Mathias Coinchon, Senior Project Manager, Technology & Innovation, European Broadcasting Union and WorldDMB Technical Committee, Vice-Chairman
A decade ago, DAB was perceived by most local and community stations as an expensive transmission method unsuitable for them, with no future and locked by big broadcasters and operators. Since then, opportunities for these stations to broadcast on DAB have become accessible in Switzerland and regular transmissions have started over Geneva in May 2014 and in Zurich in September 2014.
In technology terms, in order to reduce costs, the infrastructure is simplified to the maximum by using single transmission site with all the encoding/multiplexing/modulation happening on a PC and using Internet streams from radio stations as the audio source. Of course the service level is not the same as with a regular operator but is generally acceptable for non-commercial radio stations. The other element is the use of the mmbtools free open source software solution developed by CRC in Canada and now maintained by the opendigitalradio.org community since CRC dropped the project. Free is not as in free beer but free speech meaning competences are required to integrate such a solution that is not turnkey. Many non-commercial radio stations don’t have money but can find passionate people that can grow such a competence to make an integration and that will contribute to make the software better by reporting bugs or sometimes modify source code. All the source code is public and can be found on the Opendigitalradio software repository.
In content terms, there are small FM stations but the most interested are the local web radio stations or new projects generally from young radio people that don’t have access to FM. Many of these projects are self-funded and may disappear in the future but they are like radio startups and contribute to make digital radio more attractive and bring young talents to radio.
Apart from Switzerland, similar developments are taking place in Europe. Kanaplus in Denmark is operating a local DAB multiplex near Copenhagen since 2012, or Société de Diffusion Numérique (SDN) in Marseilles, being amongst the first operators of regular DAB+ transmissions in France. OFCOM in the UK is in contact with the community and has also conducted tests in Brighton using the same software and is currently making further tests with local radio stations. We can also note that local tests are happening with traditional equipment in other countries.
New developments on the software are underway to add SFN feature, remote encoders running on low cost embedded PC similar to the Raspberry Pi, Slideshow. Tests are also being done using the software multiplexer on professional transmitters from GatesAir, the efficiency gain could mean less operating costs and compensate the higher investment costs.
As one of the DAB dinosaur was saying one day, “Digital Radio will have succeeded the day we will see pirate DAB stations”, this prediction may not be so far away but hopefully with stations that won’t need to be pirate.