>
 #include <uhd/usrp/subdev_props.hpp>
+#include <uhd/utils/warning.hpp>
 #include <uhd/utils/static.hpp>
 #include <uhd/utils/assert.hpp>
 #include <uhd/types/dict.hpp>
@@ -68,24 +69,25 @@ void dboard_manager::register_dboard(
     const prop_names_t &subdev_names
 ){
     //regular registration for ids
-    register_dboard(rx_dboard_id, dboard_ctor, name + " RX", subdev_names);
-    register_dboard(tx_dboard_id, dboard_ctor, name + " TX", subdev_names);
+    register_dboard(rx_dboard_id, dboard_ctor, name, subdev_names);
+    register_dboard(tx_dboard_id, dboard_ctor, name, subdev_names);
 
     //register xcvr mapping for ids
     get_xcvr_id_to_id_map()[rx_dboard_id] = tx_dboard_id;
     get_xcvr_id_to_id_map()[tx_dboard_id] = rx_dboard_id;
 }
 
+std::string dboard_id_t::to_cname(void) const{
+    if (not get_id_to_args_map().has_key(*this)) return "Unknown";
+    return get_id_to_args_map()[*this].get<1>();
+}
+
 std::string dboard_id_t::to_pp_string(void) const{
-    std::string name = "unknown";
-    if (get_id_to_args_map().has_key(*this)){
-        name = get_id_to_args_map()[*this].get<1>();
-    }
-    return str(boost::format("%s (%s)") % name % this->to_string());
+    return str(boost::format("%s (%s)") % this->to_cname() % this->to_string());
 }
 
 /***********************************************************************
- * internal helper classe
+ * internal helper classes
  **********************************************************************/
 /*!
  * A special wax proxy object that forwards calls to a subdev.
@@ -176,10 +178,6 @@ static args_t get_dboard_args(
 ){
     //special case, the none id was provided, use the following ids
     if (dboard_id == dboard_id_t::none() or force_to_unknown){
-        std::cerr << boost::format(
-            "Warning: unknown dboard-id or dboard-id combination: %s\n"
-            "    -> defaulting to the unknown board type"
-        ) % dboard_id.to_pp_string() << std::endl;
         UHD_ASSERT_THROW(get_id_to_args_map().has_key(0xfff1));
         UHD_ASSERT_THROW(get_id_to_args_map().has_key(0xfff0));
         switch(unit){
@@ -191,6 +189,9 @@ static args_t get_dboard_args(
 
     //verify that there is a registered constructor for this id
     if (not get_id_to_args_map().has_key(dboard_id)){
+        uhd::warning::post(str(boost::format(
+            "Unknown dboard ID: %s.\n"
+        ) % dboard_id.to_pp_string()));
         return get_dboard_args(unit, dboard_id, true);
     }
 
@@ -214,12 +215,25 @@ dboard_manager_impl::dboard_manager_impl(
         (get_xcvr_id_to_id_map()[tx_dboard_id] == rx_dboard_id)
     );
 
+    //warn for invalid dboard id xcvr combinations
+    if (rx_dboard_is_xcvr != this_dboard_is_xcvr or tx_dboard_is_xcvr != this_dboard_is_xcvr){
+        uhd::warning::post(str(boost::format(
+            "Unknown transceiver board ID combination...\n"
+            "RX dboard ID: %s\n"
+            "TX dboard ID: %s\n"
+        ) % rx_dboard_id.to_pp_string() % tx_dboard_id.to_pp_string()));
+    }
+
     //extract dboard constructor and settings (force to unknown for messed up xcvr status)
     dboard_ctor_t rx_dboard_ctor; std::string rx_name; prop_names_t rx_subdevs;
-    boost::tie(rx_dboard_ctor, rx_name, rx_subdevs) = get_dboard_args(dboard_iface::UNIT_RX, rx_dboard_id, rx_dboard_is_xcvr != this_dboard_is_xcvr);
+    boost::tie(rx_dboard_ctor, rx_name, rx_subdevs) = get_dboard_args(
+        dboard_iface::UNIT_RX, rx_dboard_id, rx_dboard_is_xcvr != this_dboard_is_xcvr
+    );
 
     dboard_ctor_t tx_dboard_ctor; std::string tx_name; prop_names_t tx_subdevs;
-    boost::tie(tx_dboard_ctor, tx_name, tx_subdevs) = get_dboard_args(dboard_iface::UNIT_TX, tx_dboard_id, tx_dboard_is_xcvr != this_dboard_is_xcvr);
+    boost::tie(tx_dboard_ctor, tx_name, tx_subdevs) = get_dboard_args(
+        dboard_iface::UNIT_TX, tx_dboard_id, tx_dboard_is_xcvr != this_dboard_is_xcvr
+    );
 
     //initialize the gpio pins before creating subdevs
     set_nice_dboard_if();
@@ -317,4 +331,14 @@ void dboard_manager_impl::set_nice_dboard_if(void){
         _iface->set_pin_ctrl(unit, 0x0000); //all gpio
         _iface->set_clock_enabled(unit, false); //clock off
     }
+
+    //disable all rx subdevices
+    BOOST_FOREACH(const std::string &sd_name, this->get_rx_subdev_names()){
+        this->get_rx_subdev(sd_name)[SUBDEV_PROP_ENABLED] = false;
+    }
+
+    //disable all tx subdevices
+    BOOST_FOREACH(const std::string &sd_name, this->get_tx_subdev_names()){
+        this->get_tx_subdev(sd_name)[SUBDEV_PROP_ENABLED] = false;
+    }
 }
diff --git a/host/lib/usrp/mimo_usrp.cpp b/host/lib/usrp/mimo_usrp.cpp
deleted file mode 100644
index 9331c7fbb..000000000
--- a/host/lib/usrp/mimo_usrp.cpp
+++ /dev/null
@@ -1,347 +0,0 @@
-//
-// Copyright 2010 Ettus Research LLC
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-
-#include <uhd/usrp/mimo_usrp.hpp>
-#include <uhd/usrp/tune_helper.hpp>
-#include <uhd/utils/assert.hpp>
-#include <uhd/utils/gain_group.hpp>
-#include <uhd/utils/algorithm.hpp>
-#include <uhd/utils/warning.hpp>
-#include <uhd/usrp/subdev_props.hpp>
-#include <uhd/usrp/mboard_props.hpp>
-#include <uhd/usrp/device_props.hpp>
-#include <uhd/usrp/dboard_props.hpp>
-#include <uhd/usrp/dsp_props.hpp>
-#include <boost/foreach.hpp>
-#include <boost/format.hpp>
-#include <boost/thread.hpp>
-#include <stdexcept>
-#include <iostream>
-
-using namespace uhd;
-using namespace uhd::usrp;
-
-static inline freq_range_t add_dsp_shift(const freq_range_t &range, wax::obj dsp){
-    double codec_rate = dsp[DSP_PROP_CODEC_RATE].as<double>();
-    return freq_range_t(range.min - codec_rate/2.0, range.max + codec_rate/2.0);
-}
-
-/***********************************************************************
- * MIMO USRP Implementation
- **********************************************************************/
-class mimo_usrp_impl : public mimo_usrp{
-public:
-    mimo_usrp_impl(const device_addr_t &addr){
-        _dev = device::make(addr);
-
-        //set the clock config across all mboards (TODO set through api)
-        clock_config_t clock_config;
-        clock_config.ref_source = clock_config_t::REF_SMA;
-        clock_config.pps_source = clock_config_t::PPS_SMA;
-        for (size_t chan = 0; chan < get_num_channels(); chan++){
-            _mboard(chan)[MBOARD_PROP_CLOCK_CONFIG] = clock_config;
-        }
-    }
-
-    ~mimo_usrp_impl(void){
-        /* NOP */
-    }
-
-    device::sptr get_device(void){
-        return _dev;
-    }
-
-    std::string get_pp_string(void){
-        std::string buff = str(boost::format(
-            "MIMO USRP:\n"
-            "  Device: %s\n"
-        )
-            % (*_dev)[DEVICE_PROP_NAME].as<std::string>()
-        );
-        for (size_t chan = 0; chan < get_num_channels(); chan++){
-            buff += str(boost::format(
-                "  Channel: %u\n"
-                "    Mboard: %s\n"
-                "    RX DSP: %s\n"
-                "    RX Dboard: %s\n"
-                "    RX Subdev: %s\n"
-                "    TX DSP: %s\n"
-                "    TX Dboard: %s\n"
-                "    TX Subdev: %s\n"
-            ) % chan
-                % _mboard(chan)[MBOARD_PROP_NAME].as<std::string>()
-                % _rx_dsp(chan)[DSP_PROP_NAME].as<std::string>()
-                % _rx_dboard(chan)[DBOARD_PROP_NAME].as<std::string>()
-                % _rx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>()
-                % _tx_dsp(chan)[DSP_PROP_NAME].as<std::string>()
-                % _tx_dboard(chan)[DBOARD_PROP_NAME].as<std::string>()
-                % _tx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>()
-            );
-        }
-        return buff;
-    }
-
-    size_t get_num_channels(void){
-        return (*_dev)[DEVICE_PROP_MBOARD_NAMES].as<prop_names_t>().size();
-    }
-
-    /*******************************************************************
-     * Misc
-     ******************************************************************/
-    time_spec_t get_time_now(void){
-        //the time on the first mboard better be the same on all
-        return _mboard(0)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
-    }
-
-    void set_time_next_pps(const time_spec_t &time_spec){
-        for (size_t chan = 0; chan < get_num_channels(); chan++){
-            _mboard(chan)[MBOARD_PROP_TIME_NEXT_PPS] = time_spec;
-        }
-    }
-
-    void set_time_unknown_pps(const time_spec_t &time_spec){
-        std::cout << "Set time with unknown pps edge:" << std::endl;
-        std::cout << "    1) set times next pps (race condition)" << std::endl;
-        set_time_next_pps(time_spec);
-        boost::this_thread::sleep(boost::posix_time::seconds(1));
-
-        std::cout << "    2) catch seconds rollover at pps edge" << std::endl;
-        time_t last_secs = 0, curr_secs = 0;
-        while(curr_secs == last_secs){
-            last_secs = curr_secs;
-            curr_secs = get_time_now().get_full_secs();
-        }
-
-        std::cout << "    3) set times next pps (synchronously)" << std::endl;
-        set_time_next_pps(time_spec);
-        boost::this_thread::sleep(boost::posix_time::seconds(1));
-
-        //verify that the time registers are read to be within a few RTT
-        for (size_t chan = 1; chan < get_num_channels(); chan++){
-            time_spec_t time_0 = _mboard(0)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
-            time_spec_t time_i = _mboard(chan)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
-            if (time_i < time_0 or (time_i - time_0) > time_spec_t(0.01)){ //10 ms: greater than RTT but not too big
-                uhd::print_warning(str(boost::format(
-                    "Detected time deviation between board %d and board 0.\n"
-                    "Board 0 time is %f seconds.\n"
-                    "Board %d time is %f seconds.\n"
-                ) % chan % time_0.get_real_secs() % chan % time_i.get_real_secs()));
-            }
-        }
-    }
-
-    void issue_stream_cmd(const stream_cmd_t &stream_cmd){
-        for (size_t chan = 0; chan < get_num_channels(); chan++){
-            _mboard(chan)[MBOARD_PROP_STREAM_CMD] = stream_cmd;
-        }
-    }
-
-    /*******************************************************************
-     * RX methods
-     ******************************************************************/
-    void set_rx_subdev_spec(size_t chan, const subdev_spec_t &spec){
-        UHD_ASSERT_THROW(spec.size() <= 1);
-        _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC] = spec;
-    }
-
-    subdev_spec_t get_rx_subdev_spec(size_t chan){
-        return _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>();
-    }
-
-    void set_rx_rate_all(double rate){
-        std::vector<double> _actual_rates;
-        for (size_t chan = 0; chan < get_num_channels(); chan++){
-            _rx_dsp(chan)[DSP_PROP_HOST_RATE] = rate;
-            _actual_rates.push_back(_rx_dsp(chan)[DSP_PROP_HOST_RATE].as<double>());
-        }
-        _rx_rate = _actual_rates.front();
-        if (std::count(_actual_rates, _rx_rate) != _actual_rates.size()) throw std::runtime_error(
-            "MIMO configuratio error: rx rate inconsistent across mboards"
-        );
-    }
-
-    double get_rx_rate_all(void){
-        return _rx_rate;
-    }
-
-    tune_result_t set_rx_freq(size_t chan, double target_freq){
-        return tune_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(chan), 0, target_freq);
-    }
-
-    tune_result_t set_rx_freq(size_t chan, double target_freq, double lo_off){
-        return tune_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(chan), 0, target_freq, lo_off);
-    }
-
-    double get_rx_freq(size_t chan){
-        return derive_freq_from_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(chan), 0);
-    }
-
-    freq_range_t get_rx_freq_range(size_t chan){
-        return add_dsp_shift(_rx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _rx_dsp(chan));
-    }
-
-    void set_rx_gain(size_t chan, float gain){
-        return _rx_gain_group(chan)->set_value(gain);
-    }
-
-    float get_rx_gain(size_t chan){
-        return _rx_gain_group(chan)->get_value();
-    }
-
-    gain_range_t get_rx_gain_range(size_t chan){
-        return _rx_gain_group(chan)->get_range();
-    }
-
-    void set_rx_antenna(size_t chan, const std::string &ant){
-        _rx_subdev(chan)[SUBDEV_PROP_ANTENNA] = ant;
-    }
-
-    std::string get_rx_antenna(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_ANTENNA].as<std::string>();
-    }
-
-    std::vector<std::string> get_rx_antennas(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_ANTENNA_NAMES].as<prop_names_t>();
-    }
-
-    bool get_rx_lo_locked(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
-    }
-
-    float read_rssi(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_RSSI].as<float>();
-    }
-
-    /*******************************************************************
-     * TX methods
-     ******************************************************************/
-    void set_tx_subdev_spec(size_t chan, const subdev_spec_t &spec){
-        UHD_ASSERT_THROW(spec.size() <= 1);
-        _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC] = spec;
-    }
-
-    subdev_spec_t get_tx_subdev_spec(size_t chan){
-        return _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>();
-    }
-
-    void set_tx_rate_all(double rate){
-        std::vector<double> _actual_rates;
-        for (size_t chan = 0; chan < get_num_channels(); chan++){
-            _tx_dsp(chan)[DSP_PROP_HOST_RATE] = rate;
-            _actual_rates.push_back(_tx_dsp(chan)[DSP_PROP_HOST_RATE].as<double>());
-        }
-        _tx_rate = _actual_rates.front();
-        if (std::count(_actual_rates, _tx_rate) != _actual_rates.size()) throw std::runtime_error(
-            "MIMO configuratio error: tx rate inconsistent across mboards"
-        );
-    }
-
-    double get_tx_rate_all(void){
-        return _tx_rate;
-    }
-
-    tune_result_t set_tx_freq(size_t chan, double target_freq){
-        return tune_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(chan), 0, target_freq);
-    }
-
-    tune_result_t set_tx_freq(size_t chan, double target_freq, double lo_off){
-        return tune_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(chan), 0, target_freq, lo_off);
-    }
-
-    double get_tx_freq(size_t chan){
-        return derive_freq_from_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(chan), 0);
-    }
-
-    freq_range_t get_tx_freq_range(size_t chan){
-        return add_dsp_shift(_tx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _tx_dsp(chan));
-    }
-
-    void set_tx_gain(size_t chan, float gain){
-        return _tx_gain_group(chan)->set_value(gain);
-    }
-
-    float get_tx_gain(size_t chan){
-        return _tx_gain_group(chan)->get_value();
-    }
-
-    gain_range_t get_tx_gain_range(size_t chan){
-        return _tx_gain_group(chan)->get_range();
-    }
-
-    void set_tx_antenna(size_t chan, const std::string &ant){
-        _tx_subdev(chan)[SUBDEV_PROP_ANTENNA] = ant;
-    }
-
-    std::string get_tx_antenna(size_t chan){
-        return _tx_subdev(chan)[SUBDEV_PROP_ANTENNA].as<std::string>();
-    }
-
-    std::vector<std::string> get_tx_antennas(size_t chan){
-        return _tx_subdev(chan)[SUBDEV_PROP_ANTENNA_NAMES].as<prop_names_t>();
-    }
-
-    bool get_tx_lo_locked(size_t chan){
-        return _tx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
-    }
-
-private:
-    device::sptr _dev;
-    wax::obj _mboard(size_t chan){
-        prop_names_t names = (*_dev)[DEVICE_PROP_MBOARD_NAMES].as<prop_names_t>();
-        return (*_dev)[named_prop_t(DEVICE_PROP_MBOARD, names.at(chan))];
-    }
-    wax::obj _rx_dsp(size_t chan){
-        return _mboard(chan)[MBOARD_PROP_RX_DSP];
-    }
-    wax::obj _tx_dsp(size_t chan){
-        return _mboard(chan)[MBOARD_PROP_TX_DSP];
-    }
-    wax::obj _rx_dboard(size_t chan){
-        std::string db_name = _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>().front().db_name;
-        return _mboard(chan)[named_prop_t(MBOARD_PROP_RX_DBOARD, db_name)];
-    }
-    wax::obj _tx_dboard(size_t chan){
-        std::string db_name = _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>().front().db_name;
-        return _mboard(chan)[named_prop_t(MBOARD_PROP_TX_DBOARD, db_name)];
-    }
-    wax::obj _rx_subdev(size_t chan){
-        std::string sd_name = _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>().front().sd_name;
-        return _rx_dboard(chan)[named_prop_t(DBOARD_PROP_SUBDEV, sd_name)];
-    }
-    wax::obj _tx_subdev(size_t chan){
-        std::string sd_name = _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>().front().sd_name;
-        return _tx_dboard(chan)[named_prop_t(DBOARD_PROP_SUBDEV, sd_name)];
-    }
-    gain_group::sptr _rx_gain_group(size_t chan){
-        std::string sd_name = _mboard(chan)[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>().front().sd_name;
-        return _rx_dboard(chan)[named_prop_t(DBOARD_PROP_GAIN_GROUP, sd_name)].as<gain_group::sptr>();
-    }
-    gain_group::sptr _tx_gain_group(size_t chan){
-        std::string sd_name = _mboard(chan)[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>().front().sd_name;
-        return _tx_dboard(chan)[named_prop_t(DBOARD_PROP_GAIN_GROUP, sd_name)].as<gain_group::sptr>();
-    }
-
-    //shadows
-    double _rx_rate, _tx_rate;
-};
-
-/***********************************************************************
- * The Make Function
- **********************************************************************/
-mimo_usrp::sptr mimo_usrp::make(const device_addr_t &dev_addr){
-    return sptr(new mimo_usrp_impl(dev_addr));
-}
diff --git a/host/lib/usrp/misc_utils.cpp b/host/lib/usrp/misc_utils.cpp
index 5cfcdc8d3..5856d706f 100644
--- a/host/lib/usrp/misc_utils.cpp
+++ b/host/lib/usrp/misc_utils.cpp
@@ -17,6 +17,7 @@
 
 #include <uhd/usrp/misc_utils.hpp>
 #include <uhd/utils/assert.hpp>
+#include <uhd/utils/algorithm.hpp>
 #include <uhd/utils/gain_group.hpp>
 #include <uhd/usrp/dboard_id.hpp>
 #include <uhd/usrp/subdev_props.hpp>
@@ -79,6 +80,7 @@ static void set_subdev_gain(wax::obj subdev, const std::string &name, float gain
  * gain group factory function for usrp
  **********************************************************************/
 gain_group::sptr usrp::make_gain_group(
+    const dboard_id_t &dboard_id,
     wax::obj subdev, wax::obj codec,
     gain_group_policy_t gain_group_policy
 ){
@@ -86,6 +88,8 @@ gain_group::sptr usrp::make_gain_group(
     const size_t codec_gain_priority = (gain_group_policy == GAIN_GROUP_POLICY_RX)?
         (subdev_gain_priority - 1): //RX policy, codec gains fill last (lower priority)
         (subdev_gain_priority + 1); //TX policy, codec gains fill first (higher priority)
+    const std::string subdev_prefix = dboard_id.to_cname() + "-";
+    const std::string codec_prefix = (gain_group_policy == GAIN_GROUP_POLICY_RX)? "ADC-" : "DAC-";
 
     gain_group::sptr gg = gain_group::make();
     gain_fcns_t fcns;
@@ -94,7 +98,7 @@ gain_group::sptr usrp::make_gain_group(
         fcns.get_range = boost::bind(&get_subdev_gain_range, subdev, name);
         fcns.get_value = boost::bind(&get_subdev_gain, subdev, name);
         fcns.set_value = boost::bind(&set_subdev_gain, subdev, name, _1);
-        gg->register_fcns(fcns, subdev_gain_priority);
+        gg->register_fcns(subdev_prefix+name, fcns, subdev_gain_priority);
     }
     //add all the codec gains last (antenna to dsp order)
     BOOST_FOREACH(const std::string &name, codec[CODEC_PROP_GAIN_NAMES].as<prop_names_t>()){
@@ -118,7 +122,7 @@ gain_group::sptr usrp::make_gain_group(
             fcns.set_value = boost::bind(&set_codec_gain_q, codec, name, _1);
             break;
         }
-        gg->register_fcns(fcns, codec_gain_priority);
+        gg->register_fcns(codec_prefix+name, fcns, codec_gain_priority);
     }
     return gg;
 }
@@ -160,13 +164,13 @@ static void verify_xx_subdev_spec(
         }
 
