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Hello. I'm Andrew Murphy, a Senior Research Engineer in the "Distribution Core Technologies" section here at ³ÉÈËÂÛ̳ R&D. Our section carries out research into the technologies that underpin the distribution of the ³ÉÈËÂÛ̳'s TV, radio and interactive services both now and in the future.

Over this and subsequent posts I'll aim to tell you more about the work of the various teams in the section in areas such as high definition radio cameras, video coding, white spaces and the future of radio. I'm going to concentrate on DVB-T2 now, however, as yesterday marked the technical launch of Freeview HD which uses DVB-T2 as its physical layer.

You may have seen from Ant's post that our section's work on DVB-T2 was recognised by an RTS Innovation Award. As part of the T2 team, I was lucky enough to be at the awards ceremony and thought I'd give some background into the work that was recognised by the award.

is a new transmission standard (so you will need a new T2-compatible receiver to decode it) that typically gives 50% more capacity than the current digital terrestrial television standard used in the UK, DVB-T. It achieves this through a combination of more advanced modulation techniques, improved error correction coding and time interleaving as well as more efficient signalling and allocation of pilots. More details can be found .

The timescale for the development of DVB-T2 has been incredibly tight. In just three years it's gone from an initial study mission and call for technologies through to a published and the manufacture of silicon and imminent launch of consumer set top boxes. This process has been backed up by countless simulations, verification work, testing and detailed field trials.

That short summary of course doesn't do justice to the huge amount of effort put in by us and numerous other companies from all around the world who have worked to make DVB-T2 a reality.

Our section at R&D is split into two teams overseen by section lead, Nick Wells, who is also chair of the T2 group within the DVB Technical Module.

The hardware development team is led by Justin Mitchell. Justin posted last year about the development of the world's first end-to-end DVB-T2 modulator/demodulator chain. Justin and his team are focussing on adding features to our modulator and demodulator both of which have been licensed to manufacturers as a way of encouraging the availability of T2 equipment and getting value back from work we would have needed to carry out anyway.

The T2 specification team (of which I'm a member) is led by Chris Nokes. This covers our contributions to the DVB-T2 working group, inputs to the T2-related specifications, T2 field trials and work within the (DTG). Our team is also working closely with manufacturers to provide feedback on the performance of their DVB-T2 receivers which we test in our labs.

Personally, I've been helping to develop realistic test streams for T2 Multiple Physical Layer Pipes (PLPs). Multiple PLPs are an advanced feature of DVB-T2 that enable service-specific robustness. So, for example, a single T2 transmission could contain a mixture of high definition services aimed at household TVs fed by roof-top aerials as well as some low-bit rate, more rugged, services aimed at portable receivers.

There are no plans to use multiple PLPs in the UK at present (the DVB-T2 channel capacity will all go towards high definition TV services) but we had to be sure that all the set-top boxes supported multiple PLPs at launch in case the UK had a requirement for them in the future. It's only by making test streams such as this available that it's possible for manufacturers to validate that their receivers would work with future multiple PLP services.

Alongside this I've also been chairing a sub-group within DVB-T2 to verify the T2 Modulator Interface standard (). Whereas DVB-T transmissions are completely defined by the MPEG transport stream that they carry, the flexibility of T2 and the inclusion of multiple PLPs in the standard means that a transport stream is not necessarily an unambiguous description of the on-air T2 signal. Why does this matter? Well, for synchronised Single Frequency Network (SFN) operation, every transmitter must output the same signal at a precisely defined time instant. The T2-MI allows this to happen by telling the modulator exactly what to transmit when. The interoperability of T2-MI was successfully demonstrated at a plug-fest at the end of October where the first T2 SFN on a wire was created using equipment from different manufacturers fed by a single source of T2-MI.

The RTS Innovation Award recognised the hard work of everyone in my section working on DVB-T2 but there are many more people in other sections at R&D and around the ³ÉÈËÂÛ̳ and in industry working hard to make sure that the launch of Freeview HD goes as planned and that the new transmissions integrate correctly with the existing DVB-T transmissions.

Watch this space...