Digital terrestrial television in the United Kingdom

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Digital terrestrial television in the United Kingdom is made up of over fifty primarily free-to-air television channels (including all the national analogue stations) and over twenty radio channels from Freeview, Top Up TV and Setanta Sports. It is intended that digital terrestrial television will completely replace analogue terrestrial television in the United Kingdom (and the Crown dependency of the Isle of Man) by 2012, and the Channel Islands by 2013. The Digital TV Group the industry association for digital television in the UK, is responsible for co-ordination between Freeview and other digital services. DTG licenses suitable equipment to bear the Digital Tick and Freeview Playback Logos [1] to identify PVRs and digital TV services designed to work through switchover, and to raise awareness of DTT product quality and standards. Digital terrestrial television is broadcast using the DVB-T international standard.

Receiving digital terrestrial television in the UK

To receive digital terrestrial television in the UK, a viewer needs a set-top box (prices start at around £10) or an integrated digital television (IDTV). Some set-top boxes are also personal video recorders, allowing viewers to record programmes from digital terrestrial television onto a hard disk.

All services apart from the Top Up TV channels are available free of charge to everyone with the ability to receive them (though not all services may be available to those with poor reception). The free channels are generally collectively referred to as Freeview, even though not all of them are technically part of the service.

Features

Digital terrestrial television provides many more channels than analogue television. For many viewers it offers a higher-quality picture (with many channels broadcasting in 16:9 anamorphic widescreen). A number of interactive services, including a newer version of Teletext, are also offered.

An eight-day Freeview (UK) electronic programme guide (EPG) allows viewers to see the names, descriptions and broadcast times for programmes. As this was not an original feature of digital terrestrial television when introduced in 2004, some receivers feature an EPG with details of the current and next programme only.

A fourteen-day Top Up TV EPG is an alternative which is transmitted by Channel Five, usually on Multiplex A. but on a different MUX in some areas. The service is available to TUTV's current proprietary model the Thomson DTI-6300 and older boxes such as the Digifusion series and an early Inverto DTR which supported the format formerly owned by 4TV. It is provided free-to-air and does not require a card or subscription.

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.[1]

The Independent Television Commission (ITC) allocated each existing analogue terrestrial channel half the capacity of a multiplex each. This meant the BBC got a multiplex to themselves (Multiplex 1), ITV and Channel 4 shared Multiplex 2 (though 3%[2] of the capacity was given to Teletext Ltd.) and Five and S4C shared Multiplex A. The remaining spectrum (Muliplexes B, C and D) was then auctioned off. A consortium made up of Granada and Carlton (members of the ITV network, which have now 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 made some use of its multiplex for three of its then four 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 (now both 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, would be paid for and were only available through an ONdigital subscription. Channel 4's nationwide coverage on 'mux' 2 enabled it 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' carries only Welsh-language programming, in contrast to S4C analogue which also carries English-language programmes commissioned and transmitted by Channel 4 in other parts of the UK.

Five sold its half of Multiplex A to the owners of the other half of the multiplex, S4C, who set up a subsidiary called S4C Digital Networks (SDN) to manage the multiplex and rented most of it out to ONdigital as well as 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 of Wales, preferring to sell the space instead. Consequently some ONdigital services were not available on Welsh transmitters.

While the BBC was 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.[3]

ITV Digital

ONdigital did badly from the start, and renaming the service ITV Digital on 11 July 2001 could not save it. 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, poor point-of-sale marketing [citation needed], no technical support for customers [citation needed], a recently cracked 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.

Freeview

As ITV Digital had collapsed, the rights reverted to the regulator and the ITC 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 ITV Digital failed 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 operates on Multiplex B. The BBC's second multiplex has 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 sporting events such as Wimbledon and carrying loops of news headlines and weather, (services already provided on digital satellite)

On 11 October 2005, ITV plc and Channel 4 joined the Freeview consortium and in the same year ITV plc also bought SDN and hence 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 2 rented by Top Up TV from Channel 4 and on multiplex A, rented from Five.[4] TCM purchased its own slot throughout England, Scotland and Northern Ireland from the multiplex owner, SDN, but rents from Sit-up Ltd in Wales, timesharing with bid tv. Multiplex A is ultimately owned by ITV Plc via its SDN acquisition, but ITV only has involvement with Top Up TV channels via Five.[4] In September of the same year, Top Up TV began operating solely on Multiplex A, as Channel 4 reclaimed the bandwidth on Multiplex 2 for its own services More 4, E4, and most recently Film4.

In October 2006, Five launched two new free-to-air digital channels, Five Life and Five US, using capacity leased out to Top Up TV.[5] This left Top Up TV with a reduced number of video streams. In November 2006, the company launched Top Up TV Anytime, a service which broadcasts overnight "downloads" which are recorded by a proprietary Top Up TV Anytime personal video recorder (PVR). At the same time, they started reducing the linear service.