         //sanity check that the dboard/subdevice names exist for this mboard
-        BOOST_FOREACH(const subdev_spec_pair_t &pair, subdev_spec){
+        BOOST_FOREACH(subdev_spec_pair_t &pair, subdev_spec){
             //empty db name means select dboard automatically
             if (pair.db_name.empty()){
                 if (dboard_names.size() != 1) throw std::runtime_error(
                     "A daughterboard name must be provided for multi-slot motherboards: " + subdev_spec.to_string()
                 );
-                pair.db_name == dboard_names.front();
+                pair.db_name = dboard_names.front();
             }
             uhd::assert_has(dboard_names, pair.db_name, xx_type + " dboard name");
             wax::obj dboard = mboard[named_prop_t(dboard_prop, pair.db_name)];
@@ -177,7 +181,7 @@ static void verify_xx_subdev_spec(
                 if (subdev_names.size() != 1) throw std::runtime_error(
                     "A subdevice name must be provided for multi-subdev daughterboards: " + subdev_spec.to_string()
                 );
-                pair.sd_name == subdev_names.front();
+                pair.sd_name = subdev_names.front();
             }
             uhd::assert_has(subdev_names, pair.sd_name, xx_type + " subdev name");
         }
@@ -186,6 +190,22 @@ static void verify_xx_subdev_spec(
             "Validate %s subdev spec failed: %s\n    %s"
         ) % xx_type % subdev_spec.to_string() % e.what()));
     }
+
+    //now use the subdev spec to enable the subdevices in use and vice-versa
+    BOOST_FOREACH(const std::string &db_name, mboard[dboard_names_prop].as<prop_names_t>()){
+        wax::obj dboard = mboard[named_prop_t(dboard_prop, db_name)];
+        BOOST_FOREACH(const std::string &sd_name, dboard[DBOARD_PROP_SUBDEV_NAMES].as<prop_names_t>()){
+            try{
+                bool enable = std::has(subdev_spec, subdev_spec_pair_t(db_name, sd_name));
+                dboard[named_prop_t(DBOARD_PROP_SUBDEV, sd_name)][SUBDEV_PROP_ENABLED] = enable;
+            }
+            catch(const std::exception &e){
+                throw std::runtime_error(str(boost::format(
+                    "Cannot set enabled property on subdevice %s:%s\n    %s"
+                ) % db_name % sd_name % e.what()));
+            }
+        }
+    }
 }
 
 void usrp::verify_rx_subdev_spec(subdev_spec_t &subdev_spec, wax::obj mboard){
diff --git a/host/lib/usrp/multi_usrp.cpp b/host/lib/usrp/multi_usrp.cpp
new file mode 100644
index 000000000..876f1a3fc
--- /dev/null
+++ b/host/lib/usrp/multi_usrp.cpp
@@ -0,0 +1,442 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "wrapper_utils.hpp"
+#include <uhd/usrp/multi_usrp.hpp>
+#include <uhd/usrp/tune_helper.hpp>
+#include <uhd/utils/assert.hpp>
+#include <uhd/utils/warning.hpp>
+#include <uhd/utils/gain_group.hpp>
+#include <uhd/usrp/subdev_props.hpp>
+#include <uhd/usrp/mboard_props.hpp>
+#include <uhd/usrp/device_props.hpp>
+#include <uhd/usrp/dboard_props.hpp>
+#include <uhd/usrp/dsp_props.hpp>
+#include <boost/thread.hpp>
+#include <boost/foreach.hpp>
+#include <boost/format.hpp>
+#include <stdexcept>
+#include <iostream>
+
+using namespace uhd;
+using namespace uhd::usrp;
+
+const std::string multi_usrp::ALL_GAINS = "";
+
+/***********************************************************************
+ * Simple USRP Implementation
+ **********************************************************************/
+class multi_usrp_impl : public multi_usrp{
+public:
+    multi_usrp_impl(const device_addr_t &addr){
+        _dev = device::make(addr);
+    }
+
+    device::sptr get_device(void){
+        return _dev;
+    }
+
+    /*******************************************************************
+     * Mboard methods
+     ******************************************************************/
+    std::string get_pp_string(void){
+        std::string buff = str(boost::format(
+            "Multi USRP:\n"
+            "  Device: %s\n"
+        )
+            % (*_dev)[DEVICE_PROP_NAME].as<std::string>()
+        );
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            buff += str(boost::format(
+                "  Mboard %d: %s\n"
+            ) % m
+                % _mboard(m)[MBOARD_PROP_NAME].as<std::string>()
+            );
+        }
+
+        //----------- rx side of life ----------------------------------
+        for (size_t m = 0, chan = 0; m < get_num_mboards(); m++){
+            buff += str(boost::format(
+                "  RX DSP %d: %s\n"
+            ) % m
+                % _rx_dsp(m)[DSP_PROP_NAME].as<std::string>()
+            );
+            for (; chan < (m + 1)*get_rx_subdev_spec(m).size(); chan++){
+                buff += str(boost::format(
+                    "  RX Channel: %u\n"
+                    "    RX Dboard: %s\n"
+                    "    RX Subdev: %s\n"
+                ) % chan
+                    % _rx_dboard(chan)[DBOARD_PROP_NAME].as<std::string>()
+                    % _rx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>()
+                );
+            }
+        }
+
+        //----------- tx side of life ----------------------------------
+        for (size_t m = 0, chan = 0; m < get_num_mboards(); m++){
+            buff += str(boost::format(
+                "  TX DSP %d: %s\n"
+            ) % m
+                % _tx_dsp(m)[DSP_PROP_NAME].as<std::string>()
+            );
+            for (; chan < (m + 1)*get_tx_subdev_spec(m).size(); chan++){
+                buff += str(boost::format(
+                    "  TX Channel: %u\n"
+                    "    TX Dboard: %s\n"
+                    "    TX Subdev: %s\n"
+                ) % chan
+                    % _tx_dboard(chan)[DBOARD_PROP_NAME].as<std::string>()
+                    % _tx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>()
+                );
+            }
+        }
+
+        return buff;
+    }
+
+    std::string get_mboard_name(size_t mboard){
+        return _mboard(mboard)[MBOARD_PROP_NAME].as<std::string>();
+    }
+
+    time_spec_t get_time_now(void){
+        return _mboard(0)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
+    }
+
+    void set_time_next_pps(const time_spec_t &time_spec){
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            _mboard(m)[MBOARD_PROP_TIME_NEXT_PPS] = time_spec;
+        }
+    }
+
+    void set_time_unknown_pps(const time_spec_t &time_spec){
+        std::cout << "Set time with unknown pps edge:" << std::endl;
+        std::cout << "    1) set times next pps (race condition)" << std::endl;
+        set_time_next_pps(time_spec);
+        boost::this_thread::sleep(boost::posix_time::seconds(1));
+
+        std::cout << "    2) catch seconds rollover at pps edge" << std::endl;
+        time_t last_secs = 0, curr_secs = 0;
+        while(curr_secs == last_secs){
+            last_secs = curr_secs;
+            curr_secs = get_time_now().get_full_secs();
+        }
+
+        std::cout << "    3) set times next pps (synchronously)" << std::endl;
+        set_time_next_pps(time_spec);
+        boost::this_thread::sleep(boost::posix_time::seconds(1));
+
+        //verify that the time registers are read to be within a few RTT
+        for (size_t m = 1; m < get_num_mboards(); m++){
+            time_spec_t time_0 = _mboard(0)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
+            time_spec_t time_i = _mboard(m)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
+            if (time_i < time_0 or (time_i - time_0) > time_spec_t(0.01)){ //10 ms: greater than RTT but not too big
+                uhd::warning::post(str(boost::format(
+                    "Detected time deviation between board %d and board 0.\n"
+                    "Board 0 time is %f seconds.\n"
+                    "Board %d time is %f seconds.\n"
+                ) % m % time_0.get_real_secs() % m % time_i.get_real_secs()));
+            }
+        }
+    }
+
+    bool get_time_synchronized(void){
+        for (size_t m = 1; m < get_num_mboards(); m++){
+            time_spec_t time_0 = _mboard(0)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
+            time_spec_t time_i = _mboard(m)[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
+            if (time_i < time_0 or (time_i - time_0) > time_spec_t(0.01)) return false;
+        }
+        return true;
+    }
+
+    void issue_stream_cmd(const stream_cmd_t &stream_cmd){
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            _mboard(m)[MBOARD_PROP_STREAM_CMD] = stream_cmd;
+        }
+    }
+
+    void set_clock_config(const clock_config_t &clock_config, size_t mboard){
+        if (mboard != ALL_MBOARDS){
+            _mboard(mboard)[MBOARD_PROP_CLOCK_CONFIG] = clock_config;
+            return;
+        }
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            set_clock_config(clock_config, m);
+        }
+    }
+
+    size_t get_num_mboards(void){
+        return (*_dev)[DEVICE_PROP_MBOARD_NAMES].as<prop_names_t>().size();
+    }
+
+    /*******************************************************************
+     * RX methods
+     ******************************************************************/
+    void set_rx_subdev_spec(const subdev_spec_t &spec, size_t mboard){
+        if (mboard != ALL_MBOARDS){
+            _mboard(mboard)[MBOARD_PROP_RX_SUBDEV_SPEC] = spec;
+            return;
+        }
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            set_rx_subdev_spec(spec, m);
+        }
+    }
+
+    subdev_spec_t get_rx_subdev_spec(size_t mboard){
+        return _mboard(mboard)[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>();
+    }
+
+    size_t get_rx_num_channels(void){
+        return rx_cpm()*get_num_mboards(); //total num channels
+    }
+
+    std::string get_rx_subdev_name(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>();
+    }
+
+    void set_rx_rate(double rate){
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            _rx_dsp(m)[DSP_PROP_HOST_RATE] = rate;
+        }
+        do_samp_rate_warning_message(rate, get_rx_rate(), "RX");
+    }
+
+    double get_rx_rate(void){
+        return _rx_dsp(0)[DSP_PROP_HOST_RATE].as<double>();
+    }
+
+    tune_result_t set_rx_freq(const tune_request_t &tune_request, size_t chan){
+        tune_result_t r = tune_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(chan/rx_cpm()), chan%rx_cpm(), tune_request);
+        do_tune_freq_warning_message(tune_request.target_freq, get_rx_freq(chan), "RX");
+        return r;
+    }
+
+    double get_rx_freq(size_t chan){
+        return derive_freq_from_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(chan/rx_cpm()), chan%rx_cpm());
+    }
+
+    freq_range_t get_rx_freq_range(size_t chan){
+        return add_dsp_shift(_rx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _rx_dsp(chan/rx_cpm()));
+    }
+
+    void set_rx_gain(float gain, const std::string &name, size_t chan){
+        return _rx_gain_group(chan)->set_value(gain, name);
+    }
+
+    float get_rx_gain(const std::string &name, size_t chan){
+        return _rx_gain_group(chan)->get_value(name);
+    }
+
+    gain_range_t get_rx_gain_range(const std::string &name, size_t chan){
+        return _rx_gain_group(chan)->get_range(name);
+    }
+
+    std::vector<std::string> get_rx_gain_names(size_t chan){
+        return _rx_gain_group(chan)->get_names();
+    }
+
+    void set_rx_antenna(const std::string &ant, size_t chan){
+        _rx_subdev(chan)[SUBDEV_PROP_ANTENNA] = ant;
+    }
+
+    std::string get_rx_antenna(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_ANTENNA].as<std::string>();
+    }
+
+    std::vector<std::string> get_rx_antennas(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_ANTENNA_NAMES].as<prop_names_t>();
+    }
+
+    bool get_rx_lo_locked(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
+    }
+
+    void set_rx_bandwidth(double bandwidth, size_t chan){
+        _rx_subdev(chan)[SUBDEV_PROP_BANDWIDTH] = bandwidth;
+    }
+
+    double get_rx_bandwidth(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_BANDWIDTH].as<double>();
+    }
+
+    float read_rssi(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_RSSI].as<float>();
+    }
+
+    dboard_iface::sptr get_rx_dboard_iface(size_t chan){
+        return _rx_dboard(chan)[DBOARD_PROP_DBOARD_IFACE].as<dboard_iface::sptr>();
+    }
+
+    /*******************************************************************
+     * TX methods
+     ******************************************************************/
+    void set_tx_subdev_spec(const subdev_spec_t &spec, size_t mboard){
+        if (mboard != ALL_MBOARDS){
+            _mboard(mboard)[MBOARD_PROP_TX_SUBDEV_SPEC] = spec;
+            return;
+        }
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            set_tx_subdev_spec(spec, m);
+        }
+    }
+
+    subdev_spec_t get_tx_subdev_spec(size_t mboard){
+        return _mboard(mboard)[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>();
+    }
+
+    std::string get_tx_subdev_name(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>();
+    }
+
+    size_t get_tx_num_channels(void){
+        return tx_cpm()*get_num_mboards(); //total num channels
+    }
+
+    void set_tx_rate(double rate){
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            _tx_dsp(m)[DSP_PROP_HOST_RATE] = rate;
+        }
+        do_samp_rate_warning_message(rate, get_tx_rate(), "TX");
+    }
+
+    double get_tx_rate(void){
+        return _tx_dsp(0)[DSP_PROP_HOST_RATE].as<double>();
+    }
+
+    tune_result_t set_tx_freq(const tune_request_t &tune_request, size_t chan){
+        tune_result_t r = tune_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(chan/tx_cpm()), chan%tx_cpm(), tune_request);
+        do_tune_freq_warning_message(tune_request.target_freq, get_tx_freq(chan), "TX");
+        return r;
+    }
+
+    double get_tx_freq(size_t chan){
+        return derive_freq_from_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(chan/tx_cpm()), chan%tx_cpm());
+    }
+
+    freq_range_t get_tx_freq_range(size_t chan){
+        return add_dsp_shift(_tx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _tx_dsp(chan/tx_cpm()));
+    }
+
+    void set_tx_gain(float gain, const std::string &name, size_t chan){
+        return _tx_gain_group(chan)->set_value(gain, name);
+    }
+
+    float get_tx_gain(const std::string &name, size_t chan){
+        return _tx_gain_group(chan)->get_value(name);
+    }
+
+    gain_range_t get_tx_gain_range(const std::string &name, size_t chan){
+        return _tx_gain_group(chan)->get_range(name);
+    }
+
+    std::vector<std::string> get_tx_gain_names(size_t chan){
+        return _tx_gain_group(chan)->get_names();
+    }
+
+    void set_tx_antenna(const std::string &ant, size_t chan){
+        _tx_subdev(chan)[SUBDEV_PROP_ANTENNA] = ant;
+    }
+
+    std::string get_tx_antenna(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_ANTENNA].as<std::string>();
+    }
+
+    std::vector<std::string> get_tx_antennas(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_ANTENNA_NAMES].as<prop_names_t>();
+    }
+
+    bool get_tx_lo_locked(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
+    }
+
+    void set_tx_bandwidth(double bandwidth, size_t chan){
+        _tx_subdev(chan)[SUBDEV_PROP_BANDWIDTH] = bandwidth;
+    }
+
+    double get_tx_bandwidth(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_BANDWIDTH].as<double>();
+    }
+
+    dboard_iface::sptr get_tx_dboard_iface(size_t chan){
+        return _tx_dboard(chan)[DBOARD_PROP_DBOARD_IFACE].as<dboard_iface::sptr>();
+    }
+
+private:
+    device::sptr _dev;
+
+    size_t rx_cpm(void){ //channels per mboard
+        size_t nchan = get_rx_subdev_spec(0).size();
+        for (size_t m = 1; m < get_num_mboards(); m++){
+            if (nchan != get_rx_subdev_spec(m).size()){
+                throw std::runtime_error("rx subdev spec size inconsistent across all mboards");
+            }
+        }
+        return nchan;
+    }
+
+    size_t tx_cpm(void){ //channels per mboard
+        size_t nchan = get_tx_subdev_spec(0).size();
+        for (size_t m = 1; m < get_num_mboards(); m++){
+            if (nchan != get_tx_subdev_spec(m).size()){
+                throw std::runtime_error("tx subdev spec size inconsistent across all mboards");
+            }
+        }
+        return nchan;
+    }
+
+    wax::obj _mboard(size_t mboard){
+        std::string mb_name = (*_dev)[DEVICE_PROP_MBOARD_NAMES].as<prop_names_t>().at(mboard);
+        return (*_dev)[named_prop_t(DEVICE_PROP_MBOARD, mb_name)];
+    }
+    wax::obj _rx_dsp(size_t mboard){
+        return _mboard(mboard)[MBOARD_PROP_RX_DSP];
+    }
+    wax::obj _tx_dsp(size_t mboard){
+        return _mboard(mboard)[MBOARD_PROP_TX_DSP];
+    }
+    wax::obj _rx_dboard(size_t chan){
+        std::string db_name = get_rx_subdev_spec(chan/rx_cpm()).at(chan%rx_cpm()).db_name;
+        return _mboard(chan/rx_cpm())[named_prop_t(MBOARD_PROP_RX_DBOARD, db_name)];
+    }
+    wax::obj _tx_dboard(size_t chan){
+        std::string db_name = get_tx_subdev_spec(chan/tx_cpm()).at(chan%tx_cpm()).db_name;
+        return _mboard(chan/tx_cpm())[named_prop_t(MBOARD_PROP_TX_DBOARD, db_name)];
+    }
+    wax::obj _rx_subdev(size_t chan){
+        std::string sd_name = get_rx_subdev_spec(chan/rx_cpm()).at(chan%rx_cpm()).sd_name;
+        return _rx_dboard(chan)[named_prop_t(DBOARD_PROP_SUBDEV, sd_name)];
+    }
+    wax::obj _tx_subdev(size_t chan){
+        std::string sd_name = get_tx_subdev_spec(chan/tx_cpm()).at(chan%tx_cpm()).sd_name;
+        return _tx_dboard(chan)[named_prop_t(DBOARD_PROP_SUBDEV, sd_name)];
+    }
+    gain_group::sptr _rx_gain_group(size_t chan){
+        std::string sd_name = get_rx_subdev_spec(chan/rx_cpm()).at(chan%rx_cpm()).sd_name;
+        return _rx_dboard(chan)[named_prop_t(DBOARD_PROP_GAIN_GROUP, sd_name)].as<gain_group::sptr>();
+    }
+    gain_group::sptr _tx_gain_group(size_t chan){
+        std::string sd_name = get_tx_subdev_spec(chan/tx_cpm()).at(chan%tx_cpm()).sd_name;
+        return _tx_dboard(chan)[named_prop_t(DBOARD_PROP_GAIN_GROUP, sd_name)].as<gain_group::sptr>();
+    }
+};
+
+/***********************************************************************
+ * The Make Function
+ **********************************************************************/
+multi_usrp::sptr multi_usrp::make(const device_addr_t &dev_addr){
+    return sptr(new multi_usrp_impl(dev_addr));
+}
diff --git a/host/lib/usrp/simple_usrp.cpp b/host/lib/usrp/simple_usrp.cpp
deleted file mode 100644
index b89b76eed..000000000
--- a/host/lib/usrp/simple_usrp.cpp
+++ /dev/null
@@ -1,222 +0,0 @@
-//
-// Copyright 2010 Ettus Research LLC
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-
-#include <uhd/usrp/single_usrp.hpp>
-#include <uhd/usrp/simple_usrp.hpp>
-#include <uhd/utils/warning.hpp>
-
-using namespace uhd;
-using namespace uhd::usrp;
-
-/***********************************************************************
- * Simple USRP Implementation
- **********************************************************************/
-class simple_usrp_impl : public simple_usrp{
-public:
-    simple_usrp_impl(const device_addr_t &addr){
-        _sdev = single_usrp::make(addr);
-    }
-
-    ~simple_usrp_impl(void){
-        /* NOP */
-    }
-
-    device::sptr get_device(void){
-        return _sdev->get_device();
-    }
-
-    std::string get_pp_string(void){
-        return _sdev->get_pp_string();
-    }
-
-    /*******************************************************************
-     * Misc
-     ******************************************************************/
-    time_spec_t get_time_now(void){
-        return _sdev->get_time_now();
-    }
-
-    void set_time_now(const time_spec_t &time_spec){
-        return _sdev->set_time_now(time_spec);
-    }
-
-    void set_time_next_pps(const time_spec_t &time_spec){
-        return _sdev->set_time_next_pps(time_spec);
-    }
-
-    void issue_stream_cmd(const stream_cmd_t &stream_cmd){
-        return _sdev->issue_stream_cmd(stream_cmd);
-    }
-
-    void set_clock_config(const clock_config_t &clock_config){
-        return _sdev->set_clock_config(clock_config);
-    }
-
-    /*******************************************************************
-     * RX methods
-     ******************************************************************/
-    void set_rx_subdev_spec(const subdev_spec_t &spec){
-        return _sdev->set_rx_subdev_spec(spec);
-    }
-
-    subdev_spec_t get_rx_subdev_spec(void){
-        return _sdev->get_rx_subdev_spec();
-    }
-
-    void set_rx_rate(double rate){
-        return _sdev->set_rx_rate(rate);
-    }
-
-    double get_rx_rate(void){
-        return _sdev->get_rx_rate();
-    }
-
-    tune_result_t set_rx_freq(double target_freq){
-        return _sdev->set_rx_freq(target_freq);
-    }
-
-    tune_result_t set_rx_freq(double target_freq, double lo_off){
-        return _sdev->set_rx_freq(target_freq, lo_off);
-    }
-
-    double get_rx_freq(void){
-        return _sdev->get_rx_freq();
-    }
-
-    freq_range_t get_rx_freq_range(void){
-        return _sdev->get_rx_freq_range();
-    }
-
-    void set_rx_gain(float gain){
-        return _sdev->set_rx_gain(gain);
-    }
-
-    float get_rx_gain(void){
-        return _sdev->get_rx_gain();
-    }
-
-    gain_range_t get_rx_gain_range(void){
-        return _sdev->get_rx_gain_range();
-    }
-
-    void set_rx_antenna(const std::string &ant){
-        return _sdev->set_rx_antenna(ant);
-    }
-
-    std::string get_rx_antenna(void){
-        return _sdev->get_rx_antenna();
-    }
-
-    std::vector<std::string> get_rx_antennas(void){
-        return _sdev->get_rx_antennas();
-    }
-
-    bool get_rx_lo_locked(void){
-        return _sdev->get_rx_lo_locked();
-    }
-
-    float read_rssi(void){
-        return _sdev->read_rssi();
-    }
-
-    dboard_iface::sptr get_rx_dboard_iface(void){
-        return _sdev->get_rx_dboard_iface();
-    }
-
-    /*******************************************************************
-     * TX methods
-     ******************************************************************/
-    void set_tx_subdev_spec(const subdev_spec_t &spec){
-        return _sdev->set_tx_subdev_spec(spec);
-    }
-
-    subdev_spec_t get_tx_subdev_spec(void){
-        return _sdev->get_tx_subdev_spec();
-    }
-
-    void set_tx_rate(double rate){
-        return _sdev->set_tx_rate(rate);
-    }
-
-    double get_tx_rate(void){
-        return _sdev->get_tx_rate();
-    }
-
-    tune_result_t set_tx_freq(double target_freq){
-        return _sdev->set_tx_freq(target_freq);
-    }
-
-    tune_result_t set_tx_freq(double target_freq, double lo_off){
-        return _sdev->set_tx_freq(target_freq, lo_off);
-    }
-
-    double get_tx_freq(void){
-        return _sdev->get_tx_freq();
-    }
-
-    freq_range_t get_tx_freq_range(void){
-        return _sdev->get_tx_freq_range();
-    }
-
-    void set_tx_gain(float gain){
-        return _sdev->set_tx_gain(gain);
-    }
-
-    float get_tx_gain(void){
-        return _sdev->get_tx_gain();
-    }
-
-    gain_range_t get_tx_gain_range(void){
-        return _sdev->get_tx_gain_range();
-    }
-
-    void set_tx_antenna(const std::string &ant){
-        return _sdev->set_tx_antenna(ant);
-    }
-
-    std::string get_tx_antenna(void){
-        return _sdev->get_tx_antenna();
-    }
-
-    std::vector<std::string> get_tx_antennas(void){
-        return _sdev->get_tx_antennas();
-    }
-
-    bool get_tx_lo_locked(void){
-        return _sdev->get_tx_lo_locked();
-    }
-
-    dboard_iface::sptr get_tx_dboard_iface(void){
-        return _sdev->get_tx_dboard_iface();
-    }
-
-private:
-    single_usrp::sptr _sdev;
-};
-
-/***********************************************************************
- * The Make Function
- **********************************************************************/
-simple_usrp::sptr simple_usrp::make(const device_addr_t &dev_addr){
-    uhd::print_warning(
-        "The simple USRP interface has been deprecated.\n"
-        "Please switch to the single USRP interface.\n"
-        "#include <uhd/usrp/single_usrp.hpp>\n"
-        "single_usrp::sptr sdev = single_usrp::make(args);\n"
-    );
-    return sptr(new simple_usrp_impl(dev_addr));
-}
diff --git a/host/lib/usrp/single_usrp.cpp b/host/lib/usrp/single_usrp.cpp
index bb4af44b8..a0456d1f0 100644
--- a/host/lib/usrp/single_usrp.cpp
+++ b/host/lib/usrp/single_usrp.cpp
@@ -15,6 +15,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
+#include "wrapper_utils.hpp"
 #include <uhd/usrp/single_usrp.hpp>
 #include <uhd/usrp/tune_helper.hpp>
 #include <uhd/utils/assert.hpp>
@@ -32,10 +33,7 @@
 using namespace uhd;
 using namespace uhd::usrp;
 
-static inline freq_range_t add_dsp_shift(const freq_range_t &range, wax::obj dsp){
-    double codec_rate = dsp[DSP_PROP_CODEC_RATE].as<double>();
-    return freq_range_t(range.min - codec_rate/2.0, range.max + codec_rate/2.0);
-}
+const std::string single_usrp::ALL_GAINS = "";
 
 /***********************************************************************
  * Simple USRP Implementation
@@ -46,14 +44,13 @@ public:
         _dev = device::make(addr);
     }
 
