ITC consults on options for change in DTT transmission

9th August 2002

The ITC is today (Friday 8 August) inviting comments on options for change in the transmission mode for digital terrestrial television (DTT).

Since DTT services were launched in 1998, it has become clear that reception difficulties have hindered their uptake for some viewers. There are several reasons for this, including the need to limit the power of the transmissions to avoid causing interference to reception of existing television services; and the poor performance of significant numbers of receiving installations, many of which have deteriorated over the years. While in some areas it has been possible to boost transmitter powers and change to more favourable frequencies in order to improve coverage, further measures are desirable to make it easier to receive DTT services using existing aerials.

In their recent applications for Multiplex Service Licences B, C and D, five of the six applicants, including all the existing multiplex operators, proposed a change to a '16QAM' transmission mode. This would have a beneficial effect on reception equivalent to more than doubling the powers of the transmitters, thereby over-riding many reception problems. However, a consequence of the change of transmission mode would be that fewer television services could be transmitted. This has already been taken into account in the plans of the successful applicants, BBC and Crown Castle, who between them will operate four of the six DTT multiplexes.

The ITC recognises that there would be clear advantages for viewers in applying the transmission mode change in a consistent way to all multiplexes, and anticipates that the improved ease of reception would lead to a strengthening of confidence among consumers and industry. While the other two existing multiplex operators have also recognised these benefits of the proposed transmission mode change, they would need to review the number of services they currently offer, and any other implications.

The ITC is therefore seeking views on two options: the first, that all multiplex operators be required to adopt the new 16QAM transmission mode; the second, that individual multiplex operators be allowed to choose whether to adopt the new transmission mode with its associated benefits for reception, or whether to maintain the current 64QAM transmission mode. The ITC wishes in particular to take account of views as to which option would best promote the development of digital terrestrial television broadcasting in the UK.

Comments on the issues raised in this consultation are invited by 12 September 2002 and the ITC will announce the outcome before the end of September 2002. The ITC is proposing that the change of transmission mode should take effect from 1 October 2002.