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 may be lifted on Multiplex B, C and D. The effect of this ruling is that if a Mux operator requests the restriction to be lifted, their multiplex may carry pay TV services. Ofcom says that the digital television market has changed significantly since 2002. Consequently, it believes that this restriction is no longer required. Although Multiplex 2 and A have always been allowed to carry pay services, Ofcom believes that the free-to-air only restriction and the current state of DTT artificially damages the growth of pay tv on the platform [citation needed].

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 couldn't 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 changes the transmission mode of broadcast on all multiplexes from 16QAM to 64QAM so more services could be squeezed onto the digital terrestrial platform. 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 has been putting in place a portfolio of free-to-air channels, among them Film4 which was made free-to-air across all platforms on 23 July 2006. Channel 4 argued that the number of free channels available has been the major driving force behind the massive success of the platform – there are now 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.[6] In addition to replies from broadcasters, there were 21 replies from individuals. Of these, 20 opposed the change.

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 believes that in the short to medium term, it is unlikely existing free-to-air channels will 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 hold with multiplex operators and content providers, it is unlikely a channel will be able to change to pay TV.

It was announced on 8 February 2007 that BSkyB intended to withdraw Sky Three, Sky News and Sky Sports News from the platform in the summer of 2007. BSkyB had said that it intended to replace them with 4 of its subscription channels. It also said that it would use an alternative (MPEG4) codec, which would require new equipment for those who choose to receive the new service, and imply that the service will be unavailable to those with existing digital terrestrial equipment.[7] On 6 October 2007 Ofcom said that the plans for a new subscription service raised competition concerns and may have to be scrapped.[8]

2008 Update causing failures

During 2008, a rolling programme of transmitter updates caused approximately 250,000 set-top boxes to stop working altogether. Freeview had warned consumers in advance of the update, which was phased over a three-month period.[9] The problem affected a specific range of older units, and was caused by an increased Network Information Table (channel list) exceeding the memory available in some set-top boxes. This had been part of the specification that was available and implemented in the very early OnDigital boxes, but not in those using the SetPal chip set.[10] Affected consumers were advised to buy new set-top boxes.

Affected models are: Digital recorders: Bush IDVCR01 Daewoo DS608P

Digital boxes Daewoo SV900 Labgear DTT100 Portland DP100 Triax DVB2000T

Some other models and televisions also require an over-air download for correct operation.

List of digital terrestrial channels

Unless noted otherwise, channels may broadcast twenty-four hours a day (though not all use all of this available time).

