All the major UK broadcasters are testing HD broadcasts to terrestrial aerials starting this week, the BBC has announced.

BBC, ITV, Channel 4 and Five are sending out HD broadcasts to 450 HD set top boxes.

The trial will last 6 months, and will show up any weaknesses in the format or broadcast so that they can be remedied.

The number of receivers has been limited by the Ofcom license under which the trial is operating. The license also forbids reception of the trial stream by the general public.

Programs the will be broadcast in the format include Wimbledon and World Cup coverage on the BBC and Lost on Channel 4.

The test broadcasts will use MPEG4 video coding, 8K carriers, and 64QAM modulation at launch, but different parameters may be tested during the 6 months period.