UK broadcasters BBC, ITV, Channel 4 and Five have joined forces to launch the UK's first HD trial broadcasts to terrestrial aerials. A 450-strong audience sample collected their trial HD set-top boxes last week for the closed technical trial which is due to last six months.
The trial is designed to offer participating broadcasters and their technical partners valuable lessons about delivering HD broadcasts on a digital terrestrial network and also research how the audience enjoys this new format. Crucially, it will help to discover whether there could be HD broadcasts on Freeview in the future.
The trial is being conducted under an Ofcom licence which strictly limits the number of receivers and forbids reception of the trial stream by general members of the public. It consists of low power transmissions from Crystal Palace in London on frequencies unsuitable for high-power broadcasting.
Humax and ADB (Advanced Digital Broadcast) supplied the HD set-top boxes for the trial. National Grid Wireless (NGW) is transmitting the BBC's HD stream, which went on air last month, and Red Bee Media provides play-out services. Arqiva is transmitting the multiplex shared by ITV, Channel 4 and Five, with Grass Valley providing broadcast playout and video encoding equipment. Siemens Business Services is providing technical support for the BBC's HD trial.
The test broadcasts will use MPEG4 video coding, 8K carriers and 64QAM modulation at launch. Different parameters may be tested during the trial period.