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diff --git a/introduction.tex b/introduction.tex index 216bb96..8db20cd 100644 --- a/introduction.tex +++ b/introduction.tex @@ -1,7 +1,12 @@ +\section{Introduction} +This is the official documentation for the \mmbtools. These tools can be used to +experiment, learn and setup a DAB and \dabplus transmitter. + \section{Purpose} The different programs that are part of the \mmbtools each have their own documentation regarding command-line options and configuration settings, and the -opendigitalradio.org wiki contains many explanations and pointers, but there is +opendigitalradio.org wiki\footnoteurl{http://opendigitalradio.org} +contains many explanations and pointers, but there is no single source of documentation available for the whole tool-set. This document aims to solve this, by first outlining general concepts, @@ -9,6 +14,64 @@ presenting different usage scenarios and detailing a complete transmission setup. With this document in hand, you should be able to understand all elements -composing a \mmbtools transmission chain. +composing a \mmbtools transmission chain, and how to set one up. + +\section{Presentation of the Tools} +\subsection{Origins} +In 2002, Communications Research Centre Canada\footnoteurl{http://crc.ca} +started developing a DAB multiplexer. This effort evolved through the years, and +was published later\sidenote{when?} as \mbox{CRC-DabMux} under the GPL +open-source licence. + +CRC also developed a DAB modulator, called \mbox{CRC-DABMOD}, which could create +baseband I/Q samples from an ETI file. This I/Q data could then be set to +a hardware device using another tool. For the Ettus USRPs, a ``wave player'' +script was necessary to interface to GNURadio. Only DAB Transmission Mode 2 was +supported. \mbox{CRC-DABMOD} was also released under the GPL\sidenote{when?}. + +As encoders, toolame could be used for DAB, and CRC developed a closed-source +\mbox{CRC-DABPLUS} \dabplus encoder. + +These three CRC-~tools, and some additional services available on the now +unreachable website\footnote{There are some snapshots of the website available + on \url{http://archive.org}.} \url{http://mmbtools.crc.ca} were +part of the \mbox{CRC-mmbTools}. These tools made it possible to set up the +first DAB transmission experiments. + +In 2012, these tools received experimental support for single-frequency +networks, a functionality that has been developed by Matthias P. Braendli during +his Master's thesis\footnote{The corresponding report is available at + \url{http://mpb.li/report.pdf}}. +Because SFNs only make sense in TM 1, CRC subsequently released a patch to +\mbox{CRC-DABMOD} that enabled all four transmission modes. + +At that point, involvement from CRC started to decline. The SFN patch was +finally never included in the \mbox{CRC-mmbTools}, and as time passed by, the +de-facto fork on \url{http://mpb.li} was receiving more and more features. +Having two different programs with the same name made things complicated, and +the tools were officially forked with the approval of CRC in Feb 2014, and given +the new name \mbox{ODR-mmbTools}. They are now developed by the Opendigitalradio +association. + +In April 2014, the official \mbox{CRC-mmbTools} website went offline, and it has +become very difficult, if not impossible to acquire licences for the +\mbox{CRC-DABPLUS} encoder. Luckily there is an open-source replacement +available, which was part of Google's Android sources. This encoder has been +extended with the necessary \dabplus{}-specific requirements (960-transform, +error correction, framing, etc.), and now exists under the name +\mbox{fdk-aac-dabplus}. + +\subsection{Included Tools} +The \mmbtools contain the tools \mbox{ODR-DabMux}, \mbox{ODR-DabMod}, +\mbox{toolame-dab}, \mbox{fdk-aac-dabplus}, and other scripts, bits and pieces +that are useful for the setup of a transmission chain. + +\subsubsection{ODR-DabMux} +\subsubsection{ODR-DabMod} +\subsubsection{toolame-dab} +\subsubsection{fdk-aac-dabplus} +\subsubsection{mmbtools-aux} + + % vim: spl=en spell tw=80 et |