DTV transition

The digital television transition, also called the digital switchover, the analog switch-off (ASO), or the analog shutdown, is the process in which analog television broadcasting is converted to and replaced by digital television. This primarily involves the conversion of analog terrestrial television to digital terrestrial. However, it also involves analog cable conversion to digital cable, as well as analog to digital satellite television.

In many countries, a simulcast service is operated where a broadcast is made available to viewers in both analog and digital at the same time. As digital becomes more popular, it is likely that the existing analog services will be removed. In some cases this has already happened, where a broadcaster has offered incentives to viewers to encourage them to switch to digital. In other cases government policies have been introduced to encourage or force the switchover process, especially with regard to terrestrial broadcasts. Government intervention usually involves providing some funding for broadcasters and, in some cases monetary relief to viewers, to enable a switchover to happen by a given deadline.

The switchover for individual countries varies; in some countries it is being implemented in stages as in Australia, India and the United Kingdom, where each region has a separate date to switch off. In others, the whole country switches on one date, such as the Netherlands, which switched off all analog services on 11 December 2006. Some countries have different switch off dates for each channel, such as China where CCTV channels 1-5+ were switched off first.

The Geneva 2006 Agreement set 17 June 2015 as the date after which countries may use frequencies currently assigned for analog television transmission for digital services, without being required to protect the analog services of neighbouring countries against interference. This date was generally viewed as an internationally mandated analog switch-off date, at least along national borders. The European Commission has recommended that digital switchover should be completed by 1 January 2012 - Commission Recommendation 2009/848/EC, of 28 October 2009.

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