Upgrading digital TV

An upgrade to Digital Terrestrial Television (DTT) in the UK could mean more new channels and services, if proposals from Ofcom are given approval.

Ofcom says that its proposed upgrade would create more capacity, allowing high definition television channels on DTT – on which Freeview operates – as early as 2009.

Ofcom believes that the upgrade could be complete in time for digital switchover in the Granada television region, which is due to take place in late 2009 /early 2010. The new services would then be available as switchover is rolled out across the rest of the UK, completing with four HD services being available by 2012.

Importantly, the proposals rely on embracing two new standards - MPEG4 and DVB-T2. The MPEG4 compression standard is expected to be up to twice as efficient as the current MPEG2 standard that is in use, while the new European transmission standard DVB-T2, will increase capacity by at least 30 per cent.

Then there is the issue of clearing the space for the new channels. Terrestrial television is broadcast on multiplexes. A multiplex is a group of digital TV channels that are mixed together for broadcast, which are then unmixed by a set-top box. Ofcom proposes to relocate existing channels on one of the multiplexes to use the spare capacity on the others. The freed-up multiplex would be then be upgraded to use the new technologies and standards.

Although the DTT upgrade would bring more choice to consumers, viewers who wanted to access the new services would need to buy a new DTT set-top box or integrated television, which was compatible with MPEG4 and DVB-T2.

However, viewers with existing DTT set-top boxes or integrated televisions would still be able to access Freeview services with their current equipment.

The regulator has produced a consultation document that sets out how the changes could be achieved. It can be found here.