BBC signs deal to upgrade digital TV network

27th September 2006

Quoting from the Radio Netherlands Media Network Blog:

"The BBC and Arqiva have concluded contract negotiations for the design, deployment, and operation of its new high-power digital terrestrial television (DTT) network which will replace both the BBC’s analogue television networks and the current low-power DTT network. Arqiva will also build and operate additional transmitters to expand the coverage of the BBC’s DAB digital radio network, with the possibility of up to a further 160 new DAB transmitters being ordered in the coming years. The deal is expected to be worth, taking into account inflation, in excess of £1.8bn over the contract period."

Currently, DTT transmitters are running at low power so that they don't interfere with analogue TV transmissions, and once analogue TV is switched off, which will happen on a region-by-region basis starting from 2007/8, the DTT transmitters can be increased. This increase in transmission power will allow the BBC DTT multiplex capacities to be increased from the current 18.1 Mbps to 24 Mbps, by changing the modulation order from 16-QAM to 64-QAM.

The BBC has two DTT multiplexes, so increasing them both from 18 to 24 Mbps will provide approximately an additional 12 Mbps of capacity. Unfortunately, that would only allow the launch of one new HDTV channel, so the BBC is lobbying government to try and get its hands on some of the spectrum that will be freed up once analogue TV has been switched off.

Another possibility to provide extra terrestrial capacity is that a new DVB-T2 system is designed to replace the current DVB-T standard — in the same way that the new DVB-S2 satellite system, which the new HDTV channels from the BBC and Sky are using. I'll write more about DVB-T2 in a future article.