The great thing about Freeview is that once you've paid your telly licence, there are a lot of channels that you don't need to pay extra to get. But the trouble is that the selection is limited compared to offerings from Sky or Virgin. But that could all change as Ofcom has new proposals that could increase the number of channels available on digital terrestrial television and perhaps even herald that proper start of high-defition television without a satellite or cable in sight.

According to the proposals, an HD service could start as early as 2009, but would require viewers to ditch their current set-top boxes for ones that could decode the new signals.

The watchdog announced that the four main terrestrial broadcasters (BBC, ITV, Channel 4 and five) had signed a "non-binding memorandum of understanding" pledging to launch HD services between two and five years time.

The proposals outlined how the service could be upgraded. It said the digital switchover would allow a change in broadcast technology that would increase the capacity of DTT by 20 per cent (which would mean an extra channel per mux). Also, improving efficiency in current broadcast technologies could squeeze out some extra bandwidth.