DTT Licences: SDN bid for B, C and D

Published Tuesday, Jun 18 2002, 14:23 BST | By James Welsh

SDN, the existing licence holder of multiplex A, is bidding for the rights to B, C and D.

The company is a consortium of S4C, United Business Media (UBM) and ntl. ntl:broadcast operates much of the UK's transmitter network.

SDN is proposing to carve up the role of multiplex operator and content provider, moving entirely away from the ITV Digital model - although in its bid it states it prefers the idea of 4 free-to-view multiplexes and 2 "lite" pay-TV ones where available.

In essence, SDN would become the technical manager for the multiplexes, and allow interested channel providers to apply for space on the multiplexes through a "fair" and "transparent" application process. Technical changes would be thus:

The transmission mode of all SDN multiplexes would be changed - as in the BBC/Crown Castle bid - to 16QAM 3/4
Each SDN mux would stream 18.1 mb/s; ntl compression tests using statistical multiplexing techniques state this would permit 5 channels per mux, 6 with "further development"

The model would be one of a "4+2" multiplex solution, with four nationally available DTT multiplexes providing free-to-view service from public service broadcasting, and two multiplexes providing a "lite" pay-TV service in certain regions where reliable reception could be guaranteed. Multiplex B would be set aside for further use by the public-service broadcasters to provide digital-only services.

SDN has set out a delivery timescale. After four weeks, all SDN multiplexes would be switched to the new transmission mode. Within 18 months, an equalisation programme would increase power to the maximum permitted at the existing 80 transmitter sites. After two years - although SDN says commercial concerns may delay this to 2006 - DTT would be rolled out to an overall total of 200 sites, massively increasing coverage.