-    ~single_usrp_impl(void){
-        /* NOP */
-    }
-
     device::sptr get_device(void){
         return _dev;
     }
 
+    /*******************************************************************
+     * Mboard methods
+     ******************************************************************/
     std::string get_pp_string(void){
         std::string buff = str(boost::format(
             "Single USRP:\n"
@@ -101,9 +98,10 @@ public:
         return buff;
     }
 
-    /*******************************************************************
-     * Misc
-     ******************************************************************/
+    std::string get_mboard_name(void){
+        return _mboard()[MBOARD_PROP_NAME].as<std::string>();
+    }
+
     time_spec_t get_time_now(void){
         return _mboard()[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
     }
@@ -135,20 +133,23 @@ public:
         return _mboard()[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>();
     }
 
+    std::string get_rx_subdev_name(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>();
+    }
+
     void set_rx_rate(double rate){
         _rx_dsp()[DSP_PROP_HOST_RATE] = rate;
+        do_samp_rate_warning_message(rate, get_rx_rate(), "RX");
     }
 
     double get_rx_rate(void){
         return _rx_dsp()[DSP_PROP_HOST_RATE].as<double>();
     }
 
-    tune_result_t set_rx_freq(double target_freq, size_t chan){
-        return tune_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(), chan, target_freq);
-    }
-
-    tune_result_t set_rx_freq(double target_freq, double lo_off, size_t chan){
-        return tune_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(), chan, target_freq, lo_off);
+    tune_result_t set_rx_freq(const tune_request_t &tune_request, size_t chan){
+        tune_result_t r = tune_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(), chan, tune_request);
+        do_tune_freq_warning_message(tune_request.target_freq, get_rx_freq(chan), "RX");
+        return r;
     }
 
     double get_rx_freq(size_t chan){
@@ -159,16 +160,20 @@ public:
         return add_dsp_shift(_rx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _rx_dsp());
     }
 
-    void set_rx_gain(float gain, size_t chan){
-        return _rx_gain_group(chan)->set_value(gain);
+    void set_rx_gain(float gain, const std::string &name, size_t chan){
+        return _rx_gain_group(chan)->set_value(gain, name);
+    }
+
+    float get_rx_gain(const std::string &name, size_t chan){
+        return _rx_gain_group(chan)->get_value(name);
     }
 
-    float get_rx_gain(size_t chan){
-        return _rx_gain_group(chan)->get_value();
+    gain_range_t get_rx_gain_range(const std::string &name, size_t chan){
+        return _rx_gain_group(chan)->get_range(name);
     }
 
-    gain_range_t get_rx_gain_range(size_t chan){
-        return _rx_gain_group(chan)->get_range();
+    std::vector<std::string> get_rx_gain_names(size_t chan){
+        return _rx_gain_group(chan)->get_names();
     }
 
     void set_rx_antenna(const std::string &ant, size_t chan){
@@ -187,6 +192,14 @@ public:
         return _rx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
     }
 
+    void set_rx_bandwidth(double bandwidth, size_t chan){
+        _rx_subdev(chan)[SUBDEV_PROP_BANDWIDTH] = bandwidth;
+    }
+
+    double get_rx_bandwidth(size_t chan){
+        return _rx_subdev(chan)[SUBDEV_PROP_BANDWIDTH].as<double>();
+    }
+
     float read_rssi(size_t chan){
         return _rx_subdev(chan)[SUBDEV_PROP_RSSI].as<float>();
     }
@@ -206,20 +219,23 @@ public:
         return _mboard()[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>();
     }
 
+    std::string get_tx_subdev_name(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>();
+    }
+
     void set_tx_rate(double rate){
         _tx_dsp()[DSP_PROP_HOST_RATE] = rate;
+        do_samp_rate_warning_message(rate, get_tx_rate(), "TX");
     }
 
     double get_tx_rate(void){
         return _tx_dsp()[DSP_PROP_HOST_RATE].as<double>();
     }
 
-    tune_result_t set_tx_freq(double target_freq, size_t chan){
-        return tune_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(), chan, target_freq);
-    }
-
-    tune_result_t set_tx_freq(double target_freq, double lo_off, size_t chan){
-        return tune_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(), chan, target_freq, lo_off);
+    tune_result_t set_tx_freq(const tune_request_t &tune_request, size_t chan){
+        tune_result_t r = tune_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(), chan, tune_request);
+        do_tune_freq_warning_message(tune_request.target_freq, get_tx_freq(chan), "TX");
+        return r;
     }
 
     double get_tx_freq(size_t chan){
@@ -230,16 +246,20 @@ public:
         return add_dsp_shift(_tx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _tx_dsp());
     }
 
-    void set_tx_gain(float gain, size_t chan){
-        return _tx_gain_group(chan)->set_value(gain);
+    void set_tx_gain(float gain, const std::string &name, size_t chan){
+        return _tx_gain_group(chan)->set_value(gain, name);
+    }
+
+    float get_tx_gain(const std::string &name, size_t chan){
+        return _tx_gain_group(chan)->get_value(name);
     }
 
-    float get_tx_gain(size_t chan){
-        return _tx_gain_group(chan)->get_value();
+    gain_range_t get_tx_gain_range(const std::string &name, size_t chan){
+        return _tx_gain_group(chan)->get_range(name);
     }
 
-    gain_range_t get_tx_gain_range(size_t chan){
-        return _tx_gain_group(chan)->get_range();
+    std::vector<std::string> get_tx_gain_names(size_t chan){
+        return _tx_gain_group(chan)->get_names();
     }
 
     void set_tx_antenna(const std::string &ant, size_t chan){
@@ -258,6 +278,14 @@ public:
         return _tx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
     }
 
+    void set_tx_bandwidth(double bandwidth, size_t chan){
+        _tx_subdev(chan)[SUBDEV_PROP_BANDWIDTH] = bandwidth;
+    }
+
+    double get_tx_bandwidth(size_t chan){
+        return _tx_subdev(chan)[SUBDEV_PROP_BANDWIDTH].as<double>();
+    }
+
     dboard_iface::sptr get_tx_dboard_iface(size_t chan){
         return _tx_dboard(chan)[DBOARD_PROP_DBOARD_IFACE].as<dboard_iface::sptr>();
     }
diff --git a/host/lib/usrp/subdev_spec.cpp b/host/lib/usrp/subdev_spec.cpp
index 7a3e72867..95d2cbb12 100644
--- a/host/lib/usrp/subdev_spec.cpp
+++ b/host/lib/usrp/subdev_spec.cpp
@@ -34,6 +34,10 @@ subdev_spec_pair_t::subdev_spec_pair_t(
     /* NOP */
 }
 
+bool usrp::operator==(const subdev_spec_pair_t &lhs, const subdev_spec_pair_t &rhs){
+    return (lhs.db_name == rhs.db_name) and (lhs.sd_name == rhs.sd_name);
+}
+
 subdev_spec_t::subdev_spec_t(const std::string &markup){
     BOOST_FOREACH(const std::string &pair, std::split_string(markup)){
         if (pair == "") continue;
diff --git a/host/lib/usrp/tune_helper.cpp b/host/lib/usrp/tune_helper.cpp
index 7633c67f2..fa40a8a26 100644
--- a/host/lib/usrp/tune_helper.cpp
+++ b/host/lib/usrp/tune_helper.cpp
@@ -19,6 +19,7 @@
 #include <uhd/usrp/subdev_props.hpp>
 #include <uhd/usrp/dsp_props.hpp>
 #include <uhd/usrp/dboard_iface.hpp> //unit_t
+#include <uhd/utils/algorithm.hpp>
 #include <boost/math/special_functions/sign.hpp>
 #include <cmath>
 
@@ -28,55 +29,99 @@ using namespace uhd::usrp;
 /***********************************************************************
  * Tune Helper Functions
  **********************************************************************/
-static tune_result_t tune_xx_subdev_and_dxc(
+static tune_result_t tune_xx_subdev_and_dsp(
     dboard_iface::unit_t unit,
-    wax::obj subdev, wax::obj dxc, size_t chan,
-    double target_freq, double lo_offset
+    wax::obj subdev, wax::obj dsp, size_t chan,
+    const tune_request_t &tune_request
 ){
     wax::obj subdev_freq_proxy = subdev[SUBDEV_PROP_FREQ];
-    std::string freq_name = dxc[DSP_PROP_FREQ_SHIFT_NAMES].as<prop_names_t>().at(chan);
-    wax::obj dxc_freq_proxy = dxc[named_prop_t(DSP_PROP_FREQ_SHIFT, freq_name)];
-    double dxc_sample_rate = dxc[DSP_PROP_CODEC_RATE].as<double>();
+    std::string freq_name = dsp[DSP_PROP_FREQ_SHIFT_NAMES].as<prop_names_t>().at(chan);
+    wax::obj dsp_freq_proxy = dsp[named_prop_t(DSP_PROP_FREQ_SHIFT, freq_name)];
+    double dsp_sample_rate = dsp[DSP_PROP_CODEC_RATE].as<double>();
 
-    // Ask the d'board to tune as closely as it can to target_freq+lo_offset
-    double target_inter_freq = target_freq + lo_offset;
-    subdev_freq_proxy = target_inter_freq;
-    double actual_inter_freq = subdev_freq_proxy.as<double>();
-
-    //perform the correction correction for dxc rates outside of nyquist
-    double delta_freq = std::fmod(target_freq - actual_inter_freq, dxc_sample_rate);
-    bool outside_of_nyquist = std::abs(delta_freq) > dxc_sample_rate/2.0;
-    double target_dxc_freq = (outside_of_nyquist)?
-        boost::math::sign(delta_freq)*dxc_sample_rate - delta_freq : -delta_freq;
+    //------------------------------------------------------------------
+    //-- calculate the LO offset, only used with automatic policy
+    //------------------------------------------------------------------
+    double lo_offset = 0.0;
+    if (subdev[SUBDEV_PROP_USE_LO_OFFSET].as<bool>()){
+        //If the local oscillator will be in the passband, use an offset.
+        //But constrain the LO offset by the width of the filter bandwidth.
+        double rate = dsp[DSP_PROP_HOST_RATE].as<double>();
+        double bw = subdev[SUBDEV_PROP_BANDWIDTH].as<double>();
+        if (bw > rate) lo_offset = std::min((bw - rate)/2, rate/2);
+    }
 
-    //invert the sign on the dxc freq given the following conditions
-    if (unit == dboard_iface::UNIT_TX) target_dxc_freq *= -1.0;
+    //------------------------------------------------------------------
+    //-- set the intermediate frequency depending upon the IF policy
+    //------------------------------------------------------------------
+    double target_inter_freq = 0.0;
+    switch (tune_request.inter_freq_policy){
+    case tune_request_t::POLICY_AUTO:
+        target_inter_freq = tune_request.target_freq + lo_offset;
+        subdev_freq_proxy = target_inter_freq;
+        break;
+
+    case tune_request_t::POLICY_MANUAL:
+        target_inter_freq = tune_request.inter_freq;
+        subdev_freq_proxy = target_inter_freq;
+        break;
+
+    case tune_request_t::POLICY_NONE: break; //does not set
+    }
+    double actual_inter_freq = subdev_freq_proxy.as<double>();
 
-    dxc_freq_proxy = target_dxc_freq;
-    double actual_dxc_freq = dxc_freq_proxy.as<double>();
+    //------------------------------------------------------------------
+    //-- calculate the dsp freq, only used with automatic policy
+    //------------------------------------------------------------------
+    double delta_freq = std::fmod(tune_request.target_freq - actual_inter_freq, dsp_sample_rate);
+    bool outside_of_nyquist = std::abs(delta_freq) > dsp_sample_rate/2.0;
+    double target_dsp_freq = (outside_of_nyquist)?
+        boost::math::sign(delta_freq)*dsp_sample_rate - delta_freq : -delta_freq;
+
+    //invert the sign on the dsp freq given the following conditions
+    if (unit == dboard_iface::UNIT_TX) target_dsp_freq *= -1.0;
+
+    //------------------------------------------------------------------
+    //-- set the dsp frequency depending upon the dsp frequency policy
+    //------------------------------------------------------------------
+    switch (tune_request.dsp_freq_policy){
+    case tune_request_t::POLICY_AUTO:
+        dsp_freq_proxy = target_dsp_freq;
+        break;
+
+    case tune_request_t::POLICY_MANUAL:
+        target_dsp_freq = tune_request.dsp_freq;
+        dsp_freq_proxy = target_dsp_freq;
+        break;
+
+    case tune_request_t::POLICY_NONE: break; //does not set
+    }
+    double actual_dsp_freq = dsp_freq_proxy.as<double>();
 
-    //load and return the tune result
+    //------------------------------------------------------------------
+    //-- load and return the tune result
+    //------------------------------------------------------------------
     tune_result_t tune_result;
     tune_result.target_inter_freq = target_inter_freq;
     tune_result.actual_inter_freq = actual_inter_freq;
-    tune_result.target_dsp_freq = target_dxc_freq;
-    tune_result.actual_dsp_freq = actual_dxc_freq;
+    tune_result.target_dsp_freq = target_dsp_freq;
+    tune_result.actual_dsp_freq = actual_dsp_freq;
     return tune_result;
 }
 
-static double derive_freq_from_xx_subdev_and_dxc(
+static double derive_freq_from_xx_subdev_and_dsp(
     dboard_iface::unit_t unit,
-    wax::obj subdev, wax::obj dxc, size_t chan
+    wax::obj subdev, wax::obj dsp, size_t chan
 ){
     //extract actual dsp and IF frequencies
     double actual_inter_freq = subdev[SUBDEV_PROP_FREQ].as<double>();
-    std::string freq_name = dxc[DSP_PROP_FREQ_SHIFT_NAMES].as<prop_names_t>().at(chan);
-    double actual_dxc_freq = dxc[named_prop_t(DSP_PROP_FREQ_SHIFT, freq_name)].as<double>();
+    std::string freq_name = dsp[DSP_PROP_FREQ_SHIFT_NAMES].as<prop_names_t>().at(chan);
+    double actual_dsp_freq = dsp[named_prop_t(DSP_PROP_FREQ_SHIFT, freq_name)].as<double>();
 
-    //invert the sign on the dxc freq given the following conditions
-    if (unit == dboard_iface::UNIT_TX) actual_dxc_freq *= -1.0;
+    //invert the sign on the dsp freq given the following conditions
+    if (unit == dboard_iface::UNIT_TX) actual_dsp_freq *= -1.0;
 
-    return actual_inter_freq - actual_dxc_freq;
+    return actual_inter_freq - actual_dsp_freq;
 }
 
 /***********************************************************************
@@ -84,27 +129,15 @@ static double derive_freq_from_xx_subdev_and_dxc(
  **********************************************************************/
 tune_result_t usrp::tune_rx_subdev_and_dsp(
     wax::obj subdev, wax::obj ddc, size_t chan,
-    double target_freq, double lo_offset
-){
-    return tune_xx_subdev_and_dxc(dboard_iface::UNIT_RX, subdev, ddc, chan, target_freq, lo_offset);
-}
-
-tune_result_t usrp::tune_rx_subdev_and_dsp(
-    wax::obj subdev, wax::obj ddc,
-    size_t chan, double target_freq
+    const tune_request_t &tune_request
 ){
-    double lo_offset = 0.0;
-    //if the local oscillator will be in the passband, use an offset
-    if (subdev[SUBDEV_PROP_USE_LO_OFFSET].as<bool>()){
-        lo_offset = 2.0*ddc[DSP_PROP_HOST_RATE].as<double>();
-    }
-    return tune_rx_subdev_and_dsp(subdev, ddc, chan, target_freq, lo_offset);
+    return tune_xx_subdev_and_dsp(dboard_iface::UNIT_RX, subdev, ddc, chan, tune_request);
 }
 
 double usrp::derive_freq_from_rx_subdev_and_dsp(
     wax::obj subdev, wax::obj ddc, size_t chan
 ){
-    return derive_freq_from_xx_subdev_and_dxc(dboard_iface::UNIT_RX, subdev, ddc, chan);
+    return derive_freq_from_xx_subdev_and_dsp(dboard_iface::UNIT_RX, subdev, ddc, chan);
 }
 
 /***********************************************************************
@@ -112,25 +145,13 @@ double usrp::derive_freq_from_rx_subdev_and_dsp(
  **********************************************************************/
 tune_result_t usrp::tune_tx_subdev_and_dsp(
     wax::obj subdev, wax::obj duc, size_t chan,
-    double target_freq, double lo_offset
+    const tune_request_t &tune_request
 ){
-    return tune_xx_subdev_and_dxc(dboard_iface::UNIT_TX, subdev, duc, chan, target_freq, lo_offset);
-}
-
-tune_result_t usrp::tune_tx_subdev_and_dsp(
-    wax::obj subdev, wax::obj duc,
-    size_t chan, double target_freq
-){
-    double lo_offset = 0.0;
-    //if the local oscillator will be in the passband, use an offset
-    if (subdev[SUBDEV_PROP_USE_LO_OFFSET].as<bool>()){
-        lo_offset = 2.0*duc[DSP_PROP_HOST_RATE].as<double>();
-    }
-    return tune_tx_subdev_and_dsp(subdev, duc, chan, target_freq, lo_offset);
+    return tune_xx_subdev_and_dsp(dboard_iface::UNIT_TX, subdev, duc, chan, tune_request);
 }
 
 double usrp::derive_freq_from_tx_subdev_and_dsp(
     wax::obj subdev, wax::obj duc, size_t chan
 ){
-    return derive_freq_from_xx_subdev_and_dxc(dboard_iface::UNIT_TX, subdev, duc, chan);
+    return derive_freq_from_xx_subdev_and_dsp(dboard_iface::UNIT_TX, subdev, duc, chan);
 }
diff --git a/host/lib/usrp/usrp1/codec_ctrl.cpp b/host/lib/usrp/usrp1/codec_ctrl.cpp
index ad16f6b3a..4aa730573 100644
--- a/host/lib/usrp/usrp1/codec_ctrl.cpp
+++ b/host/lib/usrp/usrp1/codec_ctrl.cpp
@@ -61,6 +61,9 @@ public:
     float get_tx_pga_gain(void);
     void set_rx_pga_gain(float, char);
     float get_rx_pga_gain(char);
+    
+    //rx adc buffer control
+    void bypass_adc_buffers(bool bypass);
 
 private:
     usrp1_iface::sptr _iface;
@@ -419,6 +422,17 @@ void usrp1_codec_ctrl_impl::set_duc_freq(double freq)
 }
 
 /***********************************************************************
+ * Codec Control ADC buffer bypass
+ * Disable this for AC-coupled daughterboards (TVRX)
+ * By default it is initialized TRUE.
+ **********************************************************************/
+void usrp1_codec_ctrl_impl::bypass_adc_buffers(bool bypass) {
+    _ad9862_regs.byp_buffer_a = bypass;
+    _ad9862_regs.byp_buffer_b = bypass;
+    this->send_reg(2);
+}
+
+/***********************************************************************
  * Codec Control Make
  **********************************************************************/
 usrp1_codec_ctrl::sptr usrp1_codec_ctrl::make(usrp1_iface::sptr iface,
diff --git a/host/lib/usrp/usrp1/codec_ctrl.hpp b/host/lib/usrp/usrp1/codec_ctrl.hpp
index 259d10ef4..e2e8a010d 100644
--- a/host/lib/usrp/usrp1/codec_ctrl.hpp
+++ b/host/lib/usrp/usrp1/codec_ctrl.hpp
@@ -92,6 +92,9 @@ public:
 
     //! Set the TX modulator frequency
     virtual void set_duc_freq(double freq) = 0;
+    
+    //! Enable or disable ADC buffer bypass
+    virtual void bypass_adc_buffers(bool bypass) = 0;
 };
 
 #endif /* INCLUDED_USRP1_CODEC_CTRL_HPP */
diff --git a/host/lib/usrp/usrp1/codec_impl.cpp b/host/lib/usrp/usrp1/codec_impl.cpp
index 1756c1ed4..db53be53e 100644
--- a/host/lib/usrp/usrp1/codec_impl.cpp
+++ b/host/lib/usrp/usrp1/codec_impl.cpp
@@ -45,7 +45,7 @@ void usrp1_impl::codec_init(void)
 /***********************************************************************
  * RX Codec Properties
  **********************************************************************/
-static const std::string ad9862_pga_gain_name = "ad9862 pga";
+static const std::string adc_pga_gain_name = "PGA";
 
 void usrp1_impl::rx_codec_get(const wax::obj &key_, wax::obj &val, dboard_slot_t dboard_slot)
 {
@@ -62,21 +62,21 @@ void usrp1_impl::rx_codec_get(const wax::obj &key_, wax::obj &val, dboard_slot_t
         return;
 
     case CODEC_PROP_GAIN_NAMES:
-        val = prop_names_t(1, ad9862_pga_gain_name);
+        val = prop_names_t(1, adc_pga_gain_name);
         return;
 
     case CODEC_PROP_GAIN_RANGE:
-        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        UHD_ASSERT_THROW(key.name == adc_pga_gain_name);
         val = usrp1_codec_ctrl::rx_pga_gain_range;
         return;
 
     case CODEC_PROP_GAIN_I:
-        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        UHD_ASSERT_THROW(key.name == adc_pga_gain_name);
         val = _codec_ctrls[dboard_slot]->get_rx_pga_gain('A');
         return;
 
     case CODEC_PROP_GAIN_Q:
-        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        UHD_ASSERT_THROW(key.name == adc_pga_gain_name);
         val = _codec_ctrls[dboard_slot]->get_rx_pga_gain('B');
         return;
 
@@ -91,12 +91,12 @@ void usrp1_impl::rx_codec_set(const wax::obj &key_, const wax::obj &val, dboard_
     //handle the set request conditioned on the key
     switch(key.as<codec_prop_t>()) {
     case CODEC_PROP_GAIN_I:
-        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        UHD_ASSERT_THROW(key.name == adc_pga_gain_name);
         _codec_ctrls[dboard_slot]->set_rx_pga_gain(val.as<float>(), 'A');
         return;
 
     case CODEC_PROP_GAIN_Q:
-        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        UHD_ASSERT_THROW(key.name == adc_pga_gain_name);
         _codec_ctrls[dboard_slot]->set_rx_pga_gain(val.as<float>(), 'B');
         return;
 
@@ -107,6 +107,8 @@ void usrp1_impl::rx_codec_set(const wax::obj &key_, const wax::obj &val, dboard_
 /***********************************************************************
  * TX Codec Properties
  **********************************************************************/
+static const std::string dac_pga_gain_name = "PGA";
+
 void usrp1_impl::tx_codec_get(const wax::obj &key_, wax::obj &val, dboard_slot_t dboard_slot)
 {
     named_prop_t key = named_prop_t::extract(key_);
@@ -122,17 +124,17 @@ void usrp1_impl::tx_codec_get(const wax::obj &key_, wax::obj &val, dboard_slot_t
         return;
 
     case CODEC_PROP_GAIN_NAMES:
-        val = prop_names_t(1, ad9862_pga_gain_name);
+        val = prop_names_t(1, dac_pga_gain_name);
         return;
 
     case CODEC_PROP_GAIN_RANGE:
-        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        UHD_ASSERT_THROW(key.name == dac_pga_gain_name);
         val = usrp1_codec_ctrl::tx_pga_gain_range;
         return;
 
     case CODEC_PROP_GAIN_I: //only one gain for I and Q
     case CODEC_PROP_GAIN_Q:
-        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        UHD_ASSERT_THROW(key.name == dac_pga_gain_name);
         val = _codec_ctrls[dboard_slot]->get_tx_pga_gain();
         return;
 