Television channels

EPG No. Channel Notes Owner/parent company Broadcast hours Format Multiplex
1 BBC One Some regional variations in programming BBC 24 hours 16:9 SDTV 1
2 BBC Two Some regional variations in programming; variations from analogue in Wales and Northern Ireland BBC 24 hours 16:9 SDTV 1
3 ITV Uses various brands including 'ITV1', 'STV', and 'UTV', depending on regional station. ITV Network Limited
(consisting of ITV plc, STV Group plc, UTV Media, Channel Television Ltd, GMTV Ltd.)
24 hours 16:9 SDTV 2
4 Channel 4 Except Wales Channel 4 Television Corporation 24 hours 16:9 SDTV 2
4 S4C Digidol Wales only Welsh Fourth Channel Authority 24 hours 16:9 SDTV A2
5 Five RTL Group 24 hours 16:9 SDTV A2
6 ITV2 ITV plc 24 hours 16:9 SDTV 2
7 BBC Three Timeshares with CBBC Channel BBC 1900-0700 16:9 SDTV 1
8 Channel 4 Wales only Channel 4 Television Corporation 24 hours 16:9 SDTV 2
8 TeleG Scotland only; timeshares with CITV Channel, The Jewellery Channel, Nuts TV, Top Up TV Anytime 2 1800-1900 SDTV A
9 BBC Four Timeshares with CBeebies BBC 1900-0600 16:9 SDTV B
10 ITV3 ITV plc 24 hours 16:9 SDTV 2
11 Sky Three BSkyB 24 hours 16:9 SDTV C
12 UKTV History Timeshares with Virgin 1 UKTV (BBC Worldwide/Virgin Media Television) 0700-1800 16:9 SDTV D
13 Channel 4 +1 Channel 4 Television Corporation 24 hours 16:9 SDTV 2
14 More4 Channel 4 Television Corporation 24 hours 16:9 SDTV 2
16 QVC UK Timeshares with S4C2 in Wales QVC 24 hours (England, Scotland, NI)
24 hours (Wales) (Friday-Monday)
1700-0900 (Wales) (Tuesday-Thursday)
16:9 SDTV A
17 UKTV Gold Top Up TV; timeshares with British Eurosport, Teachers' TV, Top Up TV Anytime 3, UKTV Style UKTV (BBC Worldwide/Virgin Media Television) 1700-0100 16:9 SDTV A
18 4Music Box Television (Bauer Group/Channel 4) 24 hours 4:3 SDTV D
19 Dave Timeshares with SmileTV UKTV (BBC Worldwide/Virgin Media Television) 0700-0300 16:9 SDTV C
20 Virgin 1 Timeshares with UKTV History Virgin Media Television 1800-0600 16:9 SDTV D
21 TMF MTV Networks Europe 24 hours 4:3 SDTV D
22 Ideal World Ideal Shopping Direct plc 24 hours 4:3 SDTV D
23 bid tv Timeshares with The Jewellery Channel, Nuts TV, Top Up TV Anytime 2 in Wales sit-up Ltd/Virgin Media Television 24 hours (England, Scotland, NI)
0600-1800 (Wales)
16:9 SDTV A
24 price-drop tv sit-up Ltd/Virgin Media Television 24 hours 16:9 SDTV A
26 UKTV Style Top Up TV; timeshares with British Eurosport, Teachers' TV, Top Up TV Anytime 3, UKTV Gold UKTV (BBC Worldwide/Virgin Media Television) 1300-1600 16:9 SDTV A
28 ITV4 ITV plc 24 hours 16:9 SDTV 2
29 E4 Channel 4 Television Corporation 24 hours 16:9 SDTV 2
30 E4 +1 Channel 4 Television Corporation 24 hours 16:9 SDTV C
31 ITV2 +1 ITV plc 24 hours 16:9 SDTV D
32 Film4 Timeshares with Gems TV, National Lottery Xtra Channel 4 Television Corporation 1300-0400 16:9 SDTV D
33 British Eurosport Top Up TV; timeshares with Teachers' TV, Top Up TV Anytime 3, UKTV Gold, UKTV Style TF1 Group 0730-1030 4:3 SDTV A
34 Setanta Sports 1 Subscription service; timeshares with Top Up TV Anytime 1 Setanta Sports 1200-0300 16:9 SDTV A
35 Five US RTL Group 24 hours 16:9 SDTV A
36 Fiver Timeshares with Television X/Red Hot RTL Group 0600-2300 16:9 SDTV A
37 SmileTV Timeshares with Dave Cellcast Group 0300-0700 4:3 SDTV C
38 Top Up TV Anytime 1 Top Up TV; timeshares with Setanta Sports 1 Top Up TV 0300-1200 16:9 SDTV A
39 Top Up TV Anytime 2 Top Up TV; timeshares with bid tv (Wales), CITV Channel (England, Scotland, NI), The Jewellery Channel, Nuts TV, TeleG (Scotland) Top Up TV 0100-0600 16:9 SDTV A
40 Top Up TV Anytime 3 Top Up TV; timeshares with British Eurosport, Teachers' TV, UKTV Gold, UKTV Style Top Up TV 2330-0700, 1100-1300 16:9 SDTV A
41 Top Up TV Anytime 4 Top Up TV D 16:9 SDTV A
42 Nuts TV Timeshares with bid tv (Wales), CITV Channel (England, Scotland, NI), The Jewellery Channel, TeleG (Scotland), Top Up TV Anytime 2 IPC Media/Turner Broadcasting System Europe 2100-0100 16:9 SDTV A
43 Gems TV Timeshares with Film4, National Lottery Xtra 0945-1245 D
44 Gems TV 1 Timeshares with bid tv (Wales), CITV Channel (England, Scotland, NI), The Jewellery Channel, TeleG (Scotland), Top Up TV Anytime 2 1900-2100 16:9 SDTV A
45 National Lottery Xtra Timeshares with Film4, Gems TV National Lottery 0845-0945 SDTV D
46 SmileTV2 Cellcast Group 2100-? SDTV A
70 CBBC Channel Timeshares with BBC Three BBC 0700-1900 16:9 SDTV 1
71 CBeebies Timeshares with BBC Four BBC 0600-1900 16:9 SDTV B
75 CITV Channel Not available in Wales; timeshares with The Jewellery Channel, Nuts TV, TeleG (Scotland), Top Up TV Anytime 2 ITV plc 0600-1800 16:9 SDTV A
80 BBC News BBC 24 hours 16:9 SDTV 1
81 BBC Parliament BBC 24 hours 16:9 SDTV B
82 Sky News BSkyB 24 hours 16:9 SDTV C
83 Sky Sports News BSkyB 24 hours 4:3 SDTV C
86 S4C2 Wales only; timeshares with QVC UK S4C 0900-1700 (Tuesday-Thursday) 16:9 SDTV A2
87 Community Channel Timeshares with 302 Media Trust 0600-0900 4:3 SDTV B
88 Teachers' TV Timeshares with British Eurosport, Top Up TV Anytime 3, UKTV Gold, UKTV Style Education Digital Ltd/Education Digital Management Ltd 1600-1700 16:9 SDTV A
97 Television X / Red Hot / Fantasy / Viewers Wives Adult Northern and Shell (Red Hot) 2300-0400 4:3 SDTV A

^1 ITV1 is the brand name for 12 of the 15 regional ITV Network franchises for England, Wales, southern Scotland, the Isle of Man and the Channel Islands. Each of these 12 franchises has a separate brand name used prior to local programming, see ITV1. STV is the brand name for the franchises for central and northern Scotland. UTV operates the franchise for Northern Ireland. All 15 franchises broadcast 0925-0600; GMTV operates the franchise for national breakfast television and broadcasts 0600-0925.

