The German Digital Radio Mondiale Forum, an affiliate organization of the Digital Radio Mondiale Consortium, has published an overview on the digital terrestrial technologies available in Europe and the suitability of each technology for the German market.
The report outlines the reasons for digitization, and the advantages and disadvantages of the DAB, DAB+ and DRM (DRM30, DRM+) systems when applied to specific broadcaster requirements in Germany. It finds that DAB is the most efficient when covering large areas with up to 16 to 20 simultaneous programs multiplexed on the same frequency, whereas DRM+ can be equally efficient for the distribution of just one or a few programs covering a small area with a single transmitter.
It explains that DAB/DAB+ and DRM+ can be processed on the same receiver architecture, given sufficient memory and computing power in the chipset. DRM+ can also be received with a commercially available USB receiver stick for FM and DAB and only requires minor software tweaks without the need to modify the basic Noxon hardware.
According to the report, the Electronic Communications Committee of the European Conference of Postal and Telecommunications Administrations found that the interference of digital radio systems with FM reception and aeronautical radio navigation services is so strong that a parallel use of DRM+ and analog FM would not be feasible.
However, to avoid these interference issues, it is possible to coordinate DRM+ transmitters in VHF Band III with DAB networks already allocated to this band. For the distribution of individual radio stations in small heterogeneous coverage areas with few program offerings, it finds that the transmission capacity and bandwidth needs of DAB are too high, pointing out that for the same coverage area, DRM+ needs significantly less bandwidth and only about 10 percent of the radiated transmitter power compared to DAB.
On a European level, it says that in many European countries there are not enough DAB allotments available to map all the existing local FM coverage onto DAB transmissions. The report suggests that in order to be successful, a new structure would have to be implemented, which would expand today’s local coverage areas into common regional coverage areas but that this undermines the very essence of local radio.
The overview also points out that there are currently no digital radio receivers available exclusively for DRM+ and that it is necessary to create receivers that will receive DAB and DRM as well as FM on VHF Band II, saying that the framework for the industry to adopt multistandard DAB/DRM+/FM chipsets and receivers for the European market must be clarified. This would also encompass the inclusion of DRM in the “Euro-Chip” initiative propagated by the German public-service broadcaster Deutschlandradio, the BBC and the EBU for the reception of DAB, DAB+, DMB, FM and AM bands below 30 MHz.
It explains that if local FM broadcasts are distributed on large DAB transmitter networks that cover several areas, coverage will expand and thus so will competitiveness with local providers from other areas. At the same time, local FM broadcasters will have an added financial burden if they broadcast in parallel on DRM+. This extra cost therefore must be justified by greater coverage potential or additional programs and advertising opportunities.
The study finds however that an initial comparison of DAB and DRM+ demonstrates that for the distribution of only one, two (or even three) programs, the total cost for distribution within a given area is substantially lower with DRM+ than with DAB.
The Community Media Forum Europe and the World Association of Community Radio Broadcasters have approached the EU Commission with a recommendation that DRM be used for local digital terrestrial radio, pointing out that DRM should be employed where DAB coverage is not feasible.
The German report also emphasizes that the DRM Consortium should clarify the industry interests and framework to bring multistandard chipsets and receivers onto the European market. It says the DRM Consortium should require the inclusion of DRM in the “Euro-Chip” initiative promoted by those including Deutschlandradio, the BBC and the EBU for reception of DAB/DMB, analog FM in Band II and AM below 30 MHz.
In conclusion, the report emphasized that the industry needs a statement from regulators and broadcasters about the feasibility of DRM being a complement to DAB in Germany and the rest of Europe so that multistandard receivers based on the existent multistandard chipsets can be brought to the market.