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| − | __NOTOC__ | + | __NOTOC__ __NOEDITSECTION__ |
| | + | <div style="font-size:282%">Opendigitalradio.org</div> |
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| − | <div style="font-size:282%"> Opendigitalradio.org </div>
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| − | <br>
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| − | <big> <b>Open and easy digital broadcasting techniques based on software radio - because digital radio transmission and development must also become democratized. </b></big> | + | <P> |
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| − | Broadcasting is sometime considered, by the new generations, as a dying media that will be soon completely superseeded by Internet. However it is a nice, efficient and green way to reach masses without intermediaries but just using radio spectrum directly (despite the fact that the use spectrum is subject to licence). For these reasons and apart from the big public or private broadcasters interests, it has still an interest for local communities. In particular, it offers anonymous listening and is free-to-air (no subscription needed) which is of importance in poor countries or where freedom of information does not apply. | + | <BIG> |
| | + | Open techniques for Digital Radio Broadcasting |
| | + | </BIG> |
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| − | In radio, Analog transmission using AM, FM is still very popular but may be replaced in the future by digital techniques such as [http://www.worlddab.org/introduction_to_digital_broadcasting/dab_digital_radio DAB], [http://www.worlddab.org/introduction_to_digital_broadcasting/dab_plus_digital_radio DAB+], [http://www.worlddab.org/introduction_to_digital_broadcasting/dmb_-_mobile_television T-DMB], [http://www.drm.org/drm-the-system/technical-aspects/ DRM30] (Digital Radio Mondiale) or [http://www.drm.org/drm-the-system/drm/ DRM+] (for digitalisation of FM band).
| + | {| style="width:100%; border-spacing:8px; margin:-8px -8px;" |
| − | In television, analog transmission using PAL or SECAM is being stopped in Europe and replaced by DVB-T, DVB-T2, DVB-H (for mobile) or other digital satellite or cable transmission techniques.
| + | |class="MainPageBG" style="width:100%; border:1px solid #ddcef2; background:#faf5ff; vertical-align:top; color:#000;"| |
| | + | {| cellpadding="2" cellspacing="5" style="width:100%; vertical-align:top; background:#faf5ff; color:#000" |
| | + | ! <h2 style="margin:0; background:#ddcef2; font-size:120%; font-weight:bold; border:1px solid #afa3bf; text-align:left; color:#000; padding:0.2em 0.4em;">Background</h2> |
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| | + | Open digital broadcasting techniques based on software defined radio. Digital radio transmission and development must also become democratized for experimenters and small broadcasters. Opendigitalradio.org wiki is about creating a community for documenting and exchanging experimentations and gather information about existing small-scale DAB projects. Please read [[Introduction]] for more information. |
| | + | '''[[Association Opendigitalradio|Opendigitalradio is a non-profit association based in Switzerland]]''' (page in french), offering also a broadcast infrastructure for temporary radio stations. |
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| − | Transmitting using these technologies usually requires complex and costly equipment out of reach of individuals. However, since the democratization of software defined radio (SDR), a new field of possibilities opens for experimentation, micro networks, etc. In the longer term also if software based radio become also democratized in common receivers, it could even be possible to develop personalized broadccasting system based on free/open technologies for example. The combination of personal (Internet,..) networks and broadcast also offer interesting possibilities (see [http://www.imdalliance.org/ IMDA] and [http://www.radiodns.org/ RadioDNS]).
| + | This wiki is also the home of the '''ODR-mmbTools''', the continuation of the CRC-mmbTools from [http://mmbtools.crc.ca CRC]. Please see [[Introduction on DAB/DAB+]] |
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| − | So this website will focus on tips, tricks and techniques to produce and receive digital broadcast signals. Most of the content is based on development from research centers, groups or individuals that did the "real work". The objective of this website is to follow developments, integrate them and show applications.
| + | Have a look at the [http://opendigitalradio.github.io/mmbtools-doc/mmbtools.pdf guide] |
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| − | ==NEWS==
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| − | *<BIG>'''CRC just announced the release of the source code (GPL) of their software DAB OFDM modulator'''</BIG> http://www.slideshare.net/fralef/update-on-crc-open-and-free-dab-tools
| + | [[News|Older news]] |
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| | + | |} |
| | + | |} |
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| | + | {| style="width:100%; border-spacing:8px; margin:-8px -8px;" |
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| | + | {| cellpadding="2" cellspacing="5" style="width:100%; vertical-align:top; background:#f5fffa; color:#000" |
| | + | ! <h2 style="margin:0; background:#cef2e0; font-size:120%; font-weight:bold; border:1px solid #afa3bf; text-align:left; color:#000; padding:0.2em 0.4em;">DAB/DAB+ transmission</h2> |
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| | + | [[Image:Logo mmb.png|right]] |
| | + | *[[Introduction on DAB/DAB+]] |
| | + | *[[DAB/DAB+ encoding]]: MPEG Layer II or HE-AAC encoding, slideshow encoding |
| | + | *[[DAB multiplexing]]: putting together DAB/DAB+/DMB programs |
| | + | *[[DAB modulation]]: create the baseband COFDM modulation |
| | + | *[[DAB hardware]]: software radio peripheral, filtering, amplification |
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| | + | |} |
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| − | *<big>'''Register to the [https://lists.saitis.net/cgi-bin/mailman/listinfo/openradio mailing list]'''</big> to get informed, involved or for any questions.
