TVs

BBC DVB-T2 trial: Bringing HD to Freeview

Ten years after the start of digital TV in the UK, the BBC is beginning its DVB-T2 trial to work out how to get high definition programmes to you over Freeview

It may not seem like that long, but we've had digital TV in the UK now for ten years, with the ill-fated OnDigital starting up in 1998, around the same time Sky launched its own digital service. Ten years is a long time in technology, and as with all such things, there have been significant advances since the DVB-T and MPEG-2 system was put into place.

The BBC is now testing the DVB-T2 system, which will probably be used for the new multiplex Ofcom is hoping to create when analogue gets its marching orders in 2012. People in some parts of the country will get the benefit earlier, with a few lucky places going live next year.

So what does DVB-T2 offer over vanilla DVB-T? At the very least, the new standard will offer an increase in efficiency, which in turn means more bandwidth will be available on the multiplex. That, combined with a switch from MPEG-2 to MPEG-4, should enable a decent amount of HD. The current estimate is that in 2009 there will be three HD channels available, one of which goes to the BBC and two that ITV, Channel 4 and Five will have to fight over.

Interestingly, the DVB-2 system won't be making use of MIMO, which we got very excited about after a trip to BBC R&D at Kingswood Warren. That means existing aerials will be fine, and only your set-top box (or TV) will need to be replaced to receive the new services.

The planned switch to DVB-T2 isn't without controversy. When the time comes, the channels that currently reside in this spectrum space will be moved to another multiplex, which means either a reduced bit rate for those services, or the loss of some channels in certain regions. Additionally, three HD channels on one multiplex seems like a push -- with the increased capacity, each multiplex should have around a 30Mbps data rate, which would leave around 10Mbps per channel -- not an enormous amount, even for MPEG-4 HD.

If you're thinking of finding the test transmissions, we'll wish you the best of luck. If this trial is anything like the MIMO one the BBC ran, it won't broadcast for very many hours each day and it won't stick to a published schedule. It's also unlikely there will be any real video being transmitted (it's likely to be a test signal). Oh, and you'll need a DVB-T2 compliant receiver as well, which isn't something you can get in Argos. –Ian Morris