Viewers in Britain will soon be able to view several free-to-air television channels on satellite in high-definition. Channel 4 will begin broadcasting in high-definition later this year, while the BBC and ITV are set to launch their own services. Meanwhile, the Seven and Ten networks in Australia have also announced their new free-to-air terrestrial high-definition channels.

Channel 4 is scheduled to be the first British terrestrial broadcaster to offer a high-definition version of its main channel on Sky. Channel 4 HD will be available from December 2007, carrying high-definition versions of many of its programmes. The service will be available without subscription to viewers with a Sky HD box and viewing card. It is also likely to form part of the line-up for the forthcoming FreeSat platform.

“Channel 4’s aim is to offer our viewers maximum flexibility in accessing our high quality programmes and content at a time and in the format of their choosing,” said Rod Henwood, new media director at Channel 4. “HD is a fast growing consumer technology and we believe our viewers will welcome the opportunity to watch their favourite Channel 4 shows in high definition.”

According to Ofcom research, high-definition programming accounted for roughly one-third of total viewing in homes with an HD receiver. Over 40% of these viewers reported that their overall TV viewing had increased since taking HD.

Since its launch in May 2006, Sky HD has become the fastest growing additional service offered by the satellite broadcaster, although with fewer than 300,000 subscribers, it still remains a relatively small segment of the market.

The growth of high-definition television in Britain could be considerably encouraged by the launch of Freesat, with planned high-definition services from the BBC, ITV and Channel 4 available on satellite without subscription.

Ofcom has published the results of its public value test of the BBC high-definition channel, currently available on Sky as a trial service, taking it a step closer to full launch. Ofcom has concluded that the new BBC channel is likely to lead to increased take-up of high-definition television by viewers, but notes that “there is no consensus about whether HDTV will become a mass-market proposition in the UK”.

While generally seeing the proposed BBC HD channel as a positive move, Ofcom did note that it could have a negative impact on internet protocol television services if there is significant demand for high-definition programming, as the current infrastructure will not allow such services to be delivered by broadband to a significant number of consumers.

Ofcom specifically recommends that the BBC should work to the objective of delivering the channel on IPTV as soon as it is technically feasible to do so. In addition, Ofcom notes that making high-definition programmes available for download will also impose greater costs on internet service providers. It recommends that the BBC Trust should take such costs into account as “they may offset the public value generated by the service”.

The BBC is planning to make the high-definition service available on satellite, cable and terrestrial television, with services delivered over broadband when technically feasible. A limited overnight service may initially be offered on terrestrial, which will require new compatible digital video recorders. Following analogue switch-off, the full schedule may be transmitted on terrestrial television, subject to sufficient spectrum capacity being available.

The British public service broadcasters are lobbying for additional spectrum for high-definition as a result of the digital dividend created by turning off analogue television transmissions.

This is strongly opposed by the satellite and cable operators, who want to maintain their advantage in delivering high-definition services. At the Royal Television Society convention in Cambridge, James Murdoch, the chief executive of Sky protested: “You have people playing for this and to suddenly say it has crossed the threshold of public necessity is preposterous”.

Australian viewers are meanwhile to receive two new free-to-air high-definition television channels. The Seven and Ten networks have announced new services, to be launched in December. They will be the first new commercial free-to-air channels in Australia for more than forty years.

Australia has had high-definition digital terrestrial television for some time, but mainly simulcasting existing channels, rather than what they call multichannel. Many of these services have also been less than true high-definition. The Seven Network only recently moved up from 576 line progressive transmissions, which are still used by SBS, while the ABC broadcasts in 720 line progressive format.

Under changes to the Broadcasting Services Act made last year, commercial broadcasters have been able to transmit a single separate high-definition channel from the beginning of 2007 and a further standard definition digital channel from January 2009.

“Seven has been a long time supporter of multichannelling as a key driver for digital television takeup,” said David Leckie, the chief executive of the Seven Network. “Our plan is to build on our leadership position in Australian drama, sport, news and entertainment and establish a broad multiple channel presence to further develop the strength of the free-to-air digital platform over the coming three years.” It follows the announcement of a partnership between Seven and TiVO earlier in the year.

Grant Blackley, the chief executive of Ten, said: “We are no longer bound by a single linear channel, and Ten-HD is a natural next step in our goal to make our content as widely available as possible to consumers.” He also cited Ten Digital’s online and mobile activities and the recently-concluded retransmission agreement with Foxtel as examples of their multi-platform distribution strategy. He also confirmed that Ten-HD would be transmitted in 1920×1080 interlaced format, with 5.1 channel Dolby surround sound.

High-definition is expected to drive the further growth of digital television. Only around 30% of Australian homes currently have free-to-view digital television, but high-definition displays are selling well, with almost ten million expected to be sold in the country in the next five years.