Analogue television in the United Kingdom

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Before 2006, analogue transmissions were the most used method of receiving television in the United Kingdom. It is expected that terrestrial analogue transmission will cease by 2012 with a phased transition to digital terrestrial television (based on the DVB-T standard and generally known in the UK under the brand name "Freeview") occurring on a regional basis from 2008.

Contents

[edit] Major networks

The major networks are transmitted nationally, and are currently have signifficantly greater coverage than than digital broadcasts, though this is expected to change after switchover. BBCs 1-2 and Channels 3-4 can be received in 99% of homes, whereas Channel 5, can be received in just over 70%.

  • BBC One - Public service network funded by a yearly mandatory licence fee. Includes regional variations.
  • BBC Two - Public service network funded by a yearly mandatory licence fee. Includes a few regional variations, mostly outside of England.
  • Channel 3 - Nominally public service, commercial network operating as ITV1 in England and Wales, STV in Scotland, UTV in Northern Ireland and GMTV for the first few hours of each day. Includes regional variations.
  • Channel 4 - Commercially funded, public-service network (not broadcast in Wales). Includes no regional variations, except for the sake of advertising.
  • S4C - Commercially funded public-service network only available in Wales; 50% of programming in Welsh. Includes no regional variations.
  • Channel 5 - Mainly commercial network, with some minor public-service obligations, operates under the name Five. Includes no regional variations, except for the sake of advertising.

[edit] Regional Variations

Both BBC One and Channel 3 have small regional variations throughout England, alongside single variations in Wales, Northern Ireland and Scotland (however the ITV Network legally has two variations in Scotland whereas the BBC have one), and generally use these variations to broadcast programming specific to the region. BBC Two previously also followed the same system, but have since been phased out leaving four variations of Scotland, Northern Ireland and Wales alongside the English network. Channel 4 and Five have regional variations only for the sake of advertising whilst S4C contains no variations whatsoever.

[edit] Restricted service licence

In addition to the 5 national networks, a limited number of local stations are broadcast to various towns and cities under what is known as a Restricted Service Licence. These occupy channels unused by the other broadcasters that can be used without causing interference in other regions, and are frequently broadcast at a lower power than the major channels. Their output is mainly local, and each contract for an RSL lasted four years until 2004 when media regulator Ofcom stated that each licence will be renewed up until digital switchover.

Some licences are not currently in use:

[edit] 405 Lined System

System A 405 lines on Band I (Ch 1-5) and Band III (6-13)
Ch Video (MHz) Audio (MHz)
1 45.00 41.50
2 51.75 48.25
3 56.75 53.25
4 61.75 58.25
5 66.75 63.25
6 179.75 176.25
7 184.75 181.25
8 189.75 186.25
9 194.75 191.25
10 199.75 196.25
11 204.75 201.25
12 209.75 206.25
13 214.75 211.25

Television broadcasting began on an experimental basis by the BBC in London in 1936 on VHF Band I. Initially the service was operated using two competing systems:

The earliest television broadcasts used the 240-line Baird system and the 405-line Marconi-EMI system on alternate weeks. However, the Baird system proved too cumbersome and by early 1937 had been dropped and the Marconi-EMI system became the standard. This system was later codified by the ITU's CCIR on an international conference in Stockholm in 1961 as System A.

Different broadcast stations across the country broadcast on different channels to avoid interference and allow for regional variations.

Broadcast was suspended during the Second World War but resumed in 1946. The BBC was joined on this system in 1955 with the launch of commercial television in the form of the regional Independent Television (ITV) network, managed by the Independent Television Authority (ITA), which also saw the use of VHF Band III.

This was the sole system in existence until the preparations for the introduction of 625-line transmission in 1964 and was put out of use in 1985.

[edit] 625 Lined System

System I 625 lines (Bands IV and V)
*not in use until later date
Ch Video (MHz) Audio (MHz)
21 471.25 477.25
22 479.25 485.25
23 487.25 493.25
24 495.25 501.25
25 503.25 509.25
26 511.25 517.25
27 519.25 525.25
28 527.25 533.25
29 535.25 541.25
30 543.25 549.25
31 551.25 557.25
32 559.25 565.25
33 567.25 573.25
34 575.25 581.25
35* 583.25 589.25
36* 591.25 597.25
37* 599.25 605.25
38* 607.25 613.25
39 615.25 621.25
40 623.25 629.25
41 631.25 637.25
42 639.25 645.25
43 647.25 653.25
44 655.25 661.25
45 663.25 669.25
46 671.25 677.25
47 679.25 685.25
48 687.25 693.25
49 695.25 701.25
50 703.25 709.25
51 711.25 717.25
52 719.25 725.25
53 727.25 733.25
54 735.25 741.25
55 743.25 749.25
56 751.25 757.25
57 759.25 765.25
58 767.25 773.25
59 775.25 781.25
60 783.25 789.25
61 791.25 797.25
62 799.25 805.25
63 807.25 813.25
64 815.25 821.25
65 823.25 829.25
66 831.25 837.25
67 839.25 845.25
68 847.25 853.25

1964 saw the launch of a third television service, known as BBC2, and with it the introduction of the analogue system of broadcast still used to this day - the 625 lined service on UHF Bands IV and V. Whilst the extra lines theoretically offered better resolution and picture clarity, the fledgling network of new transmitters required to provide the service offered far inferior coverage compared with the existing VHF services and was prone to increased interference often resulting in poor picture quality. Furthermore, few people had the new sets required to receive the new service or the different type of aerial required to pick up the UHF signal.