| + | {| cellpadding="2" cellspacing="5" style="width:100%; vertical-align:top; background:#f5fffa; color:#000" |
| − | *[http://events.ccc.de/congress/2009/wiki/Radio_broadcasting CCC Workshop] on digital radio and software radio.
| + | ! <h2 style="margin:0; background:#cef2e0; font-size:120%; font-weight:bold; border:1px solid #afa3bf; text-align:left; color:#000; padding:0.2em 0.4em;">Real cases, examples</h2> |
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| − | ==DAB, DAB+ and T-DMB transmission==
| + | The ODR-mmbTools are used in several real-world 24/7 broadcasts, as shown on http://www.opendigitalradio.org/software |
| − | [[Image:dab1.jpg|thumbnail|Home setup]]
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| − | DAB, DAB+ and T-DMB European digital radio and mobile television standards share the same transmission system. It based on [http://en.wikipedia.org/wiki/Orthogonal_frequency-division_multiplexing OFDM] modulation and use 1.5MHz of spectrum in VHF television band 3 (or L-band in SHF). A transmitter is broadcasting a set of programs, called a multiplex. The system has been designed for mobile use and is robust up to 300km/h.
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| − | With the development of '''[http://mmbtools.crc.ca MMBTools set made by CRC]''', it is now possible to run a full transmission infrastructure on a laptop running linux and using a [http://en.wikipedia.org/wiki/USRP USRP] as [[RF]] hardware (with [[wikipedia:gnuradio|gnuradio]]) or any other similar device.
| + | A recipe for a low cost DAB transmission chain for local broadcasts based on the ODR-mmbTools is the [[RaspDAB]] description. |
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| − | The transmission chain can be divided in 4:
| + | Older presentations: |
| − | *The encoding: encoding the sound to [[wikipedia:MPEG-1 Audio Layer II|MPEG-2 Layer II]] for DAB, [[wikipedia:High-Efficiency Advanced Audio Coding|MPEG-4 HE-AACv2]] for DAB+ or video in MPEG-4 H.264 for T-DMB. | + | *[http://www.slideshare.net/radioradioradio/local-dab-broadcasting Presentation] and [[WorldDMB GA 2010 Open DAB demonstration|demonstration]] of the full open source DAB transmission solution at 2010 WorldDMB General Assembly in Belfast |
| − | *The Multiplexer: gather different streams, produce necessary signalling and output a single 2Mbit/s stream in ETI format (Ensemble Transport Interface) | + | *[[First licensed open dab transmission]] for Label Suisse Festival 17-19 September 2010 Lausanne. |
| − | *The Modulator: take the ETI stream and produce the complex [[wikipedia:baseband|baseband]] OFDM signal ready for upconvert at the desired radio frequency. | + | *[[Demonstration of open source digital transmission chain at IBC]], Stand 10.D21 (EBU), 10-14 September 2010 |
| − | *The [[RF]] transmission performed by the USRP using appropriate RF daughterboards (Basic TX or modified RFX400). | + | *[[DAB scripts examples]] |
| | + | *[[Installer scripts]] for '''Debian''' |
| | + | *[[How to configure SPI (Service and Programme Information) for ODR-DabMux]] |
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| | + | |} |
| | + | |} |
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| − | [[CRC]] has recently opened the source code of the multiplexer. However as the modulator depends on other developments, it is free but not opened. The MPEG-4 AAC encoding is subject to royalty payment and so CRC is selling it. | + | {| style="width:100%; border-spacing:8px; margin:-8px -8px;" |
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| | + | {| cellpadding="2" cellspacing="5" style="width:100%; vertical-align:top; background:#fffaf5; color:#000" |
| | + | ! <h2 style="margin:0; background:#f2e0ce; font-size:120%; font-weight:bold; border:1px solid #afa3bf; text-align:left; color:#000; padding:0.2em 0.4em;">Other digital systems, transmission and reception</h2> |
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| | + | *[[DAB reception]] (Openmokast and others) |
| | + | *[[DAB measurement]] (measurement&monitoring tools, planning tools). |
| | + | *[[DRM/DRM+ Digital Radio Mondiale]], digital radio system for AM bands (LW, MW and SW) and all VHF bands (FM band and others). |
| | + | *[[FM RDS transmission]] (not really a digital system except RDS ;) |
| | + | *[[Crazy techniques using a VGA card as radio peripheral]] |
| | + | *[[Coverage planning]] |
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| | + | |} |
| | + | |} |
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| − | However thank to the modular approach from these tools it is possible to interface it with other implementations. If there's no other software OFDM DAB modulator implementation at the moment, for the encoding it is possible to re-use [[wikipedia:TooLame|TooLame]] that is an implementation of MPEG-2 Layer II. Using another software modulator is also possible (gnuradio based ?).
