An independent committee of industry experts has come up with a new proposal for using digital terrestrial spectrum to provide HD channels.

Speaking at the DTG (Digital Television Group) annual summit, Dr Ian Childs of the Digital 4.0 working group proposed that space for up to twelve HD channels could be made available to broadcasters if Ofcom freed up two national single frequency networks after digital switchover.

This would be in addition to the four HD public service channels that will be possible by 2012 thanks to Ofcom's re-organisation of the current multiplexes and the introduction of new coding technologies, DVB-T2 and MPEG4.

Childs, who described the proposal as ‘fairly radical', said the new channels could be introduced in 2013 once digital switchover has been completed.

He also said that the use of single frequency networks could eventually enable up to 40 HD channels in the UK.

The multiplex with the four PSB channels on it will have nearly 100% UK coverage while the two single frequency networks would be available to 70% of the country.

The independent committee wants the industry to discuss its new proposals and debate the issue further.

The DTG represents manufacturers, retailers and broadcasters. It has recently been critical of Ofcom's plan to use DVB-T2 as part of its plan to get HD channels on Freeview by 2009. The DTG believes that the technology will not be ready in time.