According to a BBC News article last week on the DTV transition in the U.K., the country's media regulator Ofcom says the U.K. can only be fully digital by the government's 2012 target date if it switches over region by region and if the switchover begins in 2008. The BBC article includes a timetable for the switchover, with the Wales, the Border and West Country ITV regions switching off analog in 2008. Ofcom cautioned that, "The actual year in which switchover begins and regions subsequently convert remain a matter for government to determine as part of its overall switchover policy. Ofcom remains committed to the earliest practical switchover policy, while recognising the need to take proper account of the interests of viewers and other key parties."
I looked for information on the proposal on the Ofcom Web site, but didn't find the timeline. I did find a consultation (similar to a Notice of Proposed Rulemaking or Notice of Inquiring in the U.S.) describing some of the engineering decisions that have to be made before the switchover can be completed. The consultation, Planning Options for Digital Switchover, describes current analog TV terrestrial coverage and various options for digital TV terrestrial facilities. Comments were requested on whether transmitters should be switched from 2K to 8K COFDM carrier format. The trade off between power level, modulation method--16QAM versus 64QAM carriers, and channel capacity are also discussed.
Ofcom's summary of the consultation document notes, "while coverage can be improved by increasing power levels or by broadcasting at the most robust transmission mode, doing so may increase the cost and the implementation risk of digital switchover. A change in the transmission mode will also affect the capacity of the DTT network. As a result, there are important trade-offs to be made in deciding on the most appropriate mix of these variables. This consultation considers, and seeks views on, those trade-offs."
The summary adds, "On DTT coverage, this consultation considers five alternative combinations of sites, mode and power. Three of these appear to result in coverage levels which would match or even exceed existing analogue levels. However, each of them would entail different costs and other implications and Ofcom wishes to hear the views of respondents on their relative merits in light of the limited data currently available to allow an objective evaluation."
For more information on DTV decisions in the UK, see Planning Options for Digital Switchover.
