On the Radio with DVB-T2 Lite
The Copenhagen based Open Channel wants to broadcast digital radio using the DVB-T2 Lite profile. DVB-T2 is already in use broadcasting digital television in a number of countries and could easily be used to broadcast digital radio in Denmark. It is my opinion that the standard is superior to DAB+ and that is why we have applied for a DVB-T2 trial licence on a 1.7 MHz channel bandwidth, also known as a T-DAB frequency, from The Danish Radio and Television Board.
A recent report by The Danish Agency for Libraries and Media outlined the numerous problems and difficult choices that must be taken in connection with its strategy for the future of radio broadcasting in Denmark.
DAB+, the upgraded version of DAB, the known and safe choice, will triple the number of transmitted channels, but if Open Channel relies on DAB transmission technology, including the first layer of error correction, it will be limited to the performance capabilities of the DAB transmission layer.
The technologically superior choice is DVB-T2 that will provide a 2.5 to 4 times increase in capacity over the DAB/DAB+ standard under the same broadcasting conditions (2 ½ – 4 Mbit/s vs ~1MBit/s). Furthermore, DVB-T2 will be better for indoor reception and be less sensitive to impulse noise (sparks). It is also believed that the standard is better suited for in-car reception. Alternatively, if the aim is to transmit the same capacity as DAB/DAB+ (~1 Mbit/s), DVB-T2 would allow you to select parameters for higher robustness. The required signal strength for 1 Mbit/s transmission could be reduced by 3 to 5 times, compared to DAB, with the equivalent reduction of the transmission costs.
The new DVB-T2 Lite profile, a subset of DVB-T2, will allow more cost efficient receiver implementations for very low capacity applications such as digital radio and mobile broadcasting.
Open Channel has already undertaken DVB-T2 field trials with three technology partners: ProTelevision Technologies (DK), T-Vips (N) and Dektec (NL). They have all subsequently added support for 1.7 MHz bandwidth to their DVB-T2 products.
We made our original DVB-T2 trials with what is now known as the DVB-T2 Base Profile, and have proven that we can transmit radio channels in separate PLPs, using the ProTelevision PT2082 DVB-T2 modulator, the T-Vips CP560 T2 Gateway, and receive the signal with the Dektec DTA-2135-T2 DVB-T2.
For the 1.7 MHz trials, Open Channel has applied for a licence to transmit on VHF Channel 9D in the Greater Copenhagen area. The Agency for Libraries and Media are expected give their approval at their next meeting on August 30th, at which point the National Telecommunications Agency can start the coordination process with the neighboring countries of Sweden and Poland. This is expected to take a further four weeks. We don’t expect to be ready to go on air before November.
When our 1.7 MHz trials start, we will use parameters from the common subset of the T2 Base and T2 Lite profiles. Once receivers for DVB-T2 Lite become available, we will change the signaling and start to investigate the full possibilities of T2-Lite.
Our DVB-T2 trial has generated a lot of interest, and many manufacturers have expressed interest in doing 1.7 MHz implementations in their iDTVs and STBs for our experiment. Digital handheld devices using DVB-T2 have even been discussed.
Information on our DVB-T2 trials can be found on page 6 of DVB Scene 35.
About Open Channel
Based in Copenhagen, Open Channel, a subsidiary of U-Media, distributes free-to-air television programming on UHF Channel 35 / MUXKBH. The company has been conducting DTT trials since 2006 in the Greater Copenhagen area. The coverage area of MUXKBH consists of over 700,000 homes, equal to 28 percent of all Danish households. Over this period, it has broadcast several 24 hour channels seven days a week.
Since May 2010 Open Channel has started broadcasting using DVB’s second-generation digital terrestrial TV standard, DVB-T2, on UHF Channel 67 / MUXKBH-2 in the Greater Copenhagen area.