@@ -148,7 +150,7 @@ void usrp1_impl::tx_codec_set(const wax::obj &key_, const wax::obj &val, dboard_
     switch(key.as<codec_prop_t>()){
     case CODEC_PROP_GAIN_I: //only one gain for I and Q
     case CODEC_PROP_GAIN_Q:
-        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        UHD_ASSERT_THROW(key.name == dac_pga_gain_name);
         _codec_ctrls[dboard_slot]->set_tx_pga_gain(val.as<float>());
         return;
 
diff --git a/host/lib/usrp/usrp1/dboard_iface.cpp b/host/lib/usrp/usrp1/dboard_iface.cpp
index 4791b55ce..1ac15a46a 100644
--- a/host/lib/usrp/usrp1/dboard_iface.cpp
+++ b/host/lib/usrp/usrp1/dboard_iface.cpp
@@ -32,6 +32,8 @@ using namespace uhd;
 using namespace uhd::usrp;
 using namespace boost::assign;
 
+static const dboard_id_t tvrx_id(0x0040);
+
 class usrp1_dboard_iface : public dboard_iface {
 public:
 
@@ -51,6 +53,10 @@ public:
         //init the clock rate shadows
         this->set_clock_rate(UNIT_RX, this->get_clock_rates(UNIT_RX).front());
         this->set_clock_rate(UNIT_TX, this->get_clock_rates(UNIT_TX).front());
+        
+        //yes this is evil but it's necessary for TVRX to work on USRP1
+        if(_rx_dboard_id == tvrx_id) _codec->bypass_adc_buffers(false);
+        //else _codec->bypass_adc_buffers(false); //don't think this is necessary
     }
 
     ~usrp1_dboard_iface()
@@ -93,6 +99,7 @@ public:
     std::vector<double> get_clock_rates(unit_t);
     double get_clock_rate(unit_t);
     void set_clock_enabled(unit_t, bool);
+    double get_codec_rate(unit_t);
 
 private:
     usrp1_iface::sptr _iface;
@@ -170,6 +177,10 @@ void usrp1_dboard_iface::set_clock_enabled(unit_t, bool)
     //TODO we can only enable for special case anyway...
 }
 
+double usrp1_dboard_iface::get_codec_rate(unit_t){
+    return _clock->get_master_clock_freq();
+}
+
 /***********************************************************************
  * GPIO
  **********************************************************************/
diff --git a/host/lib/usrp/usrp1/dboard_impl.cpp b/host/lib/usrp/usrp1/dboard_impl.cpp
index 3a8480e1b..2a2762a82 100644
--- a/host/lib/usrp/usrp1/dboard_impl.cpp
+++ b/host/lib/usrp/usrp1/dboard_impl.cpp
@@ -124,6 +124,7 @@ void usrp1_impl::rx_dboard_get(const wax::obj &key_, wax::obj &val, dboard_slot_
 
     case DBOARD_PROP_GAIN_GROUP:
         val = make_gain_group(
+            _rx_db_eeproms[dboard_slot].id,
             _dboard_managers[dboard_slot]->get_rx_subdev(key.name),
             _rx_codec_proxies[dboard_slot]->get_link(),
             GAIN_GROUP_POLICY_RX
@@ -188,6 +189,7 @@ void usrp1_impl::tx_dboard_get(const wax::obj &key_, wax::obj &val, dboard_slot_
 
     case DBOARD_PROP_GAIN_GROUP:
         val = make_gain_group(
+            _tx_db_eeproms[dboard_slot].id,
             _dboard_managers[dboard_slot]->get_tx_subdev(key.name),
             _tx_codec_proxies[dboard_slot]->get_link(),
             GAIN_GROUP_POLICY_TX
diff --git a/host/lib/usrp/usrp1/io_impl.cpp b/host/lib/usrp/usrp1/io_impl.cpp
index 73974f2d6..6728d9b15 100644
--- a/host/lib/usrp/usrp1/io_impl.cpp
+++ b/host/lib/usrp/usrp1/io_impl.cpp
@@ -33,33 +33,26 @@ using namespace uhd::usrp;
 using namespace uhd::transport;
 namespace asio = boost::asio;
 
+static const size_t alignment_padding = 512;
+
 /***********************************************************************
- * Pseudo send buffer implementation
+ * Helper struct to associate an offset with a buffer
  **********************************************************************/
-class pseudo_managed_send_buffer : public managed_send_buffer{
+class offset_send_buffer{
 public:
+    typedef boost::shared_ptr<offset_send_buffer> sptr;
 
-    pseudo_managed_send_buffer(
-        const boost::asio::mutable_buffer &buff,
-        const boost::function<ssize_t(size_t)> &commit
-    ):
-        _buff(buff),
-        _commit(commit)
-    {
-        /* NOP */
+    static sptr make(managed_send_buffer::sptr buff, size_t offset = 0){
+        return sptr(new offset_send_buffer(buff, offset));
     }
 
-    ssize_t commit(size_t num_bytes){
-        return _commit(num_bytes);
-    }
+    //member variables
+    managed_send_buffer::sptr buff;
+    size_t offset; /* in bytes */
 
 private:
-    const boost::asio::mutable_buffer &get(void) const{
-        return _buff;
-    }
-
-    const boost::asio::mutable_buffer      _buff;
-    const boost::function<ssize_t(size_t)> _commit;
+    offset_send_buffer(managed_send_buffer::sptr buff, size_t offset):
+        buff(buff), offset(offset){/* NOP */}
 };
 
 /***********************************************************************
@@ -70,8 +63,8 @@ struct usrp1_impl::io_impl{
         data_transport(data_transport),
         underflow_poll_samp_count(0),
         overflow_poll_samp_count(0),
-        send_buff(data_transport->get_send_buff()),
-        num_bytes_committed(0)
+        curr_buff_committed(true),
+        curr_buff(offset_send_buffer::make(data_transport->get_send_buff()))
     {
         /* NOP */
     }
@@ -91,100 +84,91 @@ struct usrp1_impl::io_impl{
     size_t overflow_poll_samp_count;
 
     //wrapper around the actual send buffer interface
-    //all of this to ensure only full buffers are committed
-    managed_send_buffer::sptr send_buff;
-    size_t num_bytes_committed;
-    boost::uint8_t pseudo_buff[BYTES_PER_PACKET];
-    ssize_t phony_commit_pseudo_buff(size_t num_bytes);
-    ssize_t phony_commit_send_buff(size_t num_bytes);
-    ssize_t commit_send_buff(void);
+    //all of this to ensure only aligned lengths are committed
+    //NOTE: you must commit before getting a new buffer
+    //since the vrt packet handler obeys this, we are ok
+    bool curr_buff_committed;
+    offset_send_buffer::sptr curr_buff;
+    void commit_send_buff(offset_send_buffer::sptr, offset_send_buffer::sptr, size_t);
     void flush_send_buff(void);
-    bool get_send_buffs(vrt_packet_handler::managed_send_buffs_t &);
-
-    //helpers to get at the send buffer + offset
-    inline void *get_send_mem_ptr(void){
-        return send_buff->cast<boost::uint8_t *>() + num_bytes_committed;
-    }
-    inline size_t get_send_mem_size(void){
-        return send_buff->size() - num_bytes_committed;
-    }
+    bool get_send_buffs(vrt_packet_handler::managed_send_buffs_t &, double);
 };
 
 /*!
- * Accept a commit of num bytes to the pseudo buffer.
- * Memcpy the entire contents of pseudo buffer into send buffers.
- *
- * Under most conditions:
- *   The first loop iteration will fill the remainder of the send buffer.
- *   The second loop iteration will empty the pseudo buffer remainder.
+ * Perform an actual commit on the send buffer:
+ * Copy the remainder of alignment to the next buffer.
+ * Commit the current buffer at multiples of alignment.
  */
-ssize_t usrp1_impl::io_impl::phony_commit_pseudo_buff(size_t num_bytes){
-    size_t bytes_to_copy = num_bytes, bytes_copied = 0;
-    while(bytes_to_copy){
-        size_t bytes_copied_here = std::min(bytes_to_copy, get_send_mem_size());
-        std::memcpy(get_send_mem_ptr(), pseudo_buff + bytes_copied, bytes_copied_here);
-        ssize_t ret = phony_commit_send_buff(bytes_copied_here);
-        if (ret < 0) return ret;
-        bytes_to_copy -= ret;
-        bytes_copied += ret;
-    }
-    return bytes_copied;
-}
+void usrp1_impl::io_impl::commit_send_buff(
+    offset_send_buffer::sptr curr,
+    offset_send_buffer::sptr next,
+    size_t num_bytes
+){
+    //total number of bytes now in the current buffer
+    size_t bytes_in_curr_buffer = curr->offset + num_bytes;
+
+    //calculate how many to commit and remainder
+    size_t num_bytes_remaining = bytes_in_curr_buffer % alignment_padding;
+    size_t num_bytes_to_commit = bytes_in_curr_buffer - num_bytes_remaining;
+
+    //copy the remainder into the next buffer
+    std::memcpy(
+        next->buff->cast<char *>() + next->offset,
+        curr->buff->cast<char *>() + num_bytes_to_commit,
+        num_bytes_remaining
+    );
 
-/*!
- * Accept a commit of num bytes to the send buffer.
- * Conditionally commit the send buffer if full.
- */
-ssize_t usrp1_impl::io_impl::phony_commit_send_buff(size_t num_bytes){
-    num_bytes_committed += num_bytes;
-    if (num_bytes_committed != send_buff->size()) return num_bytes;
-    ssize_t ret = commit_send_buff();
-    return (ret < 0)? ret : num_bytes;
+    //update the offset into the next buffer
+    next->offset += num_bytes_remaining;
+
+    //commit the current buffer
+    curr->buff->commit(num_bytes_to_commit);
+    curr_buff_committed = true;
 }
 
 /*!
- * Flush the send buffer:
- * Zero-pad the send buffer to the nearest 512 byte boundary and commit.
+ * Flush the current buffer by padding out to alignment and committing.
  */
 void usrp1_impl::io_impl::flush_send_buff(void){
-    size_t bytes_to_pad = (-1*num_bytes_committed)%512;
-    std::memset(get_send_mem_ptr(), 0, bytes_to_pad);
-    num_bytes_committed += bytes_to_pad;
-    commit_send_buff();
+    //calculate the number of bytes to alignment
+    size_t bytes_to_pad = (-1*curr_buff->offset)%alignment_padding;
+
+    //get the buffer, clear, and commit (really current buffer)
+    vrt_packet_handler::managed_send_buffs_t buffs(1);
+    if (this->get_send_buffs(buffs, 0.1)){
+        std::memset(buffs[0]->cast<void *>(), 0, bytes_to_pad);
+        buffs[0]->commit(bytes_to_pad);
+    }
 }
 
 /*!
- * Perform an actual commit on the send buffer:
- * Commit the contents of the send buffer and request a new buffer.
+ * Get a managed send buffer with the alignment padding:
+ * Always grab the next send buffer so we can timeout here.
  */
-ssize_t usrp1_impl::io_impl::commit_send_buff(void){
-    ssize_t ret = send_buff->commit(num_bytes_committed);
-    send_buff = data_transport->get_send_buff();
-    num_bytes_committed = 0;
-    return ret;
-}
-
 bool usrp1_impl::io_impl::get_send_buffs(
-    vrt_packet_handler::managed_send_buffs_t &buffs
+    vrt_packet_handler::managed_send_buffs_t &buffs, double timeout
 ){
-    UHD_ASSERT_THROW(buffs.size() == 1);
+    UHD_ASSERT_THROW(curr_buff_committed and buffs.size() == 1);
+
+    //try to get a new managed buffer with timeout
+    offset_send_buffer::sptr next_buff(offset_send_buffer::make(data_transport->get_send_buff(timeout)));
+    if (not next_buff->buff.get()) return false; /* propagate timeout here */
+
+    //calculate the buffer pointer and size given the offset
+    //references to the buffers are held in the bound function
+    buffs[0] = managed_send_buffer::make_safe(
+        boost::asio::buffer(
+            curr_buff->buff->cast<char *>() + curr_buff->offset,
+            curr_buff->buff->size()         - curr_buff->offset
+        ),
+        boost::bind(&usrp1_impl::io_impl::commit_send_buff, this, curr_buff, next_buff, _1)
+    );
 
-    //not enough bytes free -> use the pseudo buffer
-    if (get_send_mem_size() < BYTES_PER_PACKET){
-        buffs[0] = managed_send_buffer::sptr(new pseudo_managed_send_buffer(
-            boost::asio::buffer(pseudo_buff),
-            boost::bind(&usrp1_impl::io_impl::phony_commit_pseudo_buff, this, _1)
-        ));
-    }
-    //otherwise use the send buffer offset by the bytes written
-    else{
-        buffs[0] = managed_send_buffer::sptr(new pseudo_managed_send_buffer(
-            boost::asio::buffer(get_send_mem_ptr(), get_send_mem_size()),
-            boost::bind(&usrp1_impl::io_impl::phony_commit_send_buff, this, _1)
-        ));
-    }
+    //store the next buffer for the next call
+    curr_buff = next_buff;
+    curr_buff_committed = false;
 
-    return buffs[0].get() != NULL;
+    return true;
 }
 
 /***********************************************************************
@@ -213,10 +197,17 @@ static void usrp1_bs_vrt_packer(
     if_packet_info.num_packet_words32 = if_packet_info.num_payload_words32;
 }
 
+size_t usrp1_impl::get_max_send_samps_per_packet(void) const {
+    return (_data_transport->get_send_frame_size() - alignment_padding)
+        / _tx_otw_type.get_sample_size()
+        / _tx_subdev_spec.size()
+    ;
+}
+
 size_t usrp1_impl::send(
     const std::vector<const void *> &buffs, size_t num_samps,
     const tx_metadata_t &metadata, const io_type_t &io_type,
-    send_mode_t send_mode
+    send_mode_t send_mode, double timeout
 ){
     size_t num_samps_sent = vrt_packet_handler::send(
         _io_impl->packet_handler_send_state,       //last state of the send handler
@@ -225,7 +216,7 @@ size_t usrp1_impl::send(
         io_type, _tx_otw_type,                     //input and output types to convert
         _clock_ctrl->get_master_clock_freq(),      //master clock tick rate
         &usrp1_bs_vrt_packer,
-        boost::bind(&usrp1_impl::io_impl::get_send_buffs, _io_impl.get(), _1),
+        boost::bind(&usrp1_impl::io_impl::get_send_buffs, _io_impl.get(), _1, timeout),
         get_max_send_samps_per_packet(),
         0,                                         //vrt header offset
         _tx_subdev_spec.size()                     //num channels
@@ -272,18 +263,25 @@ static void usrp1_bs_vrt_unpacker(
 }
 
 static bool get_recv_buffs(
-    zero_copy_if::sptr zc_if,
+    zero_copy_if::sptr zc_if, double timeout,
     vrt_packet_handler::managed_recv_buffs_t &buffs
 ){
     UHD_ASSERT_THROW(buffs.size() == 1);
-    buffs[0] = zc_if->get_recv_buff();
+    buffs[0] = zc_if->get_recv_buff(timeout);
     return buffs[0].get() != NULL;
 }
 
+size_t usrp1_impl::get_max_recv_samps_per_packet(void) const {
+    return _data_transport->get_recv_frame_size()
+        / _rx_otw_type.get_sample_size()
+        / _rx_subdev_spec.size()
+    ;
+}
+
 size_t usrp1_impl::recv(
     const std::vector<void *> &buffs, size_t num_samps,
     rx_metadata_t &metadata, const io_type_t &io_type,
-    recv_mode_t recv_mode, size_t /*timeout_ms TODO*/
+    recv_mode_t recv_mode, double timeout
 ){
     size_t num_samps_recvd = vrt_packet_handler::recv(
         _io_impl->packet_handler_recv_state,       //last state of the recv handler
@@ -292,7 +290,7 @@ size_t usrp1_impl::recv(
         io_type, _rx_otw_type,                     //input and output types to convert
         _clock_ctrl->get_master_clock_freq(),      //master clock tick rate
         &usrp1_bs_vrt_unpacker,
-        boost::bind(&get_recv_buffs, _data_transport, _1),
+        boost::bind(&get_recv_buffs, _data_transport, timeout, _1),
         &vrt_packet_handler::handle_overflow_nop,
         0,                                         //vrt header offset
         _rx_subdev_spec.size()                     //num channels
diff --git a/host/lib/usrp/usrp1/mboard_impl.cpp b/host/lib/usrp/usrp1/mboard_impl.cpp
index fe3774eb4..669b20efa 100644
--- a/host/lib/usrp/usrp1/mboard_impl.cpp
+++ b/host/lib/usrp/usrp1/mboard_impl.cpp
@@ -98,7 +98,7 @@ static boost::uint32_t calc_rx_mux(
     //    for all quadrature sources: Z = 0
     //    for mixed sources: warning + Z = 0
     int Z = (num_quads > 0)? 0 : 1;
-    if (num_quads != 0 and num_reals != 0) uhd::print_warning(
+    if (num_quads != 0 and num_reals != 0) uhd::warning::post(
         "Mixing real and quadrature rx subdevices is not supported.\n"
         "The Q input to the real source(s) will be non-zero.\n"
     );
diff --git a/host/lib/usrp/usrp1/usrp1_ctrl.cpp b/host/lib/usrp/usrp1/usrp1_ctrl.cpp
index 1dc6e6e25..5043aed7d 100644
--- a/host/lib/usrp/usrp1/usrp1_ctrl.cpp
+++ b/host/lib/usrp/usrp1/usrp1_ctrl.cpp
@@ -38,6 +38,8 @@ enum firmware_code {
 
 #define FX2_FIRMWARE_LOAD 0xa0
 
+static const bool load_img_msg = true;
+
 /***********************************************************************
  * Helper Functions
  **********************************************************************/
@@ -178,6 +180,7 @@ public:
         unsigned char reset_n = 0;
 
         //hit the reset line
+        if (load_img_msg) std::cout << "Loading firmware image: " << filestring << "..." << std::flush;
         usrp_control_write(FX2_FIRMWARE_LOAD, 0xe600, 0,
                            &reset_y, 1);
  
@@ -206,14 +209,14 @@ public:
             }  
             //type 0x01 is end 
             else if (type == 0x01) {
+                usrp_set_firmware_hash(hash); //set hash before reset
                 usrp_control_write(FX2_FIRMWARE_LOAD, 0xe600, 0,
                                    &reset_n, 1);
-                usrp_set_firmware_hash(hash);
                 file.close();
 
                 //wait for things to settle
                 boost::this_thread::sleep(boost::posix_time::milliseconds(1000));
-
+                if (load_img_msg) std::cout << " done" << std::endl;
                 return USRP_FIRMWARE_LOAD_SUCCESS; 
             }
             //type anything else is unhandled
@@ -249,6 +252,7 @@ public:
         unsigned char buf[ep0_size];
         int ret;
 
+        if (load_img_msg) std::cout << "Loading FPGA image: " << filestring << "..." << std::flush;
         std::ifstream file;
         file.open(filename, std::ios::in | std::ios::binary);
         if (not file.good()) {
@@ -263,11 +267,12 @@ public:
             return -1;
         }
 
-        ssize_t n;
-        while ((n = file.readsome((char *)buf, sizeof(buf))) > 0) {
+        while (not file.eof()) {
+            file.read((char *)buf, sizeof(buf));
+            size_t n = file.gcount();
             ret = usrp_control_write(VRQ_FPGA_LOAD, 0, FL_XFER,
                                      buf, n);
-            if (ret != n) {
+            if (ret < 0 or size_t(ret) != n) {
                 std::cerr << "fpga load error " << ret << std::endl;
                 file.close();
                 return -1;
@@ -282,6 +287,7 @@ public:
 
         usrp_set_fpga_hash(hash);
         file.close();
+        if (load_img_msg) std::cout << " done" << std::endl;
         return 0; 
     }
 
diff --git a/host/lib/usrp/usrp1/usrp1_iface.cpp b/host/lib/usrp/usrp1/usrp1_iface.cpp
index 5fd3987d5..64ced2905 100644
--- a/host/lib/usrp/usrp1/usrp1_iface.cpp
+++ b/host/lib/usrp/usrp1/usrp1_iface.cpp
@@ -49,7 +49,7 @@ public:
      ******************************************************************/
     void poke32(boost::uint32_t addr, boost::uint32_t value)
     {
-        boost::uint32_t swapped = byteswap(value);
+        boost::uint32_t swapped = uhd::htonx(value);
 
         if (iface_debug) {
             std::cout.fill('0');
@@ -72,12 +72,6 @@ public:
             std::cerr << "USRP: failed memory write: " << ret << std::endl;
     }
 
-    void poke16(boost::uint32_t, boost::uint16_t)
-    {
-        //fpga only handles 32 bit writes
-        std::cerr << "USRP: unsupported operation: poke16()" << std::endl;
-    }
-
     boost::uint32_t peek32(boost::uint32_t addr)
     {
         boost::uint32_t value_out;
@@ -95,13 +89,7 @@ public:
         if (ret < 0)
             std::cerr << "USRP: failed memory read: " << ret << std::endl;
 
-        return byteswap(value_out);
-    }
-
-    boost::uint16_t peek16(boost::uint32_t addr)
-    {
-        boost::uint32_t val = peek32(addr);
-        return boost::uint16_t(val & 0xff);
+        return uhd::ntohx(value_out);
     }
 
     /*******************************************************************
diff --git a/host/lib/usrp/usrp1/usrp1_iface.hpp b/host/lib/usrp/usrp1/usrp1_iface.hpp
index 9a3fdd6bc..3f608584a 100644
--- a/host/lib/usrp/usrp1/usrp1_iface.hpp
+++ b/host/lib/usrp/usrp1/usrp1_iface.hpp
@@ -54,20 +54,6 @@ public:
     virtual boost::uint32_t peek32(boost::uint32_t addr) = 0;
 
     /*!
-     * Write a register (16 bits)
-     * \param addr the address
-     * \param data the 16bit data
-     */
-    virtual void poke16(boost::uint32_t addr, boost::uint16_t data) = 0;
-
-    /*!
-     * read a register (16 bits)
-     * \param addr the address
-     * \return the 16bit data
-     */
-    virtual boost::uint16_t peek16(boost::uint32_t addr) = 0;
-
-    /*!
      * Perform an spi transaction.
      * \param which_slave the slave device number
      * \param config spi config args
diff --git a/host/lib/usrp/usrp1/usrp1_impl.cpp b/host/lib/usrp/usrp1/usrp1_impl.cpp
index 627180b11..314384e72 100644
--- a/host/lib/usrp/usrp1/usrp1_impl.cpp
+++ b/host/lib/usrp/usrp1/usrp1_impl.cpp
@@ -30,6 +30,7 @@
 #include <boost/assign/list_of.hpp>
 #include <boost/filesystem.hpp>
 #include <boost/thread/thread.hpp>
+#include <boost/lexical_cast.hpp>
 #include <iostream>
 
 using namespace uhd;
@@ -63,7 +64,7 @@ static device_addrs_t usrp1_find(const device_addr_t &hint)
         );
     }
     catch(...){
-        uhd::print_warning(
+        uhd::warning::post(
             "Could not locate USRP1 firmware.\n"
             "Please install the images package.\n"
         );
@@ -74,29 +75,29 @@ static device_addrs_t usrp1_find(const device_addr_t &hint)
     boost::uint16_t vid = hint.has_key("uninit") ? FX2_VENDOR_ID : USRP1_VENDOR_ID;
     boost::uint16_t pid = hint.has_key("uninit") ? FX2_PRODUCT_ID : USRP1_PRODUCT_ID;
 
-    //see what we got on the USB bus
-    std::vector<usb_device_handle::sptr> device_list =
-        usb_device_handle::get_device_list(vid, pid);
-
-    if(device_list.size() == 0) return usrp1_addrs; //return nothing if no USRPs found
+    // Important note:
+    // The get device list calls are nested inside the for loop.
+    // This allows the usb guts to decontruct when not in use,
+    // so that re-enumeration after fw load can occur successfully.
+    // This requirement is a courtesy of libusb1.0 on windows.
 