^2 Five, S4C and S4C2 will move to a public service multiplex at the start of digital switchover, using the bandwidth created by switching from 16QAM to 64QAM mode, so will be transmitted from all 1,154[11] UK transmitters. None of the commercial multiplex operators have asked Ofcom to extend their multiplex to any of the 1,074 relay transmitters so these multiplexes will broadcast only from the existing 80 main transmitters that carry all the multiplexes after switchover.[12] Broadcast power for these multiplexes will, however, be increased, and they will use 64QAM mode, enlarging the national coverage from the current 73%[11] of the population to an estimated 90% by 2012.

Text and interactive services

EPG No. Channel Notes Owner/parent company Broadcast hours Format Multiplex
100 Teletext NHS Direct pages also available from split screen Teletext Ltd. Text service 2
101 Teletext Holidays Teletext Ltd. Text service A (Rest of UK)
2 (Wales)
102 Rabbit Teletext Ltd. Text service 2
103 Teletext Casino Teletext Ltd. Text service A
104 Teletext on 4 Teletext Ltd. Text service 2
105 BBCi BBC Text service 1
108 Sky Text BSkyB Text service C
300 4TVInteractive EPG service; compatible set-top-box required for full functionality (appears as blank screen) 0300-0400 Data service D
301 301 BBCi Video Stream; press the red button for full functionality BBC 24 hours 16:9 SDTV B
302 302 BBCi Video Stream; press the red button for full functionality BBC 0900-0600 16:9 SDTV B
303 303 Carries data for BBC News, BBC Parliament and CBeebies (appears as blank screen) BBC Data service B
304 tvtv digital EPG/recording service; compatible set-top-box required for full functionality (appears as a blank screen) Sony Data service C
305 305 Carries data for BBC News (appears as a blank screen, though with sound) BBC Data service B

Radio stations

EPG No. Channel Notes Owner/parent company Multiplex
700 BBC Radio 1 BBC B
701 BBC Radio 1Xtra BBC B
702 BBC Radio 2 BBC B
703 BBC Radio 3 BBC B
704 BBC Radio 4 FM version BBC B
705 BBC Radio 5 Live BBC B
706 BBC Radio 5 Live Sports Extra BBC B
707 BBC Radio 6 Music BBC B
708 BBC Radio 7 BBC B
709 BBC Asian Network BBC B
710 BBC World Service English language, European version BBC D
711 The Hits Radio Bauer Radio D
712 Smash Hits Not available in Wales Bauer Radio A
713 Kiss 100 Bauer Radio D
714 Heat Bauer Radio D
715 Magic 105.4 Bauer Radio D
716 Q Bauer Radio D
718 102.2 Smooth Radio Guardian Media Group D
719 BBC Radio Wales Wales only BBC 1
719 BBC Radio Scotland Scotland only BBC 1
719 BBC Radio Ulster Northern Ireland only BBC 1
720 BBC Radio Cymru Wales only BBC 1
720 BBC Radio nan Gàidheal Scotland only BBC 1
720 BBC Radio Foyle Northern Ireland only BBC 1
721 Mojo Not available in Wales Bauer Radio A
722 Kerrang! Bauer Radio D
723 talkSPORT UTV Radio C
724 Clyde 1 Bauer Radio C
725 Premier Christian Radio Premier Christian Media Trust C
726 U105 Northern Ireland only UTV Radio 2
727 Virgin Radio SMG plc C
728 Heart 106.2 Northern England, Southern England, Wales, Southern Scotland and the Isle of Man only Global Radio UK 2
728 100.7 Heart FM West Midlands only Global Radio UK 2
728 Heart 106 East Midlands only Global Radio UK 2

Technical details

The multiplexes

  • Multiplex 1
Operated by the BBC; broadcasts nationwide in 16QAM mode at 18 megabits/second
  • Multiplex 2
Operated by Digital 3&4 (an ITV/Channel 4 consortium); broadcasts nationwide in 64QAM mode at 24 megabits/second
  • Multiplex A
Operated by SDN (owned by ITV plc); broadcasts nationwide in 64QAM mode at 24 megabits/second
  • Multiplex B
Operated by the BBC; broadcasts nationwide in 16QAM mode at 18 megabits/second
  • Multiplex C
Operated by National Grid Wireless; broadcasts nationwide in 16QAM mode at 18 megabits/second
  • Multiplex D
Operated by National Grid Wireless; broadcasts nationwide in 16QAM mode at 18 megabits/second

* Pay TV service

Use of multiplexing technology

Each multiplex is an error-protected bitstream of 18 or 24 megabits per second, which can be used for almost any combination of digitally-encoded video, audio and data. The DVB-T standard provides a multiplex service that can make trade-offs between the number of services and the picture and audio quality.

