Digital terrestrial television in the United Kingdom encompasses over 100 television, radio and interactive services broadcast via the United Kingdom's terrestrial television network and receivable with a standard television set. The majority of digital terrestrial television (DTT) services, including the five former analogue channels, are broadcast free-to-air, and a further selection of encrypted pay TV services (such as Racing TV) are also available. Freeview is the only DTT service since Top Up TV closed in 2013.
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 modulation. A total of eight national and one local 'multiplexes' are broadcast in the UK, guaranteed to reach over 90% of the country. Three of the 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.
In the UK, the switchover from analogue to digital TV started on 17 October 2007 and was completed on 24 October 2012. Each group of regional transmitters had its analogue broadcasts switched off at a certain point between those dates.
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.
Features Digital Terrestrial Television provides many more channels. For some viewers it offers much improved reception compared to analogue broadcasts (although these had been entirely discontinued in the UK by 2012), including 16:9 anamorphic widescreen. A number of interactive services are also offered.
An eight-day Electronic Programme Guide (EPG) is available and allows viewers to see programme descriptions and broadcast times well in advance. PVRs can make use of this facility when setting recording timers.
Early history Development and launch Digital terrestrial television launched in the UK on 15 November 1998, just after digital satellite television on 1 October 1998. The technology required that the UK government license the broadcast of channels in six groups, or multiplexes (abbreviated to 'mux'), labelled 1, 2, A, B, C, and D.
The Independent Television Commission allocated half the capacity of a multiplex to each of the existing analogue terrestrial channels. This meant the BBC got a multiplex to themselves (Multiplex 1), ITV and Channel 4 shared Multiplex 2 (though 3% of the capacity was given to Teletext Ltd.) and Channel 5 and S4C shared Multiplex A. The remaining spectrum (Multiplexes B, C and D) was then auctioned off. A consortium made up of Granada and Carlton (members of the ITV network, who later merged to form ITV plc) and BSkyB successfully bid for these licences, and set up the subscription ONdigital service, though BSkyB left the consortium prior to launch.
The BBC used some of its multiplex for three of its new television services: BBC Choice (which had started on 23 September 1998 with four national variations), BBC News 24 and BBC Parliament (albeit in sound only). ITV initially used their space to house ITV2 (from 7 December 1998) in England and Wales, You2 (later UTV2) in Northern Ireland and S2 in Scotland (later both replaced by ITV2), as well as GMTV2 during the early mornings. Channel 4 used their space for subscription channels FilmFour and E4 which, although not part of ONdigital, were only available through an ONdigital subscription. The nationwide coverage provided by multiplex 2 enabled Channel 4 to be received terrestrially throughout much of Wales for the first time in its history, where previously only S4C had been available. Consequently, S4C's digital service S4C Digidol carried only Welsh-language programming, in contrast to S4C analogue which also carried English-language programmes commissioned and transmitted by Channel 4 in other parts of the UK.
Channel 5 sold its half of Multiplex A to the owners of the other half, S4C, who set up a subsidiary called S4C Digital Networks (SDN) to manage the multiplex. They rented most of it to ONdigital, and some space to the BBC who launched BBC Knowledge on 1 June 1999, at a time when technical capabilities limited the number of stations it could carry on its own multiplex. S4C chose not to carry S4C Digidol and its newly launched digital Welsh Assembly station S4C2 outside Wales, preferring to sell the space instead. Consequently, some ONdigital services were not available on Welsh transmitters.
While the BBC was seemingly concerned with delivering a service of good technical quality, other broadcasters chose to deliver a larger number of channels rather than optimise service reliability and picture quality.
ITV Digital
ONdigital was unprofitable from the start, and renaming the service ITV Digital on 11 July 2001 failed to help the matter. All subscription services except E4 and FilmFour went off-air on 1 May 2002 after the consortium collapsed, explained as being due to paying too much for the television rights for The Football League. However, the choice of 64QAM broadcast mode, the fact that at least 40% of homes would need new aerials to receive it, a high churn rate, an insecure and hackable encryption system, the cost of having to provide free set-top boxes, and aggressive competition from BSkyB all contributed to ITV Digital's spiralling costs before shareholders Granada and Carlton called a halt to the venture.