     //find the usrps and load firmware
-    BOOST_FOREACH(usb_device_handle::sptr handle, device_list) {
-            usb_control::sptr ctrl_transport = usb_control::make(handle);
-            usrp_ctrl::sptr usrp_ctrl = usrp_ctrl::make(ctrl_transport);
-            usrp_ctrl->usrp_load_firmware(usrp1_fw_image);
+    BOOST_FOREACH(usb_device_handle::sptr handle, usb_device_handle::get_device_list(vid, pid)) {
+        usrp_ctrl::make(usb_control::make(handle))->usrp_load_firmware(usrp1_fw_image);
     }
 
     //get descriptors again with serial number, but using the initialized VID/PID now since we have firmware
     vid = USRP1_VENDOR_ID;
     pid = USRP1_PRODUCT_ID;
-    device_list = usb_device_handle::get_device_list(vid, pid);
 
-    BOOST_FOREACH(usb_device_handle::sptr handle, device_list) {
-            device_addr_t new_addr;
-            new_addr["type"] = "usrp1";
-            new_addr["serial"] = handle->get_serial();
+    BOOST_FOREACH(usb_device_handle::sptr handle, usb_device_handle::get_device_list(vid, pid)) {
+        device_addr_t new_addr;
+        new_addr["type"] = "usrp1";
+        new_addr["serial"] = handle->get_serial();
+        //this is a found usrp1 when a hint serial is not specified or it matches
+        if (not hint.has_key("serial") or hint["serial"] == new_addr["serial"]){
             usrp1_addrs.push_back(new_addr);
+        }
     }
 
     return usrp1_addrs;
@@ -105,8 +106,8 @@ static device_addrs_t usrp1_find(const device_addr_t &hint)
 /***********************************************************************
  * Make
  **********************************************************************/
-static device::sptr usrp1_make(const device_addr_t &device_addr)
-{
+static device::sptr usrp1_make(const device_addr_t &device_addr){
+
     //extract the FPGA path for the USRP1
     std::string usrp1_fpga_image = find_image_path(
         device_addr.has_key("fpga")? device_addr["fpga"] : "usrp1_fpga.rbf"
@@ -117,25 +118,26 @@ static device::sptr usrp1_make(const device_addr_t &device_addr)
     std::vector<usb_device_handle::sptr> device_list =
         usb_device_handle::get_device_list(USRP1_VENDOR_ID, USRP1_PRODUCT_ID);
 
-    //create data and control transports
-    usb_zero_copy::sptr data_transport;
-    usrp_ctrl::sptr usrp_ctrl;
-
-
-    BOOST_FOREACH(usb_device_handle::sptr handle, device_list) {
-        if (handle->get_serial() == device_addr["serial"]) {
-            usb_control::sptr ctrl_transport = usb_control::make(handle);
-            usrp_ctrl = usrp_ctrl::make(ctrl_transport);
-            usrp_ctrl->usrp_load_fpga(usrp1_fpga_image);
-
-            data_transport = usb_zero_copy::make(handle,        // identifier
-                                                 6,             // IN endpoint
-                                                 2,             // OUT endpoint
-                                                 2 * (1 << 20), // buffer size
-                                                 16384);        // transfer size
+    //locate the matching handle in the device list
+    usb_device_handle::sptr handle;
+    BOOST_FOREACH(usb_device_handle::sptr dev_handle, device_list) {
+        if (dev_handle->get_serial() == device_addr["serial"]){
+            handle = dev_handle;
             break;
         }
     }
+    UHD_ASSERT_THROW(handle.get() != NULL); //better be found
+
+    //create control objects and a data transport
+    usb_control::sptr ctrl_transport = usb_control::make(handle);
+    usrp_ctrl::sptr usrp_ctrl = usrp_ctrl::make(ctrl_transport);
+    usrp_ctrl->usrp_load_fpga(usrp1_fpga_image);
+    usb_zero_copy::sptr data_transport = usb_zero_copy::make(
+        handle,        // identifier
+        6,             // IN endpoint
+        2,             // OUT endpoint
+        device_addr    // param hints
+    );
 
     //create the usrp1 implementation guts
     return device::sptr(new usrp1_impl(data_transport, usrp_ctrl));
@@ -171,7 +173,7 @@ usrp1_impl::usrp1_impl(uhd::transport::usb_zero_copy::sptr data_transport,
     //initialize the mboard
     mboard_init();
 
-    //initialize the dboards 
+    //initialize the dboards
     dboard_init();
 
     //initialize the dsps
@@ -195,9 +197,9 @@ usrp1_impl::~usrp1_impl(void){
     /* NOP */
 }
 
-bool usrp1_impl::recv_async_msg(uhd::async_metadata_t &, size_t timeout_ms){
+bool usrp1_impl::recv_async_msg(uhd::async_metadata_t &, double timeout){
     //dummy fill-in for the recv_async_msg
-    boost::this_thread::sleep(boost::posix_time::milliseconds(timeout_ms));
+    boost::this_thread::sleep(boost::posix_time::microseconds(long(timeout*1e6)));
     return false;
 }
 
diff --git a/host/lib/usrp/usrp1/usrp1_impl.hpp b/host/lib/usrp/usrp1/usrp1_impl.hpp
index 20ae3c02a..ff4d40762 100644
--- a/host/lib/usrp/usrp1/usrp1_impl.hpp
+++ b/host/lib/usrp/usrp1/usrp1_impl.hpp
@@ -83,25 +83,18 @@ public:
                 size_t,
                 const uhd::tx_metadata_t &,
                 const uhd::io_type_t &,
-                send_mode_t);
+                send_mode_t, double);
 
     size_t recv(const std::vector<void *> &,
                 size_t, uhd::rx_metadata_t &,
                 const uhd::io_type_t &,
-                recv_mode_t,
-                size_t timeout);
+                recv_mode_t, double);
 
-    static const size_t BYTES_PER_PACKET = 512*4; //under the transfer size
+    size_t get_max_send_samps_per_packet(void) const;
 
-    size_t get_max_send_samps_per_packet(void) const {
-        return BYTES_PER_PACKET/_tx_otw_type.get_sample_size()/_tx_subdev_spec.size();
-    }
-
-    size_t get_max_recv_samps_per_packet(void) const {
-        return BYTES_PER_PACKET/_rx_otw_type.get_sample_size()/_rx_subdev_spec.size();
-    }
+    size_t get_max_recv_samps_per_packet(void) const;
 
-    bool recv_async_msg(uhd::async_metadata_t &, size_t);
+    bool recv_async_msg(uhd::async_metadata_t &, double);
 
 private:
     /*!
diff --git a/host/lib/usrp/usrp2/dboard_iface.cpp b/host/lib/usrp/usrp2/dboard_iface.cpp
index f6d2b718a..fdfbf0d17 100644
--- a/host/lib/usrp/usrp2/dboard_iface.cpp
+++ b/host/lib/usrp/usrp2/dboard_iface.cpp
@@ -61,6 +61,7 @@ public:
     double get_clock_rate(unit_t);
     std::vector<double> get_clock_rates(unit_t);
     void set_clock_enabled(unit_t, bool);
+    double get_codec_rate(unit_t);
 
     void write_spi(
         unit_t unit,
@@ -158,6 +159,9 @@ void usrp2_dboard_iface::set_clock_enabled(unit_t unit, bool enb){
     }
 }
 
+double usrp2_dboard_iface::get_codec_rate(unit_t){
+    return _clock_ctrl->get_master_clock_rate();
+}
 /***********************************************************************
  * GPIO
  **********************************************************************/
diff --git a/host/lib/usrp/usrp2/dboard_impl.cpp b/host/lib/usrp/usrp2/dboard_impl.cpp
index a462b93c2..540c9fefb 100644
--- a/host/lib/usrp/usrp2/dboard_impl.cpp
+++ b/host/lib/usrp/usrp2/dboard_impl.cpp
@@ -89,6 +89,7 @@ void usrp2_mboard_impl::rx_dboard_get(const wax::obj &key_, wax::obj &val){
 
     case DBOARD_PROP_GAIN_GROUP:
         val = make_gain_group(
+            _rx_db_eeprom.id,
             _dboard_manager->get_rx_subdev(key.name),
             _rx_codec_proxy->get_link(),
             GAIN_GROUP_POLICY_RX
@@ -145,6 +146,7 @@ void usrp2_mboard_impl::tx_dboard_get(const wax::obj &key_, wax::obj &val){
 
     case DBOARD_PROP_GAIN_GROUP:
         val = make_gain_group(
+            _tx_db_eeprom.id,
             _dboard_manager->get_tx_subdev(key.name),
             _tx_codec_proxy->get_link(),
             GAIN_GROUP_POLICY_TX
diff --git a/host/lib/usrp/usrp2/io_impl.cpp b/host/lib/usrp/usrp2/io_impl.cpp
index 91a1b2344..bbe9c273f 100644
--- a/host/lib/usrp/usrp2/io_impl.cpp
+++ b/host/lib/usrp/usrp2/io_impl.cpp
@@ -46,7 +46,7 @@ struct usrp2_impl::io_impl{
 
     io_impl(size_t num_frames, size_t width):
         packet_handler_recv_state(width),
-        recv_pirate_booty(alignment_buffer_type::make(num_frames, width)),
+        recv_pirate_booty(alignment_buffer_type::make(num_frames-3, width)),
         async_msg_fifo(bounded_buffer<async_metadata_t>::make(100/*messages deep*/))
     {
         /* NOP */
@@ -58,9 +58,9 @@ struct usrp2_impl::io_impl{
         recv_pirate_crew.join_all();
     }
 
-    bool get_recv_buffs(vrt_packet_handler::managed_recv_buffs_t &buffs, size_t timeout_ms){
+    bool get_recv_buffs(vrt_packet_handler::managed_recv_buffs_t &buffs, double timeout){
         boost::this_thread::disable_interruption di; //disable because the wait can throw
-        return recv_pirate_booty->pop_elems_with_timed_wait(buffs, boost::posix_time::milliseconds(timeout_ms));
+        return recv_pirate_booty->pop_elems_with_timed_wait(buffs, timeout);
     }
 
     //state management for the vrt packet handler code
@@ -150,7 +150,7 @@ void usrp2_impl::io_init(void){
         std::memcpy(send_buff->cast<void*>(), &data, sizeof(data));
         send_buff->commit(sizeof(data));
         //drain the recv buffers (may have junk)
-        while (data_transport->get_recv_buff().get());
+        while (data_transport->get_recv_buff().get()){};
     }
 
     //the number of recv frames is the number for the first transport
@@ -168,22 +168,16 @@ void usrp2_impl::io_init(void){
             _mboards.at(i), i
         ));
     }
-
-    std::cout << "RX samples per packet: " << get_max_recv_samps_per_packet() << std::endl;
-    std::cout << "TX samples per packet: " << get_max_send_samps_per_packet() << std::endl;
-    std::cout << "Recv pirate num frames: " << num_frames << std::endl;
 }
 
 /***********************************************************************
  * Async Data
  **********************************************************************/
 bool usrp2_impl::recv_async_msg(
-    async_metadata_t &async_metadata, size_t timeout_ms
+    async_metadata_t &async_metadata, double timeout
 ){
     boost::this_thread::disable_interruption di; //disable because the wait can throw
-    return _io_impl->async_msg_fifo->pop_with_timed_wait(
-        async_metadata, boost::posix_time::milliseconds(timeout_ms)
-    );
+    return _io_impl->async_msg_fifo->pop_with_timed_wait(async_metadata, timeout);
 }
 
 /***********************************************************************
@@ -191,28 +185,40 @@ bool usrp2_impl::recv_async_msg(
  **********************************************************************/
 static bool get_send_buffs(
     const std::vector<udp_zero_copy::sptr> &trans,
-    vrt_packet_handler::managed_send_buffs_t &buffs
+    vrt_packet_handler::managed_send_buffs_t &buffs,
+    double timeout
 ){
     UHD_ASSERT_THROW(trans.size() == buffs.size());
+    bool good = true;
     for (size_t i = 0; i < buffs.size(); i++){
-        buffs[i] = trans[i]->get_send_buff();
+        buffs[i] = trans[i]->get_send_buff(timeout);
+        good = good and (buffs[i].get() != NULL);
     }
-    return true;
+    return good;
+}
+
+size_t usrp2_impl::get_max_send_samps_per_packet(void) const{
+    static const size_t hdr_size = 0
+        + vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
+        - sizeof(vrt::if_packet_info_t().cid) //no class id ever used
+    ;
+    const size_t bpp = _data_transports.front()->get_send_frame_size() - hdr_size;
+    return bpp/_tx_otw_type.get_sample_size();
 }
 
 size_t usrp2_impl::send(
     const std::vector<const void *> &buffs, size_t num_samps,
     const tx_metadata_t &metadata, const io_type_t &io_type,
-    send_mode_t send_mode
+    send_mode_t send_mode, double timeout
 ){
     return vrt_packet_handler::send(
         _io_impl->packet_handler_send_state,       //last state of the send handler
         buffs, num_samps,                          //buffer to fill
         metadata, send_mode,                       //samples metadata
-        io_type, _io_helper.get_tx_otw_type(),     //input and output types to convert
+        io_type, _tx_otw_type,                     //input and output types to convert
         _mboards.front()->get_master_clock_freq(), //master clock tick rate
         uhd::transport::vrt::if_hdr_pack_be,
-        boost::bind(&get_send_buffs, _data_transports, _1),
+        boost::bind(&get_send_buffs, _data_transports, _1, timeout),
         get_max_send_samps_per_packet()
     );
 }
@@ -220,18 +226,28 @@ size_t usrp2_impl::send(
 /***********************************************************************
  * Receive Data
  **********************************************************************/
+size_t usrp2_impl::get_max_recv_samps_per_packet(void) const{
+    static const size_t hdr_size = 0
+        + vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
+        + sizeof(vrt::if_packet_info_t().tlr) //forced to have trailer
+        - sizeof(vrt::if_packet_info_t().cid) //no class id ever used
+    ;
+    const size_t bpp = _data_transports.front()->get_recv_frame_size() - hdr_size;
+    return bpp/_rx_otw_type.get_sample_size();
+}
+
 size_t usrp2_impl::recv(
     const std::vector<void *> &buffs, size_t num_samps,
     rx_metadata_t &metadata, const io_type_t &io_type,
-    recv_mode_t recv_mode, size_t timeout_ms
+    recv_mode_t recv_mode, double timeout
 ){
     return vrt_packet_handler::recv(
         _io_impl->packet_handler_recv_state,       //last state of the recv handler
         buffs, num_samps,                          //buffer to fill
         metadata, recv_mode,                       //samples metadata
-        io_type, _io_helper.get_rx_otw_type(),     //input and output types to convert
+        io_type, _rx_otw_type,                     //input and output types to convert
         _mboards.front()->get_master_clock_freq(), //master clock tick rate
         uhd::transport::vrt::if_hdr_unpack_be,
-        boost::bind(&usrp2_impl::io_impl::get_recv_buffs, _io_impl.get(), _1, timeout_ms)
+        boost::bind(&usrp2_impl::io_impl::get_recv_buffs, _io_impl.get(), _1, timeout)
     );
 }
diff --git a/host/lib/usrp/usrp2/mboard_impl.cpp b/host/lib/usrp/usrp2/mboard_impl.cpp
index 0b9f8ee83..a0e6adfad 100644
--- a/host/lib/usrp/usrp2/mboard_impl.cpp
+++ b/host/lib/usrp/usrp2/mboard_impl.cpp
@@ -38,10 +38,10 @@ using namespace uhd::usrp;
 usrp2_mboard_impl::usrp2_mboard_impl(
     size_t index,
     transport::udp_simple::sptr ctrl_transport,
-    const usrp2_io_helper &io_helper
+    size_t recv_frame_size
 ):
     _index(index),
-    _io_helper(io_helper)
+    _recv_frame_size(recv_frame_size)
 {
     //make a new interface for usrp2 stuff
     _iface = usrp2_iface::make(ctrl_transport);
@@ -75,7 +75,7 @@ usrp2_mboard_impl::usrp2_mboard_impl(
     this->issue_ddc_stream_cmd(stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);
 
     //init the rx control registers
-    _iface->poke32(U2_REG_RX_CTRL_NSAMPS_PER_PKT, _io_helper.get_max_recv_samps_per_packet());
+    _iface->poke32(U2_REG_RX_CTRL_NSAMPS_PER_PKT, _recv_frame_size);
     _iface->poke32(U2_REG_RX_CTRL_NCHANNELS, 1);
     _iface->poke32(U2_REG_RX_CTRL_CLEAR_OVERRUN, 1); //reset
     _iface->poke32(U2_REG_RX_CTRL_VRT_HEADER, 0
@@ -178,7 +178,7 @@ void usrp2_mboard_impl::set_time_spec(const time_spec_t &time_spec, bool now){
 
 void usrp2_mboard_impl::issue_ddc_stream_cmd(const stream_cmd_t &stream_cmd){
     _iface->poke32(U2_REG_RX_CTRL_STREAM_CMD, dsp_type1::calc_stream_cmd_word(
-        stream_cmd, _io_helper.get_max_recv_samps_per_packet()
+        stream_cmd, _recv_frame_size
     ));
     _iface->poke32(U2_REG_RX_CTRL_TIME_SECS,  boost::uint32_t(stream_cmd.time_spec.get_full_secs()));
     _iface->poke32(U2_REG_RX_CTRL_TIME_TICKS, stream_cmd.time_spec.get_tick_count(get_master_clock_freq()));
diff --git a/host/lib/usrp/usrp2/usrp2_impl.cpp b/host/lib/usrp/usrp2/usrp2_impl.cpp
index 568c87a22..a680708ad 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.cpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.cpp
@@ -124,26 +124,7 @@ static uhd::device_addrs_t usrp2_find(const device_addr_t &hint){
 /***********************************************************************
  * Make
  **********************************************************************/
-template <typename out_type, typename in_type>
-out_type lexical_cast(const in_type &in){
-    try{
-        return boost::lexical_cast<out_type>(in);
-    }catch(...){
-        throw std::runtime_error(str(boost::format(
-            "failed to cast \"%s\" to type \"%s\""
-        ) % boost::lexical_cast<std::string>(in) % typeid(out_type).name()));
-    }
-}
-
 static device::sptr usrp2_make(const device_addr_t &device_addr){
-    //extract the receive and send buffer sizes
-    size_t recv_buff_size = 0, send_buff_size= 0 ;
-    if (device_addr.has_key("recv_buff_size")){
-        recv_buff_size = size_t(lexical_cast<double>(device_addr["recv_buff_size"]));
-    }
-    if (device_addr.has_key("send_buff_size")){
-        send_buff_size = size_t(lexical_cast<double>(device_addr["send_buff_size"]));
-    }
 
     //create a ctrl and data transport for each address
     std::vector<udp_simple::sptr> ctrl_transports;
@@ -154,8 +135,7 @@ static device::sptr usrp2_make(const device_addr_t &device_addr){
             addr, num2str(USRP2_UDP_CTRL_PORT)
         ));
         data_transports.push_back(udp_zero_copy::make(
-            addr, num2str(USRP2_UDP_DATA_PORT),
-            recv_buff_size, send_buff_size
+            addr, num2str(USRP2_UDP_DATA_PORT), device_addr
         ));
     }
 
@@ -178,11 +158,23 @@ usrp2_impl::usrp2_impl(
 ):
     _data_transports(data_transports)
 {
+    //setup rx otw type
+    _rx_otw_type.width = 16;
+    _rx_otw_type.shift = 0;
+    _rx_otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    //setup tx otw type
+    _tx_otw_type.width = 16;
+    _tx_otw_type.shift = 0;
+    _tx_otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    //!!!!! set the otw type here before continuing, its used below
+
     //create a new mboard handler for each control transport
     for(size_t i = 0; i < ctrl_transports.size(); i++){
-        _mboards.push_back(usrp2_mboard_impl::sptr(
-            new usrp2_mboard_impl(i, ctrl_transports[i], _io_helper)
-        ));
+        _mboards.push_back(usrp2_mboard_impl::sptr(new usrp2_mboard_impl(
+            i, ctrl_transports[i], this->get_max_recv_samps_per_packet()
+        )));
         //use an empty name when there is only one mboard
         std::string name = (ctrl_transports.size() > 1)? boost::lexical_cast<std::string>(i) : "";
         _mboard_dict[name] = _mboards.back();
diff --git a/host/lib/usrp/usrp2/usrp2_impl.hpp b/host/lib/usrp/usrp2/usrp2_impl.hpp
index 157d17057..558726a2b 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.hpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.hpp
@@ -72,54 +72,6 @@ private:
 };
 
 /*!
- * The io helper class encapculates the max packet sizes and otw types.
- * The otw types are read-only for now, this will be reimplemented
- * when it becomes possible to change the otw type in the usrp2.
- */
-class usrp2_io_helper{
-public:
-    usrp2_io_helper(void){
-        //setup rx otw type
-        _rx_otw_type.width = 16;
-        _rx_otw_type.shift = 0;
-        _rx_otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
-
-        //setup tx otw type
-        _tx_otw_type.width = 16;
-        _tx_otw_type.shift = 0;
-        _tx_otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
-    }
-
-    inline size_t get_max_send_samps_per_packet(void) const{
-        return _max_tx_bytes_per_packet/_tx_otw_type.get_sample_size();
-    }
-
-    inline size_t get_max_recv_samps_per_packet(void) const{
-        return _max_rx_bytes_per_packet/_rx_otw_type.get_sample_size();
-    }
-
-    inline const uhd::otw_type_t &get_rx_otw_type(void) const{
-        return _rx_otw_type;
-    }
-
-    inline const uhd::otw_type_t &get_tx_otw_type(void) const{
-        return _tx_otw_type;
-    }
-
-private:
-    uhd::otw_type_t _rx_otw_type, _tx_otw_type;
-    static const size_t _max_rx_bytes_per_packet = uhd::transport::udp_simple::mtu
-        - uhd::transport::vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
-        - sizeof(uhd::transport::vrt::if_packet_info_t().tlr) //forced to have trailer
-        + sizeof(uhd::transport::vrt::if_packet_info_t().cid) //no class id ever used
-    ;
-    static const size_t _max_tx_bytes_per_packet = uhd::transport::udp_simple::mtu
-        - uhd::transport::vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
-        + sizeof(uhd::transport::vrt::if_packet_info_t().cid) //no class id ever used
-    ;
-};
-
-/*!
  * USRP2 mboard implementation guts:
  * The implementation details are encapsulated here.
  * Handles properties on the mboard, dboard, dsps...
@@ -129,7 +81,11 @@ public:
     typedef boost::shared_ptr<usrp2_mboard_impl> sptr;
 
     //structors
-    usrp2_mboard_impl(size_t index, uhd::transport::udp_simple::sptr, const usrp2_io_helper &);
+    usrp2_mboard_impl(
+        size_t index,
+        uhd::transport::udp_simple::sptr,
+        size_t recv_frame_size
+    );
     ~usrp2_mboard_impl(void);
 
     inline double get_master_clock_freq(void){
@@ -139,7 +95,7 @@ public:
 private:
     size_t _index;
     int _rev_hi, _rev_lo;
-    const usrp2_io_helper &_io_helper;
+    const size_t _recv_frame_size;
 
     //properties for this mboard
     void get(const wax::obj &, wax::obj &);
@@ -228,23 +184,19 @@ public:
     ~usrp2_impl(void);
 
