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Digital terrestrial television in the United Kingdom encompasses over 100 television, radio and interactive services broadcast via the UK's terrestrial television network and receivable with a standard television aerial. The majority of services, including the five former analogue terrestrial channels and their offshoots, are broadcast free-to-air, and a further selection of encrypted pay TV services (such as BT Sport) are also available. Freeview is the only prevailing digital terrestrial television (DTT) service (Top Up TV service was closed on 31 October 2013 and BT TV offers only BT Sport on DTT – their other services are carried via IPTV signals). The digital broadcasting technology adopted in the UK is the DVB-T system (Digital Video Broadcasting – Terrestrial) carrying compressed digital audio, video and other data in a combined transport stream, using COFDM modulation. A total of six 'multiplexes' are broadcast in the UK, guaranteed to reach over 90% of the country when analogue signals are fully switched off. Three of the six multiplexes, carrying the free public service channels operated by the BBC, ITV, Channel 4, S4C and Channel 5, are guaranteed wider coverage still, reaching 98.5% of the country including areas dependent on low-power local relays.〔http://stakeholders.ofcom.org.uk/binaries/research/tv-research/no3factsheet.pdf〕 The digital switchover for terrestrial television signals was completed on 24 October 2012. ==Receiving and recording== Digital Terrestrial Television is commonly received by means of a compatible set-top box or integrated digital television (IDTV), connected to an appropriate receiving antenna. In most cases, reception is possible using aerials originally used for analogue television. Transmissions may be recorded in many ways – such as via the connection of a set-top-box to an existing 'analogue' video or DVD recorder, or by the use of newer models of such recorders which have built-in digital tuners. However the most common option is by the use of set-top-boxes which incorporate a hard disk drive, and allow the recording of the digital signal directly to disk, for later replay. Recording on such boxes, known as Personal Video Recorders or PVRs, is more convenient, as programmes may be easily selected for recording from an on-screen programme guide, with no need to specify explicit start and end times for recordings, and no need to program more than one piece of equipment. Many television services which incorporate DTT channels in their service offering – e.g. Top Up TV, BT TV, and TalkTalk Plus TV, offer set top boxes with such a recording facility. Non-subscription DTT PVRs are also available and are often sold under the 'Freeview+' banner (formerly Freeview Playback.) There also exist a variety of solutions to enable the viewing and recording of DTT programmes on personal computers, with various TV cards or USB tuners available for use with a variety of software packages, including MythTV and Windows Media Center. Most cards or tuners include their own software in the package also. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Digital terrestrial television in the United Kingdom」の詳細全文を読む スポンサード リンク
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