Freeview
When ITV Digital collapsed, the rights reverted to the regulator and the Independent Television Commission invited bids for the space on Multiplexes B, C and D. The Freeview consortium was formed by the BBC, transmitter company National Grid Wireless (known at the time as Crown Castle UK) and BSkyB. This consortium (legal name DTV Services Ltd and trading under the "Freeview" brand) won and launched a new service. Dropping the failed ITV Digital business model, Freeview launched on 30 October 2002 with free television channels only, and made digital radio stations available on television receivers for the first time.
The BBC controlled one Multiplex (B) for its own services, and Crown Castle/National Grid the other two (C & D) for commercial services, though the Community Channel also operated on Multiplex B. The BBC's second multiplex allowed it to televise BBC Parliament where it had previously only been available in sound, allowed BBC Knowledge and its successor, BBC4, to stop renting space from SDN for coverage, and allowed for special video screens in its interactive service BBCi for use during selected sporting events.
On 11 October 2005, ITV plc and Channel 4 joined the Freeview consortium. In the same year ITV plc bought SDN, and thus gained control of Multiplex A.
Top Up TV
The space ITV Digital had rented on other multiplexes initially became empty again, but some was rented out to allow new channels to launch. In May 2004 Top Up TV was launched to provide subscription content in hitherto unused space on multiplex A rented from Channel 5, and additional services transmitted by Channel 4 on their own capacity on Multiplex 2.
Turner Classic Movies purchased its own slot throughout England, Scotland and Northern Ireland from the multiplex owner, SDN, but rented from Sit-up Ltd in Wales, timesharing with bid tv. Multiplex A was ultimately owned by ITV Plc via its SDN acquisition, but ITV only had involvement with Top Up TV channels via Channel 5. In September of the same year, Top Up TV began operating solely on Multiplex A, as Channel 4 reclaimed the space on Multiplex 2 for its own services More 4, E4, and later Film4.
In October 2006, Channel 5 launched two new free-to-air digital channels, Five Life and Five US, using capacity formerly leased out to Top Up TV. This left Top Up TV with a reduced number of video streams. In November 2006, the company launched Top Up TV Anytime, where overnight "downloads" were recorded by a proprietary personal video recorder (PVR). At the same time, they started reducing the linear service.
2006 changes to regulations On 19 April 2006, Ofcom ruled that, on request of each multiplex operator, the 'free-to-air channels only' requirement put in place at the launch of Freeview in 2002 could be lifted on Multiplex B, C and D. Ofcom said that the digital television market had changed significantly since 2002.
During the consultation, 9 of the 12 responses from broadcasters were in favour of removing the restriction. These included the BBC. The BBC agreed that the digital television market had changed substantially since 2002, and that Top Up TV probably could not afford the current cost of DTT slots anyway. The BBC suggested that the deregulation should be conditional on a number of further changes to regulation. These included that Ofcom change the transmission mode of broadcast on all multiplexes from 16QAM to 64QAM so more services could be broadcast. However, Ofcom rejected these suggestions, saying they were outside the scope of the consultation.
Out of the three that opposed, one was Channel 4, which had built a portfolio of free-to-air channels, among them Film4 which was made free-to-air on all platforms on 23 July 2006. Channel 4 argued that the number of free channels was the driving force behind the uptake of the platform, with more than 10 million Freeview boxes in use. A number of broadcasters requested that their replies were kept confidential. These include ITV and BSkyB. However, it is believed that ITV opposed the plan and BSkyB supported it.
The channels on Multiplexes B, C and D are those owned by the Freeview consortium and include the three Sky channels on the platform and the UKTV channels. However, Ofcom believed that in the short to medium term, it was unlikely free-to-air channels would convert to pay TV. This is because, firstly, Multiplex B is run by the BBC, which is not expected to request the removal of the free-to-air requirement. Secondly, due to the nature of the contracts the channel broadcasters held with multiplex operators and content providers, it was unlikely a channel would be able to change to pay-TV.
2008 BSkyB proposal