  • a number of services use the same bandwidth at different times. For example CBeebies and BBC Four use the same space in Multiplex B, with CBeebies broadcasting from 6am until 7pm and BBC Four from 7pm; similarly for CBBC and BBC Three.
  • some multiplexes allocate more bandwidth to services, providing a smaller number of higher-quality services. For example BBC One on Multiplex 1 is carried as a 4.4 Megabit stream, while Sky Sports News typically uses 2 Megabits per second.
  • The modulation of the multiplexes can be varied to squeeze higher digital bitrates out of the same portion of the electromagnetic spectrum, but require a stronger signal for good reception. The modulation schemes used in the UK are, in order of bandwidth efficiency, each with a progressively higher bitrate, at the cost of progressively higher likelihood of signal degradation:
As of late 2007 multiplexes 2 and A use 64 QAM and are consequently more prone to poor reception, while the other multiplexes use 16 QAM. At switchover the transmission mode will change from 16QAM to 64QAM on Multiplexes 1 (PSB1) and B (PSB3)[13]. This will increase the effective bandwidth of each multiplex, and will allow Five, S4C and S4C2 to move to Multiplex B (PSB3). The switch to 64QAM mode will provide extra bandwidth on Multiplexes C (COM5) and D (COM6).
  • multiplexes can make use of statistical multiplexing at the MPEG video coder whereby the bitrate allocated to a channel within the multiplex can vary dynamically depending on how difficult it is to code the picture content at that precise time, and how much demand there is for bandwidth from other channels. In this way, complex pictures with much detail may demand a higher bitrate at one instant and this can result in the bitrate allocated to another channel in the same multiplex being reduced if the second channel is currently transmitting pictures which are easier to encode, with less fine detail. The only DTT channel which does not use statistical multiplexing, i.e. which uses a constant bit rate, is BBC One. This is so the English Regions and Nations can perform a simple transmultiplex, or T-Mux, operation and insert their local versions of BBC One over the London feed straight into the existing BBC Multiplex 1 without having to re-code the entire multiplex at each regional centre, requiring specialist (and costly) equipment at several locations.

New compression technology

Improved compression technology has allowed two additional television stations on the National Grid Wireless multiplex using the same bandwidth, with the possibility of more to follow on this and some other multiplexes.

This technique is only suitable for multiplexes that are identical nationwide. On Multiplex 1 where BBC One is one of 15 regional versions, BBC Two with four national variants (England, Scotland, NI and BBC 2W in Wales)[14], and Multiplex 2 with 19 ITV1 regions and six Channel 4 variations (used for advertising rather than programming) it is harder to increase the number of channels carried [citation needed].

The additional capacity has been achieved by developments in statistical multiplexing that allow the broadcaster to fit more channels into the same bandwidth. The two slots were auctioned earlier this year and, due to the limited capacity of the UK DTT, broadcasters bid high prices to gain bandwidth. ITV won the bidding for the first slot (on which it launched Men & Motors on 2 May 2005, replaced by ITV Play and later ITV2+1), and Channel 4 the second. Channel 4 launched E4 +1 (not its new channel More4) on the multiplex when the slot became available on 1 June (E4 launched on Freeview on 27 May 2005). National Grid Wireless have made a new slot available on Multiplex D using the new compression techniques. The 18 hour channel, running from 6am to midnight[citation needed], became available on 1 December 2005. Companies interested had until 1 November to submit their bids, with bids said to have reached £10 million, from an entry level of £5.5 million, with 12 separate bidders covering all sectors of broadcasting. This slot was won by Channel 4; it was occupied by More4+1 until live coverage of Big Brother replaced it on 18 May 2006. Film4 took over the slot 23 July 2006.

More recent compression technology, as now available in codecs like MPEG4, H.264 or Microsoft's WMV could enable a substantial increase in either quality or capacity due to their increased efficiency. For example, most existing programmes could be converted to high-definition with little or no increase in bandwidth[citation needed]. BSkyB have been the first to suggest such a move to increase the number of channels available within their own share of space using MPEG4 on a subscription service.[15] Any such change would obsolete all existing receivers, as new decoder set-top boxes or integrated digital televisions would be required (unless existing equipment could be reprogrammed, which is unlikely). BSkyB's proposals are pending approval by Ofcom, where these issues are likely to be a consideration.

The BBC, who would like to broadcast high-definition television on at least some Freeview channels, is considering an alternative method utilising spare capacity at night to allow the download of high definition programmes for later replay. The use of different codecs than those supported at present would not be a problem, as new equipment would be required anyway.

