HDTV strategies

Cable broadcaster NTL has revealed that it started testing high-definition TV services using ADSL2+ technology last february. this can deliver high-speed data, currently at speeds of up to 18Mbits/sec, via standard telephone lines. At present the services to most homes that use ADSL operate at 1M/bits/sec.

Meanwhile BT is planning to offer TV services using IPTV (Internet Protocol TV) technology via its phone lines, and is developing technology that enables broadcasts with close to DVD quality to be delivered at 2Mbits/sec.

Satellite HDTV broadcaster Euro 1080 has announced that it will start using MPEG-4 this summer, when two new channels will be launched and its current channel HD1 will start to be encrypted. MPEG-2 will continue to be used for some transmissions until 2008.

BSkyB has released more information on its plans for HDTV. The service is to be launched next year. The HDTV set-top box will be a personal video recorder, like Sky+, and will be manufactured by