     //the io interface
-    size_t get_max_send_samps_per_packet(void) const{
-        return _io_helper.get_max_send_samps_per_packet();
-    }
     size_t send(
         const std::vector<const void *> &, size_t,
         const uhd::tx_metadata_t &, const uhd::io_type_t &,
-        uhd::device::send_mode_t
+        uhd::device::send_mode_t, double
     );
-    size_t get_max_recv_samps_per_packet(void) const{
-        return _io_helper.get_max_recv_samps_per_packet();
-    }
     size_t recv(
         const std::vector<void *> &, size_t,
         uhd::rx_metadata_t &, const uhd::io_type_t &,
-        uhd::device::recv_mode_t, size_t
+        uhd::device::recv_mode_t, double
     );
-    bool recv_async_msg(uhd::async_metadata_t &, size_t);
+    size_t get_max_send_samps_per_packet(void) const;
+    size_t get_max_recv_samps_per_packet(void) const;
+    bool recv_async_msg(uhd::async_metadata_t &, double);
 
 private:
     //device properties interface
@@ -257,7 +209,7 @@ private:
 
     //io impl methods and members
     std::vector<uhd::transport::udp_zero_copy::sptr> _data_transports;
-    const usrp2_io_helper _io_helper;
+    uhd::otw_type_t _rx_otw_type, _tx_otw_type;
     UHD_PIMPL_DECL(io_impl) _io_impl;
     void io_init(void);
 };
diff --git a/host/lib/usrp/usrp_e/CMakeLists.txt b/host/lib/usrp/usrp_e/CMakeLists.txt
index fbcd19276..6c5d281dd 100644
--- a/host/lib/usrp/usrp_e/CMakeLists.txt
+++ b/host/lib/usrp/usrp_e/CMakeLists.txt
@@ -56,6 +56,7 @@ IF(ENABLE_USRP_E)
         ${CMAKE_SOURCE_DIR}/lib/usrp/usrp_e/usrp_e_impl.hpp
         ${CMAKE_SOURCE_DIR}/lib/usrp/usrp_e/usrp_e_iface.cpp
         ${CMAKE_SOURCE_DIR}/lib/usrp/usrp_e/usrp_e_iface.hpp
+        ${CMAKE_SOURCE_DIR}/lib/usrp/usrp_e/usrp_e_mmap_zero_copy.cpp
         ${CMAKE_SOURCE_DIR}/lib/usrp/usrp_e/usrp_e_regs.hpp
     )
 ELSE(ENABLE_USRP_E)
diff --git a/host/lib/usrp/usrp_e/dboard_iface.cpp b/host/lib/usrp/usrp_e/dboard_iface.cpp
index 1bd177f60..6898df8df 100644
--- a/host/lib/usrp/usrp_e/dboard_iface.cpp
+++ b/host/lib/usrp/usrp_e/dboard_iface.cpp
@@ -91,6 +91,7 @@ public:
     std::vector<double> get_clock_rates(unit_t);
     double get_clock_rate(unit_t);
     void set_clock_enabled(unit_t, bool);
+    double get_codec_rate(unit_t);
 
 private:
     usrp_e_iface::sptr _iface;
@@ -140,6 +141,10 @@ void usrp_e_dboard_iface::set_clock_enabled(unit_t unit, bool enb){
     }
 }
 
+double usrp_e_dboard_iface::get_codec_rate(unit_t){
+    return _clock->get_fpga_clock_rate();
+}
+
 /***********************************************************************
  * GPIO
  **********************************************************************/
diff --git a/host/lib/usrp/usrp_e/dboard_impl.cpp b/host/lib/usrp/usrp_e/dboard_impl.cpp
index d4a27cb72..f2840dcfc 100644
--- a/host/lib/usrp/usrp_e/dboard_impl.cpp
+++ b/host/lib/usrp/usrp_e/dboard_impl.cpp
@@ -87,6 +87,7 @@ void usrp_e_impl::rx_dboard_get(const wax::obj &key_, wax::obj &val){
 
     case DBOARD_PROP_GAIN_GROUP:
         val = make_gain_group(
+            _rx_db_eeprom.id,
             _dboard_manager->get_rx_subdev(key.name),
             _rx_codec_proxy->get_link(),
             GAIN_GROUP_POLICY_RX
@@ -145,6 +146,7 @@ void usrp_e_impl::tx_dboard_get(const wax::obj &key_, wax::obj &val){
 
     case DBOARD_PROP_GAIN_GROUP:
         val = make_gain_group(
+            _tx_db_eeprom.id,
             _dboard_manager->get_tx_subdev(key.name),
             _tx_codec_proxy->get_link(),
             GAIN_GROUP_POLICY_TX
diff --git a/host/lib/usrp/usrp_e/dsp_impl.cpp b/host/lib/usrp/usrp_e/dsp_impl.cpp
index 9312bb603..97f173c1a 100644
--- a/host/lib/usrp/usrp_e/dsp_impl.cpp
+++ b/host/lib/usrp/usrp_e/dsp_impl.cpp
@@ -65,11 +65,11 @@ void usrp_e_impl::rx_ddc_get(const wax::obj &key_, wax::obj &val){
         return;
 
     case DSP_PROP_CODEC_RATE:
-        val = MASTER_CLOCK_RATE;
+        val = _clock_ctrl->get_fpga_clock_rate();
         return;
 
     case DSP_PROP_HOST_RATE:
-        val = MASTER_CLOCK_RATE/_ddc_decim;
+        val = _clock_ctrl->get_fpga_clock_rate()/_ddc_decim;
         return;
 
     default: UHD_THROW_PROP_GET_ERROR();
@@ -87,7 +87,7 @@ void usrp_e_impl::rx_ddc_set(const wax::obj &key_, const wax::obj &val){
     case DSP_PROP_FREQ_SHIFT:{
             double new_freq = val.as<double>();
             _iface->poke32(UE_REG_DSP_RX_FREQ,
-                dsp_type1::calc_cordic_word_and_update(new_freq, MASTER_CLOCK_RATE)
+                dsp_type1::calc_cordic_word_and_update(new_freq, _clock_ctrl->get_fpga_clock_rate())
             );
             _ddc_freq = new_freq; //shadow
         }
@@ -95,7 +95,7 @@ void usrp_e_impl::rx_ddc_set(const wax::obj &key_, const wax::obj &val){
 
     case DSP_PROP_HOST_RATE:{
             //set the decimation
-            _ddc_decim = rint(MASTER_CLOCK_RATE/val.as<double>());
+            _ddc_decim = rint(_clock_ctrl->get_fpga_clock_rate()/val.as<double>());
             _iface->poke32(UE_REG_DSP_RX_DECIM_RATE, dsp_type1::calc_cic_filter_word(_ddc_decim));
 
             //set the scaling
@@ -148,11 +148,11 @@ void usrp_e_impl::tx_duc_get(const wax::obj &key_, wax::obj &val){
         return;
 
     case DSP_PROP_CODEC_RATE:
-        val = MASTER_CLOCK_RATE;
+        val = _clock_ctrl->get_fpga_clock_rate();
         return;
 
     case DSP_PROP_HOST_RATE:
-        val = MASTER_CLOCK_RATE/_duc_interp;
+        val = _clock_ctrl->get_fpga_clock_rate()/_duc_interp;
         return;
 
     default: UHD_THROW_PROP_GET_ERROR();
@@ -170,14 +170,14 @@ void usrp_e_impl::tx_duc_set(const wax::obj &key_, const wax::obj &val){
     case DSP_PROP_FREQ_SHIFT:{
             double new_freq = val.as<double>();
             _iface->poke32(UE_REG_DSP_TX_FREQ,
-                dsp_type1::calc_cordic_word_and_update(new_freq, MASTER_CLOCK_RATE)
+                dsp_type1::calc_cordic_word_and_update(new_freq, _clock_ctrl->get_fpga_clock_rate())
             );
             _duc_freq = new_freq; //shadow
         }
         return;
 
     case DSP_PROP_HOST_RATE:{
-            _duc_interp = rint(MASTER_CLOCK_RATE/val.as<double>());
+            _duc_interp = rint(_clock_ctrl->get_fpga_clock_rate()/val.as<double>());
 
             //set the interpolation
             _iface->poke32(UE_REG_DSP_TX_INTERP_RATE, dsp_type1::calc_cic_filter_word(_duc_interp));
diff --git a/host/lib/usrp/usrp_e/fpga-downloader.cc b/host/lib/usrp/usrp_e/fpga-downloader.cc
index ff8671e98..b0d56e856 100644
--- a/host/lib/usrp/usrp_e/fpga-downloader.cc
+++ b/host/lib/usrp/usrp_e/fpga-downloader.cc
@@ -15,11 +15,14 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
+#include <uhd/config.hpp>
+
 #include <iostream>
 #include <sstream>
 #include <fstream>
 #include <string>
 #include <cstdlib>
+#include <stdexcept>
 
 #include <fcntl.h>
 #include <sys/types.h>
@@ -82,8 +85,9 @@ gpio::gpio(unsigned int gpio_num, gpio_direction pin_direction)
 	std::fstream export_file;
 
 	export_file.open("/sys/class/gpio/export", std::ios::out);
-	if (!export_file.is_open())  ///\todo Poor error handling
-		std::cout << "Failed to open gpio export file." << std::endl;
+	if (not export_file.is_open()) throw std::runtime_error(
+		"Failed to open gpio export file."
+	);
 
 	export_file << gpio_num << std::endl;
 
@@ -92,15 +96,17 @@ gpio::gpio(unsigned int gpio_num, gpio_direction pin_direction)
 	std::fstream direction_file;
 	std::string direction_file_name;
 
-	direction_file_name = base_path.str() + "/direction";
+	if (gpio_num != 114) {
+		direction_file_name = base_path.str() + "/direction";
 
-	direction_file.open(direction_file_name.c_str()); 
-	if (!direction_file.is_open())
-		std::cout << "Failed to open direction file." << std::endl;
-	if (pin_direction == OUT)
-		direction_file << "out" << std::endl;
-	else
-		direction_file << "in" << std::endl;
+		direction_file.open(direction_file_name.c_str());
+		if (!direction_file.is_open())
+			std::cout << "Failed to open direction file." << std::endl;
+		if (pin_direction == OUT)
+			direction_file << "out" << std::endl;
+		else
+			direction_file << "in" << std::endl;
+	}
 
 	std::string value_file_name;
 
@@ -251,11 +257,11 @@ void usrp_e_load_fpga(const std::string &bin_file){
 	gpio gpio_init_b(INIT_B, IN);
 	gpio gpio_done  (DONE,   IN);
 
-	std::cout << "FPGA config file: " << bin_file << std::endl;
+	std::cout << "Loading FPGA image: " << bin_file << "... " << std::flush;
 
 	prepare_fpga_for_configuration(gpio_prog_b, gpio_init_b);
 
-	std::cout << "Done = " << gpio_done.get_value() << std::endl;
+	std::cout << "done = " << gpio_done.get_value() << std::endl;
 
 	send_file_to_fpga(bin_file, gpio_init_b, gpio_done);
 }
diff --git a/host/lib/usrp/usrp_e/io_impl.cpp b/host/lib/usrp/usrp_e/io_impl.cpp
index 31ea4c6c0..9996e7172 100644
--- a/host/lib/usrp/usrp_e/io_impl.cpp
+++ b/host/lib/usrp/usrp_e/io_impl.cpp
@@ -22,8 +22,6 @@
 #include <uhd/transport/bounded_buffer.hpp>
 #include "../../transport/vrt_packet_handler.hpp"
 #include <boost/bind.hpp>
-#include <fcntl.h> //read, write
-#include <poll.h>
 #include <boost/format.hpp>
 #include <boost/thread.hpp>
 #include <iostream>
@@ -32,88 +30,14 @@ using namespace uhd;
 using namespace uhd::usrp;
 using namespace uhd::transport;
 
+zero_copy_if::sptr usrp_e_make_mmap_zero_copy(usrp_e_iface::sptr iface);
+
 /***********************************************************************
  * Constants
  **********************************************************************/
-static const size_t MAX_BUFF_SIZE = 2048;
-static const bool usrp_e_io_impl_verbose = false;
 static const size_t tx_async_report_sid = 1;
 static const int underflow_flags = async_metadata_t::EVENT_CODE_UNDERFLOW | async_metadata_t::EVENT_CODE_UNDERFLOW_IN_PACKET;
-
-/***********************************************************************
- * Data Transport (phony zero-copy with read/write)
- **********************************************************************/
-class data_transport:
-    public transport::phony_zero_copy_recv_if,
-    public transport::phony_zero_copy_send_if
-{
-public:
-    data_transport(int fd):
-        transport::phony_zero_copy_recv_if(MAX_BUFF_SIZE),
-        transport::phony_zero_copy_send_if(MAX_BUFF_SIZE),
-        _fd(fd)
-    {
-        /* NOP */
-    }
-
-    size_t get_num_recv_frames(void) const{
-        return 100; //FIXME no idea!
-        //this will be an important number when packet ring gets implemented
-    }
-
-    size_t get_num_send_frames(void) const{
-        return 100; //FIXME no idea!
-        //this will be an important number when packet ring gets implemented
-    }
-
-private:
-    int _fd;
-    ssize_t send(const boost::asio::const_buffer &buff){
-        return write(_fd,
-            boost::asio::buffer_cast<const void *>(buff),
-            boost::asio::buffer_size(buff)
-        );
-    }
-    ssize_t recv(const boost::asio::mutable_buffer &buff){
-        //std::cout << boost::format(
-        //    "calling read on fd %d, buff size is %d"
-        //) % _fd % boost::asio::buffer_size(buff) << std::endl;
-
-        //setup and call poll on the file descriptor
-        //return 0 and do not read when poll times out
-        pollfd pfd;
-        pfd.fd = _fd;
-        pfd.events = POLLIN;
-        ssize_t poll_ret = poll(&pfd, 1, 100/*ms*/);
-        if (poll_ret <= 0){
-            if (usrp_e_io_impl_verbose) std::cerr << boost::format(
-                "usrp-e io impl recv(): poll() returned non-positive value: %d\n"
-                "    -> return 0 for timeout"
-            ) % poll_ret << std::endl;
-            return 0; //timeout
-        }
-
-        //perform the blocking read(...)
-        ssize_t read_ret = read(_fd,
-            boost::asio::buffer_cast<void *>(buff),
-            boost::asio::buffer_size(buff)
-        );
-        if (read_ret < 0){
-            if (usrp_e_io_impl_verbose) std::cerr << boost::format(
-                "usrp-e io impl recv(): read() returned small value: %d\n"
-                "    -> return -1 for error"
-            ) % read_ret << std::endl;
-            return -1;
-        }
-
-        //std::cout << "len " << int(read_ret) << std::endl;
-        //for (size_t i = 0; i < 9; i++){
-        //    std::cout << boost::format("    0x%08x") % boost::asio::buffer_cast<boost::uint32_t *>(buff)[i] << std::endl;
-        //}
-
-        return read_ret;
-    }
-};
+static const bool recv_debug = false;
 
 /***********************************************************************
  * io impl details (internal to this file)
@@ -126,11 +50,11 @@ struct usrp_e_impl::io_impl{
     //state management for the vrt packet handler code
     vrt_packet_handler::recv_state packet_handler_recv_state;
     vrt_packet_handler::send_state packet_handler_send_state;
-    data_transport transport;
+    zero_copy_if::sptr data_xport;
     bool continuous_streaming;
-    io_impl(int fd):
-        transport(fd),
-        recv_pirate_booty(recv_booty_type::make(transport.get_num_recv_frames())),
+    io_impl(usrp_e_iface::sptr iface):
+        data_xport(usrp_e_make_mmap_zero_copy(iface)),
+        recv_pirate_booty(recv_booty_type::make(data_xport->get_num_recv_frames())),
         async_msg_fifo(bounded_buffer<async_metadata_t>::make(100/*messages deep*/))
     {
         /* NOP */
@@ -142,14 +66,14 @@ struct usrp_e_impl::io_impl{
         recv_pirate_crew.join_all();
     }
 
-    bool get_recv_buffs(vrt_packet_handler::managed_recv_buffs_t &buffs, size_t timeout_ms){
+    bool get_recv_buffs(vrt_packet_handler::managed_recv_buffs_t &buffs, double timeout){
         UHD_ASSERT_THROW(buffs.size() == 1);
         boost::this_thread::disable_interruption di; //disable because the wait can throw
-        return recv_pirate_booty->pop_with_timed_wait(buffs.front(), boost::posix_time::milliseconds(timeout_ms));
+        return recv_pirate_booty->pop_with_timed_wait(buffs.front(), timeout);
     }
 
     //a pirate's life is the life for me!
-    void recv_pirate_loop();
+    void recv_pirate_loop(usrp_e_clock_ctrl::sptr);
     typedef bounded_buffer<managed_recv_buffer::sptr> recv_booty_type;
     recv_booty_type::sptr recv_pirate_booty;
     bounded_buffer<async_metadata_t>::sptr async_msg_fifo;
@@ -162,17 +86,23 @@ struct usrp_e_impl::io_impl{
  * - while raiding, loot for recv buffers
  * - put booty into the alignment buffer
  **********************************************************************/
-void usrp_e_impl::io_impl::recv_pirate_loop(
-
-){
+void usrp_e_impl::io_impl::recv_pirate_loop(usrp_e_clock_ctrl::sptr clock_ctrl)
+{
     set_thread_priority_safe();
     recv_pirate_crew_raiding = true;
-    //size_t next_packet_seq = 0;
 
     while(recv_pirate_crew_raiding){
-        managed_recv_buffer::sptr buff = this->transport.get_recv_buff();
+        managed_recv_buffer::sptr buff = this->data_xport->get_recv_buff();
         if (not buff.get()) continue; //ignore timeout/error buffers
 
+        if (recv_debug){
+            std::cout << "len " << buff->size() << std::endl;
+            for (size_t i = 0; i < 9; i++){
+                std::cout << boost::format("    0x%08x") % buff->cast<const boost::uint32_t *>()[i] << std::endl;
+            }
+            std::cout << std::endl << std::endl;
+        }
+
         try{
             //extract the vrt header packet info
             vrt::if_packet_info_t if_packet_info;
@@ -188,7 +118,7 @@ void usrp_e_impl::io_impl::recv_pirate_loop(
                 metadata.channel = 0;
                 metadata.has_time_spec = if_packet_info.has_tsi and if_packet_info.has_tsf;
                 metadata.time_spec = time_spec_t(
-                    time_t(if_packet_info.tsi), size_t(if_packet_info.tsf), MASTER_CLOCK_RATE
+                    time_t(if_packet_info.tsi), size_t(if_packet_info.tsf), clock_ctrl->get_fpga_clock_rate()
                 );
                 metadata.event_code = vrt_packet_handler::get_context_code<async_metadata_t::event_code_t>(vrt_hdr, if_packet_info);
 
@@ -198,12 +128,12 @@ void usrp_e_impl::io_impl::recv_pirate_loop(
                 continue;
             }
 
+            //same number of frames as the data transport -> always immediate
+            recv_pirate_booty->push_with_wait(buff);
+
         }catch(const std::exception &e){
             std::cerr << "Error (usrp-e recv pirate loop): " << e.what() << std::endl;
         }
-
-        //usrp-e back-pressures on receive: push with wait
-        recv_pirate_booty->push_with_wait(buff);
     }
 }
 
@@ -211,6 +141,15 @@ void usrp_e_impl::io_impl::recv_pirate_loop(
  * Helper Functions
  **********************************************************************/
 void usrp_e_impl::io_init(void){
+    //setup otw types
+    _send_otw_type.width = 16;
+    _send_otw_type.shift = 0;
+    _send_otw_type.byteorder = otw_type_t::BO_LITTLE_ENDIAN;
+
+    _recv_otw_type.width = 16;
+    _recv_otw_type.shift = 0;
+    _recv_otw_type.byteorder = otw_type_t::BO_LITTLE_ENDIAN;
+
     //setup rx data path
     _iface->poke32(UE_REG_CTRL_RX_NSAMPS_PER_PKT, get_max_recv_samps_per_packet());
     _iface->poke32(UE_REG_CTRL_RX_NCHANNELS, 1);
@@ -228,11 +167,11 @@ void usrp_e_impl::io_init(void){
     _iface->poke32(UE_REG_CTRL_TX_REPORT_SID, tx_async_report_sid);
     _iface->poke32(UE_REG_CTRL_TX_POLICY, UE_FLAG_CTRL_TX_POLICY_NEXT_PACKET);
 
-    _io_impl = UHD_PIMPL_MAKE(io_impl, (_iface->get_file_descriptor()));
+    _io_impl = UHD_PIMPL_MAKE(io_impl, (_iface));
 
     //spawn a pirate, yarrr!
     _io_impl->recv_pirate_crew.create_thread(boost::bind(
-        &usrp_e_impl::io_impl::recv_pirate_loop, _io_impl.get()
+        &usrp_e_impl::io_impl::recv_pirate_loop, _io_impl.get(), _clock_ctrl
     ));
 }
 
@@ -242,7 +181,7 @@ void usrp_e_impl::issue_stream_cmd(const stream_cmd_t &stream_cmd){
         stream_cmd, get_max_recv_samps_per_packet()
     ));
     _iface->poke32(UE_REG_CTRL_RX_TIME_SECS,  boost::uint32_t(stream_cmd.time_spec.get_full_secs()));
-    _iface->poke32(UE_REG_CTRL_RX_TIME_TICKS, stream_cmd.time_spec.get_tick_count(MASTER_CLOCK_RATE));
+    _iface->poke32(UE_REG_CTRL_RX_TIME_TICKS, stream_cmd.time_spec.get_tick_count(_clock_ctrl->get_fpga_clock_rate()));
 }
 
 void usrp_e_impl::handle_overrun(size_t){
@@ -257,34 +196,38 @@ void usrp_e_impl::handle_overrun(size_t){
  * Data Send
  **********************************************************************/
 bool get_send_buffs(
-    data_transport *trans,
+    zero_copy_if::sptr trans, double timeout,
     vrt_packet_handler::managed_send_buffs_t &buffs
 ){
     UHD_ASSERT_THROW(buffs.size() == 1);
-    buffs[0] = trans->get_send_buff();
-    return buffs[0].get();
+    buffs[0] = trans->get_send_buff(timeout);
+    return buffs[0].get() != NULL;
 }
 
