Trasmettere via software: EBU/CRC mostrano come fare

EBU Technical Review descrive in un suo contributo sul numero di settembre le demo di radio "ibrida" messe in scena al recente salone IBC di Amsterdam. Nella postazione coordinata da Mathias Coinchon è stato dimostrato come grazie a implementazioni software open source sia possibile allestire con pochi investimenti trasmissioni miste analogico-digitali, con diversi sistemi (FM-RDS, DAB, DRM), utilizzando tecniche di modulazione completamente software. Un altro test molto interessante riguarda il sistema RadioDNS, che sfrutta i metadati integrabili (per esempio via RDS) nelle modulazioni analogiche, così come in quelle digitali per stabilire una connessione diretta tra contenuti radiotrasmessi e contenuti Web.

Per questa dimostrazione, in particolare la parte riguardante la trasmissione software defined, l'EBU ha sfruttato il software raccolto negli mmbTools, un bellissimo progetto realizzato dal Communications Research Centre del Canada. Il sito degli mmbTools mette a disposizione attraverso un LiveCD gli strumenti per "modulare" via software trasmissioni a standard analogico, inclusa appunto l'FM-RDS e digitale T-DMB. La piattaforma utilizzata per le trasmissioni sperimentali DRM all'IBC è la tedesca Spark.

RadioDNS opens up the radio

27 September 2010

At the IBC, a team of EBU radio engineers integrated a full radio chain, from studio to consumer receivers, to demonstrate analogue and digital radio broadcasts with multimedia enhancements. What was the background of this demonstration?

Open software defined radio transmission platform

"First of all we wanted to show how technology is evolving and that it is now possible to create radio broadcasts for virtually any platform (DAB, DAB+, DRM, FM and streaming) with a common, cost-efficient software defined radio platform. That is exactly what we did: we broadcast on all of these platforms at the IBC, using 1 rack of almost of-the-shelf components, all this for less than €5,000. DAB/DAB+ encoding/multiplexing/modulation was performed using MMBTools from CRC. DRM transmission used Spark software while FM was implemented using gnuradio. The RF transmission was then produced by USRP Universal Software Radio Platform. "We hope to trigger radio people that they can try out new things without having to set up an expensive infrastructure", explains Mathias Coinchon (EBU).

Multimedia enhancements of hybrid radio

But the demo was not about the platform only, it also emphasised the developments happening 'around' the radio with the hybrid broadcast/Internet approach, such as RadioDNS and RadioVIS. Specifications which allow radios to seamlessly find additional internet-based content to, for example, show an album picture, do an audience poll or provide extensive EPG information. At the IBC, EBU in partnership with CRC and Global labs showed the RadioDNS system work on various different devices and plaftorms using DAB/DAB+ or FM.

For more information on EBU TECHNICAL's radio work, see the radio section on tech.ebu.ch.

Openmokast and mmbTools at IBC 2010

The Communications Research Centre Canada (CRC) was invited by the European Broadcasting Union to demonstrate CRC's mmbTools open platforms for mobile broadcasting at IBC 2010. These demonstrations will be part EBU's exhibit on "Hybrid Radio" in Hall 10, Booth 10.D21.

In the logical continuity of our CRC mmbTools and Openmokast works for DAB/DMB, we have integrated and developed new approaches and tools to foster the development of innovative hybrid FM-RDS Internet radio applications and services. Here is a list of CRC contributions for this event:

• CRC mmbTools software (DAB+ audio encoder, multiplexer and mobulator) fo the live on-site 10 Watts DAB transmission
• DAB to Wifi "repeater" running on the OMAP-based IGEPv2 hardware platform.
• Real-time FM and RDS software modulators based on GNU Radio and the universal software defined radio platform USRP
• Real-time FM and RDS reception on the USRP with GNU Radio RDS monitoring
• CRC's Open source RDS decoding software library
• CRC mmbTools Live CD which now includes all our FM-RDS tools in addition to our DAB tools
• Demonstration of DAB and FM-RDS on various Android Smartphones: G1, Nexus One, SE Xperia x10 mini,
• New release of the CRC FM Radio Player App on the Android Market. This demo shows how an FM App could work on Android if FM APIs were available to 3rd party developers. This App cannot receive FM audio on Android but it receives and decodes real-time RDS arriving from a wifi connection. An RDS server is required to stream RDS over wifi. The App decodes some ODA data like phone numbers and http links.
• Demonstration of CRC's “CELT over DAB” application. CELT is a royalty-free audio codec developed by the Xiph.Org foundation.


Contact: François Lefebvre
Email: francois (dot) lefebvre (at) crc (dot) gc (dot) ca

Twitter: http://twitter.com/fralef


Our channel on Youtube: http://www.youtube.com/crcmmb 


Our presentations on Slideshare: http://www.slideshare.net/tag/crcmmb


Personal blog: http://www.broadcasting20.org




For technical details, online and off-line tools, source code and downloads please visit our projects websites:

http://mmbtools.crc.gc.ca


http://www.openmokast.org