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    Mobile TV and DAB


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    Commentary on mobile TV in Europe frequently focuses on one technology in particular – DVB-H, or digital video broadcasting for handhelds. There is no doubt that this up-and-coming standard shows clear promise, but in the UK, the fact that no spectrum has yet been allocated for DVB-H means it will not be available for at least three to five years, and in some areas it may not be available until 2012. The debate over DVB-H, however, often overlooks the fact that there is already a well-established and effective broadcast technology and infrastructure available – Digital Audio Broadcast (DAB).

    DAB – not just about radio
    Some commentators are under the false impression that DAB is not suitable for mobile TV, being an audio broadcast mechanism. However, DAB was designed from the outset to deliver multimedia content such as video and streamed TV, and the operational DAB networks can support these services now. In the UK, 46 DAB multiplexes (blocks of frequencies) are already allocated, and have the regulatory capacity to broadcast multimedia content, up to a limit of 20% of the capacity of each multiplex. Moving forward, even greater capacity will be available; the UK regulatory body, Ofcom, has recently stated it will increase this limit significantly.

    Why DAB?
    DAB is a truly effective and efficient standard for transmission, for a number of reasons. DAB has true multimedia capacity and, together with streamed TV, it has the potential to enable the end-user to download files, web pages and games, promising a truly holistic ‘entertainment experience’. For example, DAB supports an Electronic Programme Guide (EPG), to allow viewers to easily navigate available TV and radio content and these services are being broadcast now on most of the UK multiplexes. Using DAB, a mobile device decodes less data so it has a lower power requirement than a device using DVB-H. DAB is less prone to ‘fading’ of the signal in the mobile environment and service acquisition and switching times are shorter.

    Currently, the UK DAB networks are designed for reception by static radio sets and car radios, both of which have large antennae that are not feasible for mobile phone use. In order to strengthen the signal for reception by mobile devices, additional infill transmitters are needed. Improvement of antenna technology for the mobile devices themselves is also necessary; there are a number of solutions in development to address this, but as many people will wear earphones to use mobile TV services, one of the most realistic market entry propositions is to build the antenna into a headset which plugs into the mobile phone.  So, to provide mobile TV services, investment in existing DAB networks is incremental and relatively small in comparison with building a DVB-H network from scratch.

    DAB around the world
    Scepticism also prevails around the use of DAB for mobile TV. However, DAB networks are already available to 80% of Europe, and there are currently more than 800 DAB services reaching 475 million people in 40 countries around the world. This infrastructure is already established, whereas we are still waiting for the first commercial DVB-H network to be built. Many countries also face  spectrum licensing hurdles in relation to DVB-H, whereas DAB is already significantly licensed across Europe. Pilots are planned in Germany and France, where there is uncertainty that DVB-H will be licensed.

    But why is it necessary to have this debate about the most suitable standard? The answer lies in the necessity of bringing mobile TV to market rapidly. To launch commercially viable TV-to-mobile services quickly, DAB is currently the only viable solution available, from a spectrum licence and network perspective.

    In the midst of this debate, however, the industry should not lose sight of the fact that standards never stand still, and today’s technology may not constitute tomorrow’s success factor. The key to long-term success in the mobile TV arena is having the flexibility to adapt to the most suitable technology currently commercially available, and it seems likely that devices will need to support more than one technology in the future. Ultimately, of course, the choice of technology platform is the mobile operator’s dilemma; consumers will not care about the technology used to broadcast their TV services, just as long as they receive high-quality compelling content from their operator, with affordable pricing.

    By Emma Lloyd, COO of BT Movio