+#if 0
+size_t usrp_e_impl::get_max_send_samps_per_packet(void) const{
+    static const size_t hdr_size = 0
+        + vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
+        - sizeof(vrt::if_packet_info_t().cid) //no class id ever used
+    ;
+    size_t bpp = _io_impl->data_xport->get_send_frame_size() - hdr_size;
+    return bpp/_send_otw_type.get_sample_size();
+}
+#endif
+
 size_t usrp_e_impl::send(
-    const std::vector<const void *> &buffs,
-    size_t num_samps,
-    const tx_metadata_t &metadata,
-    const io_type_t &io_type,
-    send_mode_t send_mode
+    const std::vector<const void *> &buffs, size_t num_samps,
+    const tx_metadata_t &metadata, const io_type_t &io_type,
+    send_mode_t send_mode, double timeout
 ){
-    otw_type_t send_otw_type;
-    send_otw_type.width = 16;
-    send_otw_type.shift = 0;
-    send_otw_type.byteorder = otw_type_t::BO_LITTLE_ENDIAN;
-
     return vrt_packet_handler::send(
         _io_impl->packet_handler_send_state,       //last state of the send handler
         buffs, num_samps,                          //buffer to fill
         metadata, send_mode,                       //samples metadata
-        io_type, send_otw_type,                    //input and output types to convert
-        MASTER_CLOCK_RATE,                         //master clock tick rate
+        io_type, _send_otw_type,                   //input and output types to convert
+        _clock_ctrl->get_fpga_clock_rate(),        //master clock tick rate
         uhd::transport::vrt::if_hdr_pack_le,
-        boost::bind(&get_send_buffs, &_io_impl->transport, _1),
+        boost::bind(&get_send_buffs, _io_impl->data_xport, timeout, _1),
         get_max_send_samps_per_packet()
     );
 }
@@ -292,36 +235,31 @@ size_t usrp_e_impl::send(
 /***********************************************************************
  * Data Recv
  **********************************************************************/
-bool get_recv_buffs(
-    data_transport *trans,
-    vrt_packet_handler::managed_recv_buffs_t &buffs
-){
-    UHD_ASSERT_THROW(buffs.size() == 1);
-    buffs[0] = trans->get_recv_buff();
-    return buffs[0].get();
+#if 0
+size_t usrp_e_impl::get_max_recv_samps_per_packet(void) const{
+    static const size_t hdr_size = 0
+        + vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
+        + sizeof(vrt::if_packet_info_t().tlr) //forced to have trailer
+        - sizeof(vrt::if_packet_info_t().cid) //no class id ever used
+    ;
+    size_t bpp = _io_impl->data_xport->get_recv_frame_size() - hdr_size;
+    return bpp/_recv_otw_type.get_sample_size();
 }
+#endif
 
 size_t usrp_e_impl::recv(
-    const std::vector<void *> &buffs,
-    size_t num_samps,
-    rx_metadata_t &metadata,
-    const io_type_t &io_type,
-    recv_mode_t recv_mode,
-    size_t timeout_ms
+    const std::vector<void *> &buffs, size_t num_samps,
+    rx_metadata_t &metadata, const io_type_t &io_type,
+    recv_mode_t recv_mode, double timeout
 ){
-    otw_type_t recv_otw_type;
-    recv_otw_type.width = 16;
-    recv_otw_type.shift = 0;
-    recv_otw_type.byteorder = otw_type_t::BO_LITTLE_ENDIAN;
-
     return vrt_packet_handler::recv(
         _io_impl->packet_handler_recv_state,       //last state of the recv handler
         buffs, num_samps,                          //buffer to fill
         metadata, recv_mode,                       //samples metadata
-        io_type, recv_otw_type,                    //input and output types to convert
-        MASTER_CLOCK_RATE,                         //master clock tick rate
+        io_type, _recv_otw_type,                   //input and output types to convert
+        _clock_ctrl->get_fpga_clock_rate(),        //master clock tick rate
         uhd::transport::vrt::if_hdr_unpack_le,
-        boost::bind(&usrp_e_impl::io_impl::get_recv_buffs, _io_impl.get(), _1, timeout_ms),
+        boost::bind(&usrp_e_impl::io_impl::get_recv_buffs, _io_impl.get(), _1, timeout),
         boost::bind(&usrp_e_impl::handle_overrun, this, _1)
     );
 }
@@ -330,11 +268,8 @@ size_t usrp_e_impl::recv(
  * Async Recv
  **********************************************************************/
 bool usrp_e_impl::recv_async_msg(
-    async_metadata_t &async_metadata,
-    size_t timeout_ms
+    async_metadata_t &async_metadata, double timeout
 ){
     boost::this_thread::disable_interruption di; //disable because the wait can throw
-    return _io_impl->async_msg_fifo->pop_with_timed_wait(
-        async_metadata, boost::posix_time::milliseconds(timeout_ms)
-    );
+    return _io_impl->async_msg_fifo->pop_with_timed_wait(async_metadata, timeout);
 }
diff --git a/host/lib/usrp/usrp_e/mboard_impl.cpp b/host/lib/usrp/usrp_e/mboard_impl.cpp
index 3d4cef069..f0118aa4b 100644
--- a/host/lib/usrp/usrp_e/mboard_impl.cpp
+++ b/host/lib/usrp/usrp_e/mboard_impl.cpp
@@ -125,7 +125,7 @@ void usrp_e_impl::mboard_set(const wax::obj &key, const wax::obj &val){
     case MBOARD_PROP_TIME_NOW:
     case MBOARD_PROP_TIME_NEXT_PPS:{
             time_spec_t time_spec = val.as<time_spec_t>();
-            _iface->poke32(UE_REG_TIME64_TICKS, time_spec.get_tick_count(MASTER_CLOCK_RATE));
+            _iface->poke32(UE_REG_TIME64_TICKS, time_spec.get_tick_count(_clock_ctrl->get_fpga_clock_rate()));
             boost::uint32_t imm_flags = (key.as<mboard_prop_t>() == MBOARD_PROP_TIME_NOW)? 1 : 0;
             _iface->poke32(UE_REG_TIME64_IMM, imm_flags);
             _iface->poke32(UE_REG_TIME64_SECS, time_spec.get_full_secs());
diff --git a/host/lib/usrp/usrp_e/usrp_e_impl.cpp b/host/lib/usrp/usrp_e/usrp_e_impl.cpp
index 5c0e1dbb0..1b71c0a52 100644
--- a/host/lib/usrp/usrp_e/usrp_e_impl.cpp
+++ b/host/lib/usrp/usrp_e/usrp_e_impl.cpp
@@ -16,13 +16,17 @@
 //
 
 #include "usrp_e_impl.hpp"
+#include "usrp_e_regs.hpp"
 #include <uhd/usrp/device_props.hpp>
 #include <uhd/usrp/mboard_props.hpp>
 #include <uhd/utils/assert.hpp>
 #include <uhd/utils/static.hpp>
+#include <uhd/utils/images.hpp>
 #include <boost/format.hpp>
 #include <boost/filesystem.hpp>
+#include <boost/functional/hash.hpp>
 #include <iostream>
+#include <fstream>
 
 using namespace uhd;
 using namespace uhd::usrp;
@@ -66,7 +70,61 @@ static device_addrs_t usrp_e_find(const device_addr_t &hint){
  * Make
  **********************************************************************/
 static device::sptr usrp_e_make(const device_addr_t &device_addr){
-    return device::sptr(new usrp_e_impl(device_addr["node"]));
+
+    //setup the main interface into fpga
+    std::string node = device_addr["node"];
+    std::cout << boost::format("Opening USRP-E on %s") % node << std::endl;
+    usrp_e_iface::sptr iface = usrp_e_iface::make(node);
+
+    //------------------------------------------------------------------
+    //-- Handle the FPGA loading...
+    //-- The image can be confimed as already loaded when:
+    //--   1) The compatibility number matches.
+    //--   2) The hash in the hash-file matches.
+    //------------------------------------------------------------------
+    static const char *hash_file_path = "/tmp/usrp_e100_hash";
+
+    //extract the fpga path for usrp-e
+    std::string usrp_e_fpga_image = find_image_path(
+        device_addr.has_key("fpga")? device_addr["fpga"] : "usrp_e100_fpga.bin"
+    );
+
+    //calculate a hash of the fpga file
+    size_t fpga_hash = 0;
+    {
+        std::ifstream file(usrp_e_fpga_image.c_str());
+        if (not file.good()) throw std::runtime_error(
+            "cannot open fpga file for read: " + usrp_e_fpga_image
+        );
+        do{
+            boost::hash_combine(fpga_hash, file.get());
+        } while (file.good());
+        file.close();
+    }
+
+    //read the compatibility number
+    boost::uint16_t fpga_compat_num = iface->peek16(UE_REG_MISC_COMPAT);
+
+    //read the hash in the hash-file
+    size_t loaded_hash = 0;
+    try{std::ifstream(hash_file_path) >> loaded_hash;}catch(...){}
+
+    //if not loaded: load the fpga image and write the hash-file
+    if (fpga_compat_num != USRP_E_COMPAT_NUM or loaded_hash != fpga_hash){
+        usrp_e_load_fpga(usrp_e_fpga_image);
+        try{std::ofstream(hash_file_path) << fpga_hash;}catch(...){}
+    }
+
+    //check that the compatibility is correct
+    fpga_compat_num = iface->peek16(UE_REG_MISC_COMPAT);
+    if (fpga_compat_num != USRP_E_COMPAT_NUM){
+        throw std::runtime_error(str(boost::format(
+            "Expected fpga compatibility number 0x%x, but got 0x%x:\n"
+            "The fpga build is not compatible with the host code build."
+        ) % USRP_E_COMPAT_NUM % fpga_compat_num));
+    }
+
+    return device::sptr(new usrp_e_impl(iface));
 }
 
 UHD_STATIC_BLOCK(register_usrp_e_device){
@@ -76,11 +134,9 @@ UHD_STATIC_BLOCK(register_usrp_e_device){
 /***********************************************************************
  * Structors
  **********************************************************************/
-usrp_e_impl::usrp_e_impl(const std::string &node){
-    std::cout << boost::format("Opening USRP-E on %s") % node << std::endl;
+usrp_e_impl::usrp_e_impl(usrp_e_iface::sptr iface): _iface(iface){
 
-    //setup various interfaces into hardware
-    _iface = usrp_e_iface::make(node);
+    //setup interfaces into hardware
     _clock_ctrl = usrp_e_clock_ctrl::make(_iface);
     _codec_ctrl = usrp_e_codec_ctrl::make(_iface);
 
diff --git a/host/lib/usrp/usrp_e/usrp_e_impl.hpp b/host/lib/usrp/usrp_e/usrp_e_impl.hpp
index 2457e27cc..e55b46b80 100644
--- a/host/lib/usrp/usrp_e/usrp_e_impl.hpp
+++ b/host/lib/usrp/usrp_e/usrp_e_impl.hpp
@@ -22,6 +22,7 @@
 #include <uhd/utils/pimpl.hpp>
 #include <uhd/usrp/subdev_spec.hpp>
 #include <uhd/usrp/dboard_eeprom.hpp>
+#include <uhd/types/otw_type.hpp>
 #include <uhd/types/clock_config.hpp>
 #include <uhd/types/stream_cmd.hpp>
 #include <uhd/usrp/dboard_manager.hpp>
@@ -29,7 +30,7 @@
 #ifndef INCLUDED_USRP_E_IMPL_HPP
 #define INCLUDED_USRP_E_IMPL_HPP
 
-static const double MASTER_CLOCK_RATE = 64e6; //TODO get from clock control
+static const boost::uint16_t USRP_E_COMPAT_NUM = 0x02;
 
 //! load an fpga image from a bin file into the usrp-e fpga
 extern void usrp_e_load_fpga(const std::string &bin_file);
@@ -78,25 +79,28 @@ private:
 class usrp_e_impl : public uhd::device{
 public:
     //structors
-    usrp_e_impl(const std::string &node);
+    usrp_e_impl(usrp_e_iface::sptr);
     ~usrp_e_impl(void);
 
     //the io interface
-    size_t send(const std::vector<const void *> &, size_t, const uhd::tx_metadata_t &, const uhd::io_type_t &, send_mode_t);
-    size_t recv(const std::vector<void *> &, size_t, uhd::rx_metadata_t &, const uhd::io_type_t &, recv_mode_t, size_t);
-    bool recv_async_msg(uhd::async_metadata_t &, size_t);
+    size_t send(const std::vector<const void *> &, size_t, const uhd::tx_metadata_t &, const uhd::io_type_t &, send_mode_t, double);
+    size_t recv(const std::vector<void *> &, size_t, uhd::rx_metadata_t &, const uhd::io_type_t &, recv_mode_t, double);
+    bool recv_async_msg(uhd::async_metadata_t &, double);
+#if 0
+    size_t get_max_send_samps_per_packet(void) const;
+    size_t get_max_recv_samps_per_packet(void) const;
+#else
     size_t get_max_send_samps_per_packet(void) const{return 503;}
     size_t get_max_recv_samps_per_packet(void) const{return 503;}
+#endif
 
 private:
     //interface to ioctls and file descriptor
     usrp_e_iface::sptr _iface;
 
-    //FIXME fetch from ioctl?
-    static const size_t _max_num_samples = 2048/sizeof(boost::uint32_t);
-
     //handle io stuff
     UHD_PIMPL_DECL(io_impl) _io_impl;
+    uhd::otw_type_t _send_otw_type, _recv_otw_type;
     void io_init(void);
     void issue_stream_cmd(const uhd::stream_cmd_t &stream_cmd);
     void handle_overrun(size_t);
diff --git a/host/lib/usrp/usrp_e/usrp_e_mmap_zero_copy.cpp b/host/lib/usrp/usrp_e/usrp_e_mmap_zero_copy.cpp
new file mode 100644
index 000000000..274bb043e
--- /dev/null
+++ b/host/lib/usrp/usrp_e/usrp_e_mmap_zero_copy.cpp
@@ -0,0 +1,215 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "usrp_e_iface.hpp"
+#include <uhd/transport/zero_copy.hpp>
+#include <uhd/utils/assert.hpp>
+#include <linux/usrp_e.h>
+#include <sys/mman.h> //mmap
+#include <unistd.h> //getpagesize
+#include <poll.h> //poll
+#include <boost/bind.hpp>
+#include <boost/enable_shared_from_this.hpp>
+#include <iostream>
+
+using namespace uhd;
+using namespace uhd::transport;
+
+static const bool fp_verbose = false; //fast-path verbose
+static const bool sp_verbose = false; //slow-path verbose
+static const size_t poll_breakout = 10; //how many poll timeouts constitute a full timeout
+
+/***********************************************************************
+ * The zero copy interface implementation
+ **********************************************************************/
+class usrp_e_mmap_zero_copy_impl : public zero_copy_if, public boost::enable_shared_from_this<usrp_e_mmap_zero_copy_impl> {
+public:
+    usrp_e_mmap_zero_copy_impl(usrp_e_iface::sptr iface):
+        _fd(iface->get_file_descriptor()), _recv_index(0), _send_index(0)
+    {
+        //get system sizes
+        iface->ioctl(USRP_E_GET_RB_INFO, &_rb_size);
+        size_t page_size = getpagesize();
+        _frame_size = page_size/2;
+
+        //calculate the memory size
+        _map_size =
+            (_rb_size.num_pages_rx_flags + _rb_size.num_pages_tx_flags) * page_size +
+            (_rb_size.num_rx_frames + _rb_size.num_tx_frames) * _frame_size;
+
+        //print sizes summary
+        if (sp_verbose){
+            std::cout << "page_size:          " << page_size                   << std::endl;
+            std::cout << "frame_size:         " << _frame_size                 << std::endl;
+            std::cout << "num_pages_rx_flags: " << _rb_size.num_pages_rx_flags << std::endl;
+            std::cout << "num_rx_frames:      " << _rb_size.num_rx_frames      << std::endl;
+            std::cout << "num_pages_tx_flags: " << _rb_size.num_pages_tx_flags << std::endl;
+            std::cout << "num_tx_frames:      " << _rb_size.num_tx_frames      << std::endl;
+            std::cout << "map_size:           " << _map_size                   << std::endl;
+        }
+
+        //call mmap to get the memory
+        _mapped_mem = ::mmap(
+            NULL, _map_size, PROT_READ | PROT_WRITE, MAP_SHARED, _fd, 0
+        );
+        UHD_ASSERT_THROW(_mapped_mem != MAP_FAILED);
+
+        //calculate the memory offsets for info and buffers
+        size_t recv_info_off = 0;
+        size_t recv_buff_off = recv_info_off + (_rb_size.num_pages_rx_flags * page_size);
+        size_t send_info_off = recv_buff_off + (_rb_size.num_rx_frames * _frame_size);
+        size_t send_buff_off = send_info_off + (_rb_size.num_pages_tx_flags * page_size);
+
+        //print offset summary
+        if (sp_verbose){
+            std::cout << "recv_info_off: " << recv_info_off << std::endl;
+            std::cout << "recv_buff_off: " << recv_buff_off << std::endl;
+            std::cout << "send_info_off: " << send_info_off << std::endl;
+            std::cout << "send_buff_off: " << send_buff_off << std::endl;
+        }
+
+        //set the internal pointers for info and buffers
+        typedef ring_buffer_info (*rbi_pta)[];
+        char *rb_ptr = reinterpret_cast<char *>(_mapped_mem);
+        _recv_info = reinterpret_cast<rbi_pta>(rb_ptr + recv_info_off);
+        _recv_buff = rb_ptr + recv_buff_off;
+        _send_info = reinterpret_cast<rbi_pta>(rb_ptr + send_info_off);
+        _send_buff = rb_ptr + send_buff_off;
+    }
+
+    ~usrp_e_mmap_zero_copy_impl(void){
+        if (sp_verbose) std::cout << "cleanup: munmap" << std::endl;
+        ::munmap(_mapped_mem, _map_size);
+    }
+
+    managed_recv_buffer::sptr get_recv_buff(double timeout){
+        if (fp_verbose) std::cout << "get_recv_buff: " << _recv_index << std::endl;
+
+        //grab pointers to the info and buffer
+        ring_buffer_info *info = (*_recv_info) + _recv_index;
+        void *mem = _recv_buff + _frame_size*_recv_index;
+
+        //poll/wait for a ready frame
+        if (not (info->flags & RB_USER)){
+            for (size_t i = 0; i < poll_breakout; i++){
+                pollfd pfd;
+                pfd.fd = _fd;
+                pfd.events = POLLIN;
+                ssize_t poll_ret = ::poll(&pfd, 1, size_t(timeout*1e3/poll_breakout));
+                if (fp_verbose) std::cout << "  POLLIN: " << poll_ret << std::endl;
+                if (poll_ret > 0) goto found_user_frame; //good poll, continue on
+            }
+            return managed_recv_buffer::sptr(); //timed-out for real
+        } found_user_frame:
+
+        //the process has claimed the frame
+        info->flags = RB_USER_PROCESS;
+
+        //increment the index for the next call
+        if (++_recv_index == size_t(_rb_size.num_rx_frames)) _recv_index = 0;
+
+        //return the managed buffer for this frame
+        if (fp_verbose) std::cout << "  make_recv_buff: " << info->len << std::endl;
+        return managed_recv_buffer::make_safe(
+            boost::asio::const_buffer(mem, info->len),
+            boost::bind(&usrp_e_mmap_zero_copy_impl::release, shared_from_this(), info)
+        );
+    }
+
+    size_t get_num_recv_frames(void) const{
+        return _rb_size.num_rx_frames;
+    }
+
+    size_t get_recv_frame_size(void) const{
+        return _frame_size;
+    }
+
+    managed_send_buffer::sptr get_send_buff(double timeout){
+        if (fp_verbose) std::cout << "get_send_buff: " << _send_index << std::endl;
+
+        //grab pointers to the info and buffer
+        ring_buffer_info *info = (*_send_info) + _send_index;
+        void *mem = _send_buff + _frame_size*_send_index;
+
+        //poll/wait for a ready frame
+        if (not (info->flags & RB_KERNEL)){
+            pollfd pfd;
+            pfd.fd = _fd;
+            pfd.events = POLLOUT;
+            ssize_t poll_ret = ::poll(&pfd, 1, size_t(timeout*1e3));
+            if (fp_verbose) std::cout << "  POLLOUT: " << poll_ret << std::endl;
+            if (poll_ret <= 0) return managed_send_buffer::sptr();
+        }
+
+        //increment the index for the next call
+        if (++_send_index == size_t(_rb_size.num_tx_frames)) _send_index = 0;
+
+        //return the managed buffer for this frame
+        if (fp_verbose) std::cout << "  make_send_buff: " << _frame_size << std::endl;
+        return managed_send_buffer::make_safe(
+            boost::asio::mutable_buffer(mem, _frame_size),
+            boost::bind(&usrp_e_mmap_zero_copy_impl::commit, shared_from_this(), info, _1)
+        );
+    }
+
+    size_t get_num_send_frames(void) const{
+        return _rb_size.num_tx_frames;
+    }
+
+    size_t get_send_frame_size(void) const{
+        return _frame_size;
+    }
+
+private:
+
+    void release(ring_buffer_info *info){
+        if (fp_verbose) std::cout << "recv buff: release" << std::endl;
+        info->flags = RB_KERNEL;
+    }
+
+    void commit(ring_buffer_info *info, size_t len){
+        if (fp_verbose) std::cout << "send buff: commit " << len << std::endl;
+        info->len = len;
+        info->flags = RB_USER;
+        if (::write(_fd, NULL, 0) < 0){
+            std::cerr << UHD_THROW_SITE_INFO("write error") << std::endl;
+        }
+    }
+
+    int _fd;
+
+    //the mapped memory itself
+    void *_mapped_mem;
+
+    //mapped memory sizes
+    usrp_e_ring_buffer_size_t _rb_size;
+    size_t _frame_size, _map_size;
+
+    //pointers to sections in the mapped memory
+    ring_buffer_info (*_recv_info)[], (*_send_info)[];
+    char *_recv_buff, *_send_buff;
+
+    //indexes into sub-sections of mapped memory
+    size_t _recv_index, _send_index;
+};
+
+/***********************************************************************
+ * The zero copy interface make function
+ **********************************************************************/
+zero_copy_if::sptr usrp_e_make_mmap_zero_copy(usrp_e_iface::sptr iface){
+    return zero_copy_if::sptr(new usrp_e_mmap_zero_copy_impl(iface));
+}
diff --git a/host/lib/usrp/usrp_e/usrp_e_regs.hpp b/host/lib/usrp/usrp_e/usrp_e_regs.hpp
index a4f42093e..f74358f00 100644
--- a/host/lib/usrp/usrp_e/usrp_e_regs.hpp
+++ b/host/lib/usrp/usrp_e/usrp_e_regs.hpp
@@ -30,7 +30,7 @@
 #define UE_REG_MISC_CGEN_ST    UE_REG_MISC_BASE + 6
 #define UE_REG_MISC_TEST       UE_REG_MISC_BASE + 8
 #define UE_REG_MISC_RX_LEN     UE_REG_MISC_BASE + 10
-#define UE_REG_MISC_TX_LEN     UE_REG_MISC_BASE + 12
+#define UE_REG_MISC_COMPAT     UE_REG_MISC_BASE + 12
 
 /////////////////////////////////////////////////////
 // Slave 1 -- UART
diff --git a/host/lib/usrp/wrapper_utils.hpp b/host/lib/usrp/wrapper_utils.hpp
new file mode 100644
index 000000000..6f9fdbfca
--- /dev/null
+++ b/host/lib/usrp/wrapper_utils.hpp
@@ -0,0 +1,66 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_LIBUHD_USRP_WRAPPER_UTILS_HPP
+#define INCLUDED_LIBUHD_USRP_WRAPPER_UTILS_HPP
+
+#include <uhd/wax.hpp>
+#include <uhd/types/ranges.hpp>
+#include <uhd/usrp/dsp_props.hpp>
+#include <uhd/utils/warning.hpp>
+#include <boost/format.hpp>
+#include <cmath>
+
+static inline uhd::freq_range_t add_dsp_shift(
+    const uhd::freq_range_t &range,
+    wax::obj dsp
+){
+    double codec_rate = dsp[uhd::usrp::DSP_PROP_CODEC_RATE].as<double>();
+    return uhd::freq_range_t(range.min - codec_rate/2.0, range.max + codec_rate/2.0);
+}
+
+static inline void do_samp_rate_warning_message(
+    double target_rate,
+    double actual_rate,
+    const std::string &xx
+){
+    static const double max_allowed_error = 1.0; //Sps
+    if (std::abs(target_rate - actual_rate) > max_allowed_error){
+        uhd::warning::post(str(boost::format(
+            "The hardware does not support the requested %s sample rate:\n"
+            "Target sample rate: %f MSps\n"
+            "Actual sample rate: %f MSps\n"
+        ) % xx % (target_rate/1e6) % (actual_rate/1e6)));
+    }
+}
+
+static inline void do_tune_freq_warning_message(
+    double target_freq,
+    double actual_freq,
+    const std::string &xx
+){
+    static const double max_allowed_error = 1.0; //Hz
+    if (std::abs(target_freq - actual_freq) > max_allowed_error){
+        uhd::warning::post(str(boost::format(
+            "The hardware does not support the requested %s frequency:\n"
+            "Target frequency: %f MHz\n"
+            "Actual frequency: %f MHz\n"
+        ) % xx % (target_freq/1e6) % (actual_freq/1e6)));
+    }
+}
+
+#endif /* INCLUDED_LIBUHD_USRP_WRAPPER_UTILS_HPP */
diff --git a/host/lib/utils/gain_group.cpp b/host/lib/utils/gain_group.cpp
index 078fe56b2..54146726a 100644
--- a/host/lib/utils/gain_group.cpp
+++ b/host/lib/utils/gain_group.cpp
@@ -63,7 +63,9 @@ public:
         /*NOP*/
     }
 
-    gain_range_t get_range(void){
+    gain_range_t get_range(const std::string &name){
+        if (not name.empty()) return _name_to_fcns[name].get_range();
+
         float overall_min = 0, overall_max = 0, overall_step = 0;
         BOOST_FOREACH(const gain_fcns_t &fcns, get_all_fcns()){
             const gain_range_t range = fcns.get_range();
@@ -76,7 +78,9 @@ public:
         return gain_range_t(overall_min, overall_max, overall_step);
     }
 
-    float get_value(void){
+    float get_value(const std::string &name){
+        if (not name.empty()) return _name_to_fcns[name].get_value();
+
         float overall_gain = 0;
         BOOST_FOREACH(const gain_fcns_t &fcns, get_all_fcns()){
             overall_gain += fcns.get_value();
@@ -84,7 +88,9 @@ public:
         return overall_gain;
     }
 
-    void set_value(float gain){
+    void set_value(float gain, const std::string &name){
+        if (not name.empty()) return _name_to_fcns[name].set_value(gain);
+
         std::vector<gain_fcns_t> all_fcns = get_all_fcns();
         if (all_fcns.size() == 0) return; //nothing to set!
 