[edit] Colour

During the late 1950s, when the decision to introduce colour television was first seriously mooted, the then two main systems for consideration were the French SECAM and American NTSC systems, the latter generally considered superior and expected to be adopted. Throughout the 1960s a third competing system, PAL, became available and was eventually adopted by the GPO for use on the 625 lined service, to be known as System I or PAL-I.

Broadcast on this system officially commenced in 1967 with BBC2's (and the UK's) launch of colour television programming, though previous years had seen many unofficial colour test films outside of official broadcasting hours, including some which trialed NTSC and SECAM. BBC2 was joined in 1969 by BBC 1 and the main ITV franchises (the rest following in stages into the 1970s). Both BBC1 and ITV continued to broadcast simultaneously on the VHF system A until 1985.

[edit] Channel allocations

The 625 lined system divided the spectrum into 44 channels, 21-34 and 39-68 (Bands IV and V). These channels were allocated, by the GPO, to the broadcasters to allow for four networks to operate with eventual maximum coverage and minimum cross-network interference. The two BBC channels and the ITV network were catered for, as well as space for a future forth network, at the time expected to be a second network for the ITA. The forth network didn't come into being until the 1980 Broadcasting Act created Channel 4 and S4C. This early provision meant that near complete coverage was afforded to both networks at launch, in 1982.

When Channel 5 launched in 1997 a general lack of provision for the network lead to the release of extra UHF channels which caused potential interference with many domestic VCRs. This required a massive equipment retuning exercise to be undertaken at the broadcaster's expense. The extra channels still did not go far enough in affording Channel 5 the level of coverage enjoyed by the other broadcasters.

[edit] Digital Switch-over

The government is committed to switching terrestrial television broadcasting to completely digital by 2012. A company called Digital UK (formerly "switchco") has been set up to handle the change. The switch will be on a region by region basis using the ITV regions as a basis. The schedule was announced by Secretary of State for Culture, Media and Sport, Tessa Jowell on September 15, 2005 at the Royal Television Society Cambridge Convention.

Regional Order TV Region Proposed Date
1st Border 2008 (second half)
2nd Westcountry 2009 (first half)
3rd HTV Wales 2009 (second half)
4th Granada 2009 (second half)
5th HTV West 2010 (first half)
6th Grampian Television 2010 (first half)
7th Scottish Television 2010 (second half))
8th Central 2011 (first half)
9th Yorkshire 2011 (first half)
10th Anglia 2011 (first half)
11th Meridian 2011 (first half)
12th Carlton/LWT 2012 (first half)
13th Tyne Tees 2012 (first half)
14th UTV 2012 (second half)

No date was announced for the 15th ITV region, Channel Television, as this broadcasts from the Channel Islands, outside the jurisdiction of the UK Government. Under the original proposals it would convert last, after UTV.

Some concern has been raised that the London region will be switched shortly before the city hosts the Olympic Games. Jowell said "I can assure you that I did not slog for two years to bring the games here just to see Londoners reduced to huddling round the wireless to find out who won the hundred metres, I am completely confident that our timetable is a sensible one which will ensure that digital services are delivered with no disruption to the viewing public during the Games themselves."

It was also announced that a support scheme will be put in place to ensure that no one is left behind in the switch. It will provide help with equipment and installation and follow-up support for people aged 75 years and over and people with significant disabilities. The scheme will be funded by the BBC through the licence fee. Help will be free for the most needy, with a small change levied for others

[edit] Use on satellite and cable systems

Initially satellite and cable systems broadcast using standard (PAL) signals though often scrambled to prevent people watching the channels without paying a subscription.

The major provider of satellite television in the UK, BSkyB launched a digital service (called Sky Digital) in 1998 based on DVB-S. This allowed many more channels and was marketed with a smaller dish. Take-up was very successful and Sky discontinued the former analogue service in 2001, although some of the channels which had been part of their package, such as CNN and CNBC Europe, have continued broadcasting unaffected by Sky's departure

Cable has not fully transitioned to the digital format (DVB-C) as some parts of the physical cable network are not suitable for transmitting the digital signals. It is not known when (if ever) analogue transmission will cease on these systems. In some parts of the network where digital cable is available, analogue transmissions have been ceased in order that the bandwidth may be utilised for more data for the digital platform, in others both systems run alongside each other, though often new channels will launch on digital at the expense of channels on the older analogue network, which encourages those users to switch.

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