Digital television in the United Kingdom

There are four major forms of digital television (DTV) broadcast in the United Kingdom: a direct-to-home satellite service from the Astra 28.2°E satellites provided by Sky UK, a cable television service provided by Virgin Media (known as Virgin TV); a free-to-air satellite service called Freesat; and a free-to-air digital terrestrial service called Freeview. In addition, an IPTV system known as BT Vision is provided by BT. Individual access methods vary throughout the country. 77% of the United Kingdom has access to HDTV via terrestrial digital television. Satellite is the only source of HDTV broadcast available for the remaining 23%.

The initial attempt at launching a digital terrestrial broadcasting service, ONdigital (later called ITV Digital), was unsuccessful and the company went into liquidation. Some observers have argued that this failure stemmed from the Government's eagerness in having sold off too much TV spectrum to launch Channel 5 (the last UK terrestrial analogue channel), and ONdigital's short-sightedness in over-extending its use of available bandwidth: using poor signal encoding to maintain compatibility with early set-top boxes, optimising their broadcasts for capacity rather than reliability, and cramming too many channels into the available bandwidth.

ITV Digital was replaced in late 2002 by Freeview, which uses the same DVB-T technology, but with higher levels of error correction and more robust (but lower-capacity) modulation on the "Public Service" multiplexes in an attempt to counter the reception problems which dogged its predecessor. Rather than concentrating on Pay TV services, Freeview uses the available capacity to provide a free-to-air service that includes all the existing five free-to-air analogue terrestrial channels and about twenty new digital channels. All services are transmitted in standard definition—576i in the UK—many using an anamorphic widescreen format.

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