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%.