| + | {| style="width:100%; border-spacing:8px; margin:-8px -8px;" |
| | + | |class="MainPageBG" style="width:100%; border:1px solid #cedff2; background:#f5faff; vertical-align:top; color:#000;"| |
| | + | {| cellpadding="2" cellspacing="5" style="width:100%; vertical-align:top; background:#f5faff; color:#000" |
| | + | ! <h2 style="margin:0; background:#cedff2; font-size:120%; font-weight:bold; border:1px solid #afa3bf; text-align:left; color:#000; padding:0.2em 0.4em;">Contacts</h2> |
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| | + | Please follow the odr-mmbtools discussion on groups.io for bug reports, solutions and updates. See the webiste https://groups.io/g/odr-mmbtools how to subscribe. This is the follow up of the crc-mmbtools mailing list on googlegroups (https://groups.google.com/g/crc-mmbtools) , which is still available to check for solutions to older problems. |
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| − | ===Software===
| + | Follow us on '''Twitter''': http://twitter.com/opendigiradio to get informed, involved or for any questions. Find us [http://www.facebook.com/opendigitalradio also on '''Facebook'''] |
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| − | *[[Example of live re-transmission on DAB of an Internet Radio radio station]]
| + | Email: broadcast at opendigitalradio.org |
| − | *'''[[Example of live re-broadcasting on DAB of many Internet radio stations]]'''
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| − | *[[Example of the creation of a multiplex stream of 2 DAB stations]]
| + | |} |
| − | *[[Example of the creation of a DAB+ transmission]]
| + | |} |
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| − | Info pages on tools
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| − | *[[CRC-DabMux]] DAB/DAB+/T-DMB multiplexer
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| − | *[[CRC-DabMod]] DAB modulator
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| − | *[[CRC-Dwap.py]] USRP modulator and controller
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| − | *[[toolame]] MPEG-Layer II encoder
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| − | [[Image:dab_s_1.jpg |thumbnail|right| USRP]]
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| − | All questions and enquiries on MMBtools should be done directly on [http://mmbtools.crc.ca/component/option,com_fireboard/Itemid,55/ their forum]
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| − | ===Hardware===
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| − | Find in this section some hardware experiment done with USRP RF front end like daughterboards or external devices (filters, power amplifiers).
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| − | The following Ettus daughterboards can be used for transmission in [[Band 3 Channels|VHF band III]]:
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| − | [[Basic TX]], [[RFX400 daughterboard modification|RFX400]] (after modification) or the new [[WBX]] board.
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| − | *[[Example of RF amplifier for DAB]] for VHF band III (never connect to an antenna without a license !)
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| − | *[[RFX400 daughterboard modification]] to operate in VHF Band III (around 200MHz)
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| − | <br>
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| − | <br>
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| − | ==FM/RDS==
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| − | Despite the fact that FM is an analog technology, it is possible to generate it using software defined radio with enhanced possibilities such as simultaneous transmission of many FM stations.
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| − | *[[Simple FM transmitter using gnuradio]]
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| − | *[[Stereo FM transmitter using gnuradio]]
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| − | *[[FM transmission on many channels using gnuradio]]
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| − | *[[Multiple stations FM transmitter using gnuradio]]
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| − | *[https://128.2.212.19/wiki/RDS RDS on gnuradio]
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| − | ==Open DAB/DAB+/T-DMB software receiver==
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| − | [[Image:Phon3b small.jpg|100px|right]]
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| − | ===Software defined DAB receiver (up to logical layer)===
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| − | *[[Gnuradio DAB constellation using gr-dab and USRP]]
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| − | *[http://people.ee.ethz.ch/~andrmuel/files/gnuradio/ Gnuradio blocks for DAB reception] (developments from Andreas Mueller, ETHZ)
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| − | ===Openmokast ===
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| − | Software defined DAB receiver (from logical layer up to application layer).
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| − | Open Receiver project from CRC using RDI streams from DAB baseband receivers/decoders.
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| − | *http://www.openmokast.org
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| − | ==Digital Radio Mondiale (DRM30, DRM+)==
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| − | [[Image:drm4.jpg |thumbnail | right | RX DRM ]]
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| − | Under construction
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| − | [http://sourceforge.net/apps/mediawiki/drm/index.php?title=Main_Page Dream] open software receiver and transmitter
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| − | [http://www.drm-sender.de/ Spark] free DRM/DRM+ transmitter
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| − | <br>
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| − | <br>
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| − | ==Other crazy techniques==
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| − | Under construction...
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| − | Transmission using a VGA card D/A converter as transmitter !
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| − | *DVB-T transmission (static signal): http://bellard.org/dvbt/
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| − | *Live FM transmitter : http://bk.gnarf.org/creativity/vgasig/
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