@@ -140,10 +146,21 @@ public:
         }
     }
 
+    const std::vector<std::string> get_names(void){
+        return _name_to_fcns.keys();
+    }
+
     void register_fcns(
-        const gain_fcns_t &gain_fcns, size_t priority
+        const std::string &name,
+        const gain_fcns_t &gain_fcns,
+        size_t priority
     ){
+        if (name.empty() or _name_to_fcns.has_key(name)){
+            //ensure the name name is unique and non-empty
+            return register_fcns(name + "_", gain_fcns, priority);
+        }
         _registry[priority].push_back(gain_fcns);
+        _name_to_fcns[name] = gain_fcns;
     }
 
 private:
@@ -158,6 +175,7 @@ private:
     }
 
     uhd::dict<size_t, std::vector<gain_fcns_t> > _registry;
+    uhd::dict<std::string, gain_fcns_t> _name_to_fcns;
 };
 
 /***********************************************************************
diff --git a/host/lib/utils/thread_priority.cpp b/host/lib/utils/thread_priority.cpp
index c35e5fcb1..40b74f655 100644
--- a/host/lib/utils/thread_priority.cpp
+++ b/host/lib/utils/thread_priority.cpp
@@ -16,6 +16,8 @@
 //
 
 #include <uhd/utils/thread_priority.hpp>
+#include <uhd/utils/warning.hpp>
+#include <boost/format.hpp>
 #include <stdexcept>
 #include <iostream>
 
@@ -24,7 +26,12 @@ bool uhd::set_thread_priority_safe(float priority, bool realtime){
         set_thread_priority(priority, realtime);
         return true;
     }catch(const std::exception &e){
-        std::cerr << "set_thread_priority: " << e.what() << std::endl;
+        uhd::warning::post(str(boost::format(
+            "%s\n"
+            "Failed to set thread priority %d (%s):\n"
+            "Performance may be negatively affected.\n"
+            "See the general application notes.\n"
+        ) % e.what() % priority % (realtime?"realtime":"")));
         return false;
     }
 }
diff --git a/host/lib/utils/warning.cpp b/host/lib/utils/warning.cpp
index 8a7d35a23..05be7ae4d 100644
--- a/host/lib/utils/warning.cpp
+++ b/host/lib/utils/warning.cpp
@@ -17,16 +17,67 @@
 
 #include <uhd/utils/warning.hpp>
 #include <uhd/utils/algorithm.hpp>
+#include <uhd/utils/static.hpp>
+#include <uhd/types/dict.hpp>
 #include <boost/foreach.hpp>
+#include <sstream>
+#include <stdexcept>
 #include <iostream>
 #include <vector>
 
 using namespace uhd;
 
-void uhd::print_warning(const std::string &msg){
-    //print the warning message
-    std::cerr << std::endl << "Warning:" << std::endl;
+/***********************************************************************
+ * Registry implementation
+ **********************************************************************/
+//create the registry for the handlers
+typedef uhd::dict<std::string, warning::handler_t> registry_t;
+UHD_SINGLETON_FCN(registry_t, get_registry)
+
+//the default warning handler
+static void stderr_warning(const std::string &msg){
+    std::cerr << msg;
+}
+
+//register a default handler
+UHD_STATIC_BLOCK(warning_register_default){
+    warning::register_handler("default", &stderr_warning);
+}
+
+/***********************************************************************
+ * Post + format
+ **********************************************************************/
+void warning::post(const std::string &msg){
+    std::stringstream ss;
+
+    //format the warning message
+    ss << std::endl << "Warning:" << std::endl;
     BOOST_FOREACH(const std::string &line, std::split_string(msg, "\n")){
-        std::cerr << "    " << line << std::endl;
+        ss << "    " << line << std::endl;
+    }
+
+    //post the formatted message
+    BOOST_FOREACH(const std::string &name, get_registry().keys()){
+        get_registry()[name](ss.str());
     }
 }
+
+/***********************************************************************
+ * Registry accessor functions
+ **********************************************************************/
+void warning::register_handler(
+    const std::string &name, const handler_t &handler
+){
+    get_registry()[name] = handler;
+}
+
+warning::handler_t warning::unregister_handler(const std::string &name){
+    if (not get_registry().has_key(name)) throw std::runtime_error(
+        "The warning registry does not have a handler registered to " + name
+    );
+    return get_registry().pop(name);
+}
+
+const std::vector<std::string> warning::registry_names(void){
+    return get_registry().keys();
+}
diff --git a/host/lib/version.cpp b/host/lib/version.cpp
index 5edbca09b..93fdecb1a 100644
--- a/host/lib/version.cpp
+++ b/host/lib/version.cpp
@@ -21,3 +21,17 @@
 std::string uhd::get_version_string(void){
     return UHD_VERSION_STRING;
 }
+
+#include <uhd/utils/static.hpp>
+#include <boost/version.hpp>
+#include <iostream>
+
+UHD_STATIC_BLOCK(print_system_info){
+    std::cout
+        << BOOST_PLATFORM << "; "
+        << BOOST_COMPILER << "; "
+        << "Boost_" << BOOST_VERSION << "; "
+        << "UHD_" << uhd::get_version_string()
+        << std::endl << std::endl
+    ;
+}
diff --git a/host/test/CMakeLists.txt b/host/test/CMakeLists.txt
index 0d4607f68..2cc987f0c 100644
--- a/host/test/CMakeLists.txt
+++ b/host/test/CMakeLists.txt
@@ -18,8 +18,7 @@
 ########################################################################
 # unit test suite
 ########################################################################
-ADD_EXECUTABLE(main_test
-    main_test.cpp
+SET(test_sources
     addr_test.cpp
     buffer_test.cpp
     byteswap_test.cpp
@@ -28,13 +27,24 @@ ADD_EXECUTABLE(main_test
     error_test.cpp
     gain_group_test.cpp
     subdev_spec_test.cpp
+    time_spec_test.cpp
     tune_helper_test.cpp
     vrt_test.cpp
     warning_test.cpp
     wax_test.cpp
 )
-TARGET_LINK_LIBRARIES(main_test uhd)
-ADD_TEST(test main_test)
+
+#turn each test cpp file into an executable with an int main() function
+ADD_DEFINITIONS(-DBOOST_TEST_DYN_LINK -DBOOST_TEST_MAIN)
+
+#for each source: build an executable, register it as a test, and install
+FOREACH(test_source ${test_sources})
+    GET_FILENAME_COMPONENT(test_name ${test_source} NAME_WE)
+    ADD_EXECUTABLE(${test_name} ${test_source})
+    TARGET_LINK_LIBRARIES(${test_name} uhd)
+    ADD_TEST(${test_name} ${test_name})
+    INSTALL(TARGETS ${test_name} RUNTIME DESTINATION ${PKG_DATA_DIR}/tests)
+ENDFOREACH(test_source)
 
 ########################################################################
 # demo of a loadable module
@@ -42,6 +52,5 @@ ADD_TEST(test main_test)
 ADD_LIBRARY(module_test MODULE module_test.cpp)
 
 INSTALL(TARGETS
-   main_test
    RUNTIME DESTINATION ${PKG_DATA_DIR}/tests
 )
diff --git a/host/test/buffer_test.cpp b/host/test/buffer_test.cpp
index aadb3f951..8445412e7 100644
--- a/host/test/buffer_test.cpp
+++ b/host/test/buffer_test.cpp
@@ -23,7 +23,7 @@
 using namespace boost::assign;
 using namespace uhd::transport;
 
-static const boost::posix_time::milliseconds timeout(10);
+static const double timeout = 0.01/*secs*/;
 
 BOOST_AUTO_TEST_CASE(test_bounded_buffer_with_timed_wait){
     bounded_buffer<int>::sptr bb(bounded_buffer<int>::make(3));
diff --git a/host/test/gain_group_test.cpp b/host/test/gain_group_test.cpp
index 761372e5a..555ccaed3 100644
--- a/host/test/gain_group_test.cpp
+++ b/host/test/gain_group_test.cpp
@@ -81,12 +81,12 @@ static gain_group::sptr get_gain_group(size_t pri1 = 0, size_t pri2 = 0){
     gain_fcns.get_range = boost::bind(&gain_element1::get_range, &g1);
     gain_fcns.get_value = boost::bind(&gain_element1::get_value, &g1);
     gain_fcns.set_value = boost::bind(&gain_element1::set_value, &g1, _1);
-    gg->register_fcns(gain_fcns, pri1);
+    gg->register_fcns("g1", gain_fcns, pri1);
 
     gain_fcns.get_range = boost::bind(&gain_element2::get_range, &g2);
     gain_fcns.get_value = boost::bind(&gain_element2::get_value, &g2);
     gain_fcns.set_value = boost::bind(&gain_element2::set_value, &g2, _1);
-    gg->register_fcns(gain_fcns, pri2);
+    gg->register_fcns("g2", gain_fcns, pri2);
 
     return gg;
 }
diff --git a/host/test/main_test.cpp b/host/test/main_test.cpp
deleted file mode 100644
index 0b47303b7..000000000
--- a/host/test/main_test.cpp
+++ /dev/null
@@ -1,3 +0,0 @@
-#define BOOST_TEST_DYN_LINK
-#define BOOST_TEST_MAIN
-#include <boost/test/unit_test.hpp>
diff --git a/host/test/time_spec_test.cpp b/host/test/time_spec_test.cpp
new file mode 100644
index 000000000..5ad782160
--- /dev/null
+++ b/host/test/time_spec_test.cpp
@@ -0,0 +1,61 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <boost/test/unit_test.hpp>
+#include <uhd/types/time_spec.hpp>
+#include <boost/foreach.hpp>
+#include <iostream>
+
+BOOST_AUTO_TEST_CASE(test_time_spec_compare){
+    std::cout << "Testing time specification compare..." << std::endl;
+
+    BOOST_CHECK(uhd::time_spec_t(2.0) == uhd::time_spec_t(2.0));
+    BOOST_CHECK(uhd::time_spec_t(2.0) > uhd::time_spec_t(1.0));
+    BOOST_CHECK(uhd::time_spec_t(1.0) < uhd::time_spec_t(2.0));
+
+    BOOST_CHECK(uhd::time_spec_t(1.1) == uhd::time_spec_t(1.1));
+    BOOST_CHECK(uhd::time_spec_t(1.1) > uhd::time_spec_t(1.0));
+    BOOST_CHECK(uhd::time_spec_t(1.0) < uhd::time_spec_t(1.1));
+
+    BOOST_CHECK(uhd::time_spec_t(0.1) == uhd::time_spec_t(0.1));
+    BOOST_CHECK(uhd::time_spec_t(0.2) > uhd::time_spec_t(0.1));
+    BOOST_CHECK(uhd::time_spec_t(0.1) < uhd::time_spec_t(0.2));
+}
+
+#define CHECK_TS_EQUAL(lhs, rhs) \
+    BOOST_CHECK_CLOSE((lhs).get_real_secs(), (rhs).get_real_secs(), 0.001)
+
+BOOST_AUTO_TEST_CASE(test_time_spec_arithmetic){
+    std::cout << "Testing time specification arithmetic..." << std::endl;
+
+    CHECK_TS_EQUAL(uhd::time_spec_t(2.3) + uhd::time_spec_t(1.0), uhd::time_spec_t(3.3));
+    CHECK_TS_EQUAL(uhd::time_spec_t(2.3) - uhd::time_spec_t(1.0), uhd::time_spec_t(1.3));
+    CHECK_TS_EQUAL(uhd::time_spec_t(1.0) + uhd::time_spec_t(2.3), uhd::time_spec_t(3.3));
+    CHECK_TS_EQUAL(uhd::time_spec_t(1.0) - uhd::time_spec_t(2.3), uhd::time_spec_t(-1.3));
+}
+
+BOOST_AUTO_TEST_CASE(test_time_spec_parts){
+    std::cout << "Testing time specification parts..." << std::endl;
+
+    BOOST_CHECK_EQUAL(uhd::time_spec_t(1.1).get_full_secs(), 1);
+    BOOST_CHECK_CLOSE(uhd::time_spec_t(1.1).get_frac_secs(), 0.1, 0.001);
+    BOOST_CHECK_EQUAL(uhd::time_spec_t(1.1).get_tick_count(100), 10);
+
+    BOOST_CHECK_EQUAL(uhd::time_spec_t(-1.1).get_full_secs(), -1);
+    BOOST_CHECK_CLOSE(uhd::time_spec_t(-1.1).get_frac_secs(), -0.1, 0.001);
+    BOOST_CHECK_EQUAL(uhd::time_spec_t(-1.1).get_tick_count(100), -10);
+}
diff --git a/host/test/tune_helper_test.cpp b/host/test/tune_helper_test.cpp
index 1ef4af330..e0500ae3f 100644
--- a/host/test/tune_helper_test.cpp
+++ b/host/test/tune_helper_test.cpp
@@ -91,6 +91,44 @@ private:
     }
 };
 
+class dummy_subdev_bw : public wax::obj{
+private:
+    void get(const wax::obj &key, wax::obj &val){
+        switch(key.as<subdev_prop_t>()){
+
+        case SUBDEV_PROP_FREQ:
+            val = _freq;
+            return;
+
+        case SUBDEV_PROP_USE_LO_OFFSET:
+            val = true;
+            return;
+
+        case SUBDEV_PROP_BANDWIDTH:
+            val = _bandwidth;
+            return;
+
+        default: UHD_THROW_PROP_GET_ERROR();
+        }
+    }
+
+    void set(const wax::obj &key, const wax::obj &val){
+        switch(key.as<subdev_prop_t>()){
+        case SUBDEV_PROP_FREQ:
+            _freq = val.as<double>();
+            return;
+
+        case SUBDEV_PROP_BANDWIDTH:
+            _bandwidth = val.as<double>();
+            return;
+
+        default: UHD_THROW_PROP_SET_ERROR();
+        }
+    }
+
+    double _freq, _bandwidth;
+};
+
 class dummy_dsp : public wax::obj{
 public:
     dummy_dsp(double codec_rate):
@@ -106,6 +144,10 @@ private:
             val = _codec_rate;
             return;
 
+        case DSP_PROP_HOST_RATE:
+            val = _host_rate;
+            return;
+
         case DSP_PROP_FREQ_SHIFT:
             val = _freq_shift;
             return;
@@ -125,11 +167,15 @@ private:
             _freq_shift = val.as<double>();
             return;
 
+        case DSP_PROP_HOST_RATE:
+            _host_rate = val.as<double>();
+            return;
+
         default: UHD_THROW_PROP_SET_ERROR();
         }
     }
 
-    double _codec_rate, _freq_shift;
+    double _codec_rate, _freq_shift, _host_rate;
 };
 
 /***********************************************************************
@@ -141,7 +187,7 @@ BOOST_AUTO_TEST_CASE(test_tune_helper_rx){
     dummy_subdev subdev(1e6);
     dummy_dsp dsp(100e6);
 
-    std::cout << "Testing tune helper RX automatic LO offset" << std::endl;
+    std::cout << "Testing tune helper RX automatic IF offset" << std::endl;
     tune_result_t tr = tune_rx_subdev_and_dsp(subdev.get_link(), dsp.get_link(), 0, 2.3451e9);
     std::cout << tr.to_pp_string() << std::endl;
     BOOST_CHECK_CLOSE(tr.actual_inter_freq, 2.345e9, tolerance);
@@ -155,7 +201,7 @@ BOOST_AUTO_TEST_CASE(test_tune_helper_tx){
     dummy_subdev subdev(1e6);
     dummy_dsp dsp(100e6);
 
-    std::cout << "Testing tune helper TX automatic LO offset" << std::endl;
+    std::cout << "Testing tune helper TX automatic IF offset" << std::endl;
     tune_result_t tr = tune_tx_subdev_and_dsp(subdev.get_link(), dsp.get_link(), 0, 2.3451e9);
     std::cout << tr.to_pp_string() << std::endl;
     BOOST_CHECK_CLOSE(tr.actual_inter_freq, 2.345e9, tolerance);
@@ -178,3 +224,30 @@ BOOST_AUTO_TEST_CASE(test_tune_helper_rx_nyquist){
     double freq_derived = derive_freq_from_rx_subdev_and_dsp(subdev.get_link(), dsp.get_link(), 0);
     BOOST_CHECK_CLOSE(freq_derived, -45e6, tolerance);
 }
+
+BOOST_AUTO_TEST_CASE(test_tune_helper_rx_lo_off){
+    dummy_subdev_bw subdev;
+    dummy_dsp dsp(100e6);
+    tune_result_t tr;
+
+    std::cout << "Testing tune helper RX automatic LO offset B >> fs" << std::endl;
+    subdev[SUBDEV_PROP_BANDWIDTH] = double(40e6);
+    dsp[DSP_PROP_HOST_RATE] = double(4e6);
+    tr = tune_rx_subdev_and_dsp(subdev.get_link(), dsp.get_link(), 0, 2.45e9);
+    std::cout << tr.to_pp_string() << std::endl;
+    BOOST_CHECK_CLOSE(tr.actual_inter_freq, 2.45e9+4e6/2, tolerance);
+
+    std::cout << "Testing tune helper RX automatic LO offset B > fs" << std::endl;
+    subdev[SUBDEV_PROP_BANDWIDTH] = double(40e6);
+    dsp[DSP_PROP_HOST_RATE] = double(25e6);
+    tr = tune_rx_subdev_and_dsp(subdev.get_link(), dsp.get_link(), 0, 2.45e9);
+    std::cout << tr.to_pp_string() << std::endl;
+    BOOST_CHECK_CLOSE(tr.actual_inter_freq, 2.45e9+(40e6-25e6)/2, tolerance);
+
+    std::cout << "Testing tune helper RX automatic LO offset B < fs" << std::endl;
+    subdev[SUBDEV_PROP_BANDWIDTH] = double(20e6);
+    dsp[DSP_PROP_HOST_RATE] = double(25e6);
+    tr = tune_rx_subdev_and_dsp(subdev.get_link(), dsp.get_link(), 0, 2.45e9);
+    std::cout << tr.to_pp_string() << std::endl;
+    BOOST_CHECK_CLOSE(tr.actual_inter_freq, 2.45e9, tolerance);
+}
diff --git a/host/test/warning_test.cpp b/host/test/warning_test.cpp
index 6202c4270..db19955de 100644
--- a/host/test/warning_test.cpp
+++ b/host/test/warning_test.cpp
@@ -19,9 +19,9 @@
 #include <uhd/utils/warning.hpp>
 #include <iostream>
 
-BOOST_AUTO_TEST_CASE(test_print_warning){
+BOOST_AUTO_TEST_CASE(test_warning_post){
     std::cerr << "---begin print test ---" << std::endl;
-    uhd::print_warning(
+    uhd::warning::post(
         "This is a test print for a warning message.\n"
         "And this is the second line of the test print.\n"
     );
diff --git a/host/utils/usrp-e-loopback.c b/host/utils/usrp-e-loopback.c
index f400fe0be..454d81ba7 100644
--- a/host/utils/usrp-e-loopback.c
+++ b/host/utils/usrp-e-loopback.c
@@ -8,7 +8,7 @@
 #include <sys/mman.h>
 #include <linux/usrp_e.h>
 
-// max length #define PKT_DATA_LENGTH 1016
+#define MAX_PACKET_SIZE 1016
 static int packet_data_length;
 static int error;
 
@@ -19,6 +19,30 @@ struct pkt {
 	short data[];
 };
 
+static int length_array[2048];
+static int length_array_tail = 0;
+static int length_array_head = 0;
+
+pthread_mutex_t length_array_mutex; //gotta lock the index to keep it from getting hosed
+
+//yes this is a circular buffer that does not check empty
+//no i don't want to hear about it
+void push_length_array(int length) {
+	pthread_mutex_lock(&length_array_mutex);
+	if(length_array_tail > 2047) length_array_tail = 0;
+	length_array[length_array_tail++] = length;
+	pthread_mutex_unlock(&length_array_mutex);
+}
+
+int pop_length_array(void) {
+	int retval;
+	pthread_mutex_lock(&length_array_mutex);
+	if(length_array_head > 2047) length_array_head = 0;
+	retval = length_array[length_array_head++];
+	pthread_mutex_unlock(&length_array_mutex);
+	return retval;
+}
+
 static int fp;
 
 static int calc_checksum(struct pkt *p)
@@ -29,10 +53,10 @@ static int calc_checksum(struct pkt *p)
 	sum = 0;
 
 	for (i=0; i < p->len; i++)
-		sum += p->data[i];
+		sum ^= p->data[i];
 
-	sum += p->seq_num;
-	sum += p->len;
+	sum ^= p->seq_num;
+	sum ^= p->len;
 
 	return sum;
 }
@@ -44,6 +68,7 @@ static void *read_thread(void *threadid)
 	struct pkt *p;
 	unsigned long bytes_transfered, elapsed_seconds;
 	struct timeval start_time, finish_time;
+	int expected_count;
 
 	printf("Greetings from the reading thread!\n");
 
@@ -78,6 +103,11 @@ static void *read_thread(void *threadid)
 				error = 1;
 		}
 
+		expected_count = pop_length_array()*2+12;
+		if(cnt != expected_count) {
+			printf("Received %d bytes, expected %d\n", cnt, expected_count);
+		}
+
 		prev_seq_num = p->seq_num;
 
 		if (calc_checksum(p) != p->checksum) {
@@ -131,7 +161,9 @@ static void *write_thread(void *threadid)
 		if (packet_data_length > 0)
 			p->len = packet_data_length;
 		else
-			p->len = (random() & 0x1ff) + (1004 - 512);
+			p->len = (random()<<1 & 0x1ff) + (1004 - 512);
+
+		push_length_array(p->len);
 
 		p->checksum = calc_checksum(p);
 
@@ -146,6 +178,7 @@ static void *write_thread(void *threadid)
 int main(int argc, char *argv[])
 {
 	pthread_t tx, rx;
+	pthread_mutex_init(&length_array_mutex, 0);
 	long int t;
 	struct sched_param s = {
 		.sched_priority = 1
@@ -159,6 +192,10 @@ int main(int argc, char *argv[])
 	}
 
 	packet_data_length = atoi(argv[1]);
+	if(packet_data_length > MAX_PACKET_SIZE) {
+		printf("Packet size must be smaller than %i\n", MAX_PACKET_SIZE);
+		exit(-1);
+	}
 
 	fp = open("/dev/usrp_e0", O_RDWR);
 	printf("fp = %d\n", fp);