In addition the BBC’s Research and Development team have invented a transmission method that doubles the effective bandwidth that can currently be delivered by each multiplex using “spatial multiplexing”: 2 signals are sent on the same frequency in slightly different directions and at slightly different times. This will require new transmitters, aerials, and receiving equipment[citation needed].

Digital switchover

For full list of dates, see Digital switchover dates in the United Kingdom.

History

The progress towards digital switchover in the UK has been long. The then-Secretary of State for Culture, Media and Sport, Chris Smith, announced in 1999 that the Government's intention was to achieve switchover "between 2006 and 2010". Work started in earnest with the setting up of the Digital Action Plan, a body working across industry, government and consumer groups to advise on the best way to meet the switchover target date.

By 2003, however, it was becoming clear that switchover could not start by 2006. In particular, the decision taken by the International Telecommunication Union to call a Regional Radiocommunication Conference to establish a frequency plan for digital broadcasting meant that in practice, substantive steps towards switchover would need to wait until after the conference's second session, due to be held in May & June 2006.

On 15 September 2005, addressing the Royal Television Society in Cambridge, Smith's successor at the DCMS, Tessa Jowell, announced the go-ahead for switchover in the UK, coupled with support measures to ensure the disadvantaged are not left behind. [2]

In essence, the UK will switchover on a regional basis, starting in Whitehaven on the 17 October 2007, then the rest of the Border Television region in the second half of 2008, and then finishing in Channel Islands in 2013. Local television broadcasters, including the BBC and ITV, are actively encouraging viewers to upgrade to digital television. UK broadcasters are also under additional pressure to complete migration since London will be hosting the Olympic Games in 2012.

On the day after Jowell's speech, an independent. not-for-profit company, Digital UK, was established to coordinate the switchover process. Set up by the broadcasters and the commercial multiplex operators, Digital UK is required to co-ordinate the project and ensure that the public are kept informed about progress.

Digital rollout

File:New aerial after switchover.jpg
Areas covered by transmitters that will change frequency group and will require a new aerial to view TV after switchover (updated April 2007)
File:Three multiplexes after switchover.jpg
Areas where the strongest signal comes from a transmitter carrying only public service multiplexes after switchover
Ratio of homes with Freeview after switchover

The British Government has given Ofcom and Digital UK jointly the task of discontinuing analogue television broadcasting. The switchoff will occur on an ITV sub-region basis.[16] A technical trial in Ferryside, Wales, resulted in viewers voting to lose three out of the four available analogue channels in favour of going digital, so the unwanted analogue signals were switched off at the end of March 2005. In October 2007, following a 15-month publicity and information campaign, and an early digital launch in August by Five[17], the Whitehaven, Eskdale Green and Gosforth transmitters switched off analogue signals on the BBC Two frequency, and began broadcasting a temporary digital service for the main channels. On 14 November, all analogue signals were switched off, and the permanent three-multiplex digital service began (albeit with Five only on the Whitehaven transmitter, until 2009). Unfortunately, as had been feared, a small number of homes among the hills, which had received "fuzzy" analogue signals, particularly in Eskdale, were unable to receive a decodable Freeview signal.[18] The only other serious problem resulted from the "rescan" command in some models of set-top box defaulting to frequencies used by the nearest main transmitter, instead of the strongest digital signals; this could be overcome by using the "add channel" option to select channels one-by-one, and in the long term by corrections to the boxes' software.[19]

In November 2008 the full rolling programme will start with the Border Television Selkirk[20] region, then Caldbeck (which is being rebuilt, and will broadcast both England and Scotland multiplexes to improve service to viewers north of the border; the nearby Sandale transmitter will cease to broadcast TV), ITV Westcountry[21] Beacon Hill, Stockland Hill, Huntshaw Cross, Redruth, Caradon Hill, Wales[22] Preseli, Carmel, ITV Granada[23] whole region, Wales Llanddona, Moel-Y-Parc, Blaenplwyf, Long Mountain, Wenvoe then the rest of the UK: ITV West & STV North (Grampian Television): 2010; STV Central (Scottish Television): 2010-11; ITV Central, ITV Yorkshire and ITV Anglia: 2011; ITV Meridian, ITV London, ITV Tyne Tees & UTV: 2012; eventually finishing in the Channel Television region in 2013.[16]

Many decisions must be made, including what to do about people who may find the new technology confusing, or who have no desire to receive more than the four or five channels they presently have, and who may be reluctant to buy a digital box in order to view the free channels. The government has arranged for the BBC to administer a Digital Switchover Help Scheme to ensure that groups such as the over-75s and recipients of disability benefits will not lose their television services when analogue transmissions are switched off.

