FIFTH TV CHANNEL: STUDY (Hansard, 28 July 1988)

§ Lord Young of Graffham

On 14th October last year the Government announced their decision to commission a technical feasibility study into the possibility of a fifth terrestrial television service using the UHF bands IV and V in which existing television service operate. The study was carried out by an interdepartmental steering group of officials, which also included the active participation of the BBC, the IBA and the Civil Aviation Authority, whose help I gratefully acknowledge.

The study concluded that a fifth channel covering 65 to 70 per cent. of UK households should, subject to the considerations detailed below, be possible from about 1992 using frequences in UHF Band V.

UHF bands IV and V cover the 44 channels currently used to provide four television services to more than 99 per cent. of the population. Band V also includes four channels, 35 to 38, which are currently used in the UK for other purposes. The study covered a number of possible approaches. Of these, the most favourable involved the use of Channel 35 (currently 478WA allocated for programme-making activities and theatre radio microphones) and Channel 37 (currently used, together with Channel 36, by aeronautical radar). Subject to international agreement and the satisfactory relocation of existing users, these two channels, 35 and 37, could be used to provide a national network, or series of regional networks, covering 65 to 70 per cent. of UK households. They could probably be made available from the beginning of 1992, though these decisions do not turn only on technical matters.

The study identified a number of costs and some uncertainties. The costs would include the re-equipment costs of moving existing users to alternative spectrum. Thus aeronautical radars in Channel 37 would need to move to Channel 36 some two years earlier than would otherwise have been the case. Some radars would need to be retuned within Channel 36 and also fitted with additional filtering, to avoid interference to and from broadcasting in the adjacent Channels 35 and 37. Certain radio-astronomy installations operating in Channel 38 would need additional filtering to protect them against interference from television transmissions in Channel 37.

There would also be the costs of moving services ancillary to broadcasting and some theatre radio microphones from Channel 35. There would be difficulties in finding an equally satisfactory alternative spectrum for these users. Creating an additional television network will bring with it increased demands for programme-making activities which it will be more difficult to satisfy if the spectrum available to the programme-makers is reduced.

Most video recorders and some home computers use Channels 35, 36 or 37 to communicate with the television receiver. They would be prone to cause (or suffer) interference to (or from) television broadcasts in the same or an adjacent channel. Interference might extend to neighbouring premises, and could also affect viewers who had chosen not to receive the new service. To avoid this, many video recorders and some home computers within the coverage area of the new broadcast service would need to be retuned. This would involve costs for those householders who were not able to carry out the retuning themselves. Because a new service would in most cases be transmitted using a different polarisation or be in a different part of the band from that used by existing television services, a significant number of households wishing to receive the new service would need either a new UHF aerial or a second aerial together with a mixing circuit. The average installed cost per household might amount to £30 to £50.

The new transmitters and the new arrangements for aeronautical radars would need to be negotiated in detail with neighbouring administrations, and we have already registered with the International Frequency Registration Board our interest in introducing a fifth television network using Channels 35 and 37.

An alternative approach examined was to make a more intensive use of the 44 channels currently used for broadcasting. The study found that without 479WA removing one or more existing service from a small proportion of viewers, and within the planning constraints imposed by the limited standards of immunity achieved by most existing television receivers, the coverage that could be achieved by this means was significantly less than 20 per cent. of UK households. Because this coverage was almost wholly within areas that could be covered by a service on Channels 35 and 37, this approach could not be used to supplement to any worthwhile extent the Channel 35 and 37 coverage.

A more intensive use of the 44 current broadcasting channels might, however, play a part in the provision of a sixth UHF network. Although the group's terms of reference did not include the feasibility of a sixth UHF network, they concluded that such a network covering over 50 per cent. of the population should not be ruled out as a possibility in the slightly longer term, though its cost could be significantly greater. Further study would be needed to identify this possibility with greater precision. It would depend on securing access to one or more of Channels 36, 38 and 69, all of which are currently used for other purposes and may also be crucial to accommodate users displaced from Channels 35 and 37. It is possible that benefits in coverage could be obtained if the fifth and sixth services were planned together using all the available channels, although they could thereafter be implemented over different timescales. Nevertheless this would probably delay the introduction of the fifth service beyond 1992.

The Government will not reach decisions on the introduction of additional fifth television services without the most careful consideration of all the implications; and, if they decide to introduce the fifth channel,, will seek to discuss the implications with those most closely affected.