DVB-H recommended to be Europe-wide mobile TV system

20th March 2007

The European Commissioner for Information Society and Media, Viviane Reding, has said that

“The industry should agree on one single standard. I believe this should be the DVB-H family of standards.”

And she went on to suggest that if the industry and member states failed to agree on one standard she would be forced to “intervene with regulatory measures.”

Ignoring the issue of which system is best for a moment, she is absolutely right that it would be far better if only one mobile TV system were used across Europe, because at the moment we face seeing multiple mobile TV services launched using different and incompatible mobile TV systems, and all that would achieve is that the same TV channels would be duplicated on all of the different systems, which is simply an incredibly wasteful use of spectrum -- we wouldn't dream of having more than one Freeview system duplicating the same TV channels, so why on earth would it be a good idea to do this with mobile TV? It wouldn't.

And on the issue of which technology is the best one to use, DVB-H is obviously vastly superior to both of the DAB-based systems (T-DMB and DAB-IP). DVB-H is more spectrally efficient, uses stronger error correction coding, which leads to more robust reception quality, and is cheaper to transmit per mobile TV channel.

So I think the European Commissioner has made the right decision in backing DVB-H as the sole mobile TV system for Europe.

However, there are (unsuccessful) commercial T-DMB and DAB-IP services that have already launched, such as the DAB-IP mobile TV service on the Digital One UK national multiplex, and there's another small-scale T-DMB service broadcasting in Germany, so the companies already transmitting mobile TV on a DAB-based mobile TV system won't exactly be deliriously happy with this decision, but it is nonetheless the right decision, and those TV channels affected should be forced to broadcast on DVB-H as soon as possible.

DVB-H already has far more support around the world than the DAB-based mobile TV systems, as there are already a large number of DVB-H commercial services and trials, whereas there are very few T-DMB or DAB-IP trials or commercial services so far.

The reason why DVB-H is a superior mobile TV system to T-DMB and DAB-IP is due to its use of far stronger error correction coding. DVB-H uses a 3-layer error correction coding scheme, with the 2 inner layers of coding being the same as those used by T-DMB and DAB-IP, but with an extra very strong outer layer of coding called the MPE-FEC (Multi-Protocol Encapsulation Forward Error Correction), which allows DVB-H to transmit using 16-QAM at the same signal-to-noise ratio (SNR) as T-DMB and DAB-IP needs with its differential QPSK modulation -- 16-QAM can carry 4 bits per modulation symbol whereas QPSK can only carry 2 bits per modulation symbol, which leads to DVB-H being a lot more spectrally efficient.

DVB-H also uses synchronous modulation whereas T-DMB and DAB-IP use the old DAB system's differential modulation, which incurs a 3 dB SNR penalty, which adds to DVB-H's superiority over T-DMB and DAB-IP in terms of the transmission schemes used.

The power consumption is also lower with DVB-H than T-DMB/DAB-IP due to DVB-H's use of 'time-slicing', where the RF front-end is switched off in between very short transmission bursts of the channel you want to receive, which reduces the power consumption significantly.

Another factor that will likely have motivated the European Commissioner is that DVB-H is a European-based standard, whereas T-DMB (which is the leading DAB-based mobile TV system) is a South Korean-based system.

It should also be remembered that when mobile TV was first touted in Europe DVB-H was the first on the scene and it was expected to be the Europe-wide mobile TV system, and it has only been due to the Korean companies and DAB broadcasters that T-DMB and more recently DAB-IP have tried to barge in on the action.