Another issue is that the "98.5 per cent of the population" availability target can only be achieved "via rooftop aerials",[24] while Section 134 of the Communications Act (2003) sets out the principle "that no person should unreasonably be denied access to an electronic communications network or to electronic communications services".[25] This is taken to mean that everyone has the right to mount a television aerial on their roof.[26] Ofcom will allocate frequencies for groups of households to provide "self-help" relay transmitters at their own expense (for analogue broadcasts there are some 200 of these, serving around 13,000 households), but suggests that in such cases, terrestrial TV may no longer be the most cost-effective solution.[27]

Landlords of communal housing are likely to have to upgrade old master aerial TV distribution systems. A new alternative, the integrated reception system is being promoted as a way to offer the full range of terrestrial and satellite broadcasts from a single aerial cluster; however, residents are likely to be asked to pay substantially higher annual charges when such a system is installed.

The switchover process

After several months of press publicity, leaflet drops, public meetings etc., captions will start appearing on analogue broadcasts from the affected transmitters, warning viewers that the analogue service will shortly be switched off and that they need to take action (for Whitehaven, the first large area to switch over, the captions started appearing some 5 months before the BBC Two analogue service was switched off[28]). At about the same time, details of the Switchover Help Scheme will be distributed. Although viewers who live outside existing Freeview reception areas will be unable to test any digital receiving equipment they buy at this early stage, test-screens on Ceefax (BBC One & Two) and Teletext (ITV & C4/S4C) page 284 make it possible to determine whether they are likely to need a new aerial or a signal amplifier to receive digital transmissions.

Next, detailed information booklets will be delivered to all households in the area (including many on the fringe who may be receiving their TV from other transmitters- hence the importance of the on-screen warning captions). Two or three months later, the analogue BBC Two signal will be replaced with Multiplex 1.[29] At the same time, captions will appear on the remaining analogue channels reminding viewers of the impending switchover. Finally, four weeks later, the remaining analogue transmissions will be switched off, with the analogue ITV signal being replaced with Multiplex 2, and the analogue BBC One signal with Multiplex B. At some locations, during the four-week switchover period, BBC One, ITV or Channel 4 will move to the analogue BBC Two frequency where that channel's frequency is required for the digital transmission of Multiplex 1.

Three multiplexes (current multiplexes 1, 2 and B) will be for public service broadcasting and contain around 25 TV channels, including all the television channels from the BBC, ITV (except ITV2+1), Channel 4 (except Film4 and E4+1), S4C and Five (except Five Life and Five US), half a dozen radio stations and half a dozen text/interactive services. The other three multiplexes (A, C and D) will continue to be operated by their respective commercial license-holders. To reflect the slightly changed roles, the multiplex names will change:[13]

Old multiplex name New multiplex name Owning company
1 BBC A BBC
2 D3&4 Digital 3&4
A SDN 'S4C Digital Networks' (ITV plc)
B BBC B BBC
C NGW A National Grid Wireless
D NGW B National Grid Wireless

Post-switchover

The adoption of the 8k format will be introduced at the final digital switchover date of 2012, unless it can be shown to Ofcom’s satisfaction that the impact of an earlier adoption would have minimal impact on viewers with 2k equipment. In those areas where single frequency operation will be required (covering the Meridian and Anglia regions) will adopt the 8k format when they are converted to all digital operation.[30]

Alternative post-switchover multiplex designations have been used on internal documentation by the BBC switchover contractor Arqiva,[31] however changing the designations of the multiplexes requires changes to legislation[1] and to the multiplex licences issued by Ofcom and is not in the current draft.[32]

When digital switchover is complete, two new sub-bands of the UHF spectrum will be clear (frequencies corresponding to channel ranges 31-40 and 62 to 69), leaving only channels 21-30 and 41-62 for digital television multiplexes. This "digital dividend"[33] will require millions of homes to upgrade their aerials to the wideband type to receive some or all of the Freeview multiplexes.[34] This spectrum is useful because of its tradeoff between bandwidth and range. The reallocated frequencies might be used for:

Reuse of this spectrum for other services will require legislation changes and international agreement. This is unlikely to be a significant problem as demand for spectrum is high throughout most of Europe. Ofcom currently plan to publish final proposals for this spectrum in mid-2007.[33]

Digit Al

Digit Al
Digit Al

Digit Al is a robot character created for Digital UK in 2005 by Abbott Mead Vickers BBDO and voiced by the English comedy actor Matt Lucas, used in material publicising the digital switchover. It will appear in the public information programme run by Digital UK until 2012. The character was first transmitted simultaneously on about 100 television channels and on regional BBC television on 5 May 2006.[35]

Future of Digital Terrestrial Broadcasting

In March 2006, the development of a new second generation Digital Terrestrial broadcasting standard, DVB-T2, was agreed by the DVB Group. It is expected that it will be finalised during 2008, ready for deployment in 2009.

The BBC, ITV, Channel 4 and Five have agreed with the regulator Ofcom to convert one UK multiplex (B, or PSB3) to DVB-T2 to increase capacity for HDTV (High Definition Television) via DTT[36]. They expect the first TV region to use the new standard will be Granada in November 2009 (with existing switched over regions being changed at the same time). It is expected that over time there will be enough DVB-T2 receivers sold to switch all DTT transmissions to DVB-T2, and MPEG-4 Part 10.

Ofcom recently published its final decision for HDTV using DVB-T2 and MPEG-4 [37]: BBC HD will have one HD slot after switch over and ITV, C4 and Five will compete for the two remaining HD slots from 2009 until 2012.

See also

References

  1. ^ a b "Broadcasting Act 1996". Office of Public Sector Information. Retrieved 2007-04-03.
  2. ^ "Digital 3 and 4 Ltd Response document (page 4)" (DOC). Ofcom. Retrieved 2007-04-26.
  3. ^ "A comprehensive guide to Digital Broadcasting". Published Papers. BBC Research. Retrieved 2007-04-03.
  4. ^ a b "ITV plc acquires SDN Limited" (Press release). ITV plc. 27 April 2005. Retrieved 2007-04-03.
  5. ^ "five unveils two new channels" (Press release). five.tv. 5 June 2006. Retrieved 2007-04-03.
  6. ^ Chris Tryhorn (19 April 2006). "Broadcasters get green light for more pay-TV". Guardian Unlimited. Retrieved 2007-04-03.
  7. ^ "Sky's top shows to go terrestrial". BBC News. 8 February 2007. Retrieved 2007-04-03.
  8. ^ Richard Wray (5 October 2007). "Fresh rebuff for BSkyB over Freeview pay-TV". Guardian Unlimited. Retrieved 2007-10-18.
  9. ^ Sweney, Mark (2008-08-14). "Freeview upgrade leaves set-top boxes obsolete". The Guardian. Retrieved 2008-08-25.
  10. ^ "Freeview boxes destined for landfill". FrequencyCast. Retrieved 2008-08-25.
  11. ^ a b "Switchover–related Changes to DTT Licences" (PDF). Ofcom. 19 July 2006. Retrieved 2007-10-18.
  12. ^ "Ofcom sets Digital Switchover related licence conditions" (Press release). Ofcom. 7 December 2006. Retrieved 2007-04-03.
  13. ^ a b "Digital Switchover Transmitter Details: Border Region" (PDF). Ofcom. Retrieved 2007-04-06.
  14. ^ "Which BBC regions are on satellite? - ukfree.tv - get free UK television". Retrieved 2007-04-03.
  15. ^ "Freeview to lose Sky channels". Telegraph.co.uk. 9 February 2007. Retrieved 2007-10-18.
  16. ^ a b http://www.digitaluk.co.uk/en/news-media/pressReleases/019/file/DigitalUK161006.pdf
  17. ^ Whitehaven News article on Five digital launch, 6 September 2007
  18. ^ North-West Evening Mail article on Eskdale reception problems, 14 November 2007
  19. ^ Whitehaven area experiences of switchover problems
  20. ^ http://www.digitaluk.co.uk/en/when/border/resources/0/file/border.pdf
  21. ^ http://www.digitaluk.co.uk/en/when/west-country/resources/0/file/west_country.pdf
  22. ^ http://www.digitaluk.co.uk/en/when/wales/resources/0/file/wales_english.pdf
  23. ^ http://www.digitaluk.co.uk/en/when/granada/resources/0/file/granada.pdf
  24. ^ "BBC and Arqiva take major step towards Digital Switch Over" (Press release). BBC. 18 September 2006. Retrieved 2007-04-03.
  25. ^ "Communications Act 2003". Office of Public Sector Information. Retrieved 2007-04-03.
  26. ^ "Digital switchover: an audit of viewers' priorities, §6.31" (PDF). Ofcom. 12 July 2006. Retrieved 2007-10-18.
  27. ^ Self help TV relays and digital switchover Ofcom consultation document
  28. ^ "Countdown to UK's first switch begins" (PDF) (Press release). Digital UK. 15 March 2007. Retrieved 2007-04-25.
  29. ^ "BBC Two first to go fully digital". BBC News. 9 November 2005. Retrieved 2007-04-03.
  30. ^ "Planning Options for Digital Switchover : Statement". Ofcom. Retrieved 2007-10-18.
  31. ^ http://www.arqiva.com/upload/pdf/PROVISION_OF_NETWORK_ACCESS.pdf
  32. ^ "Switchover related Changes to DTT Licences". Ofcom. Retrieved 2007-04-03.
  33. ^ a b "The Ofcom Digital Dividend Review (DDR)". Ofcom. Retrieved 2007-04-03.
  34. ^ "House of Lords - BBC Charter Review - Second Report". Retrieved 2007-04-03.
  35. ^ "Little Britain star goes digital". BBC News. 4 May 2006. Retrieved 2006-05-04.
  36. ^ "3 Freeview HD channels will start 2009 – ukfree.tv – independent digital television and switchover advice, since 2002". Retrieved 2007-11-25.
  37. ^ "Ofcom Statement on DTT future, announced on April 3, 2008". Retrieved 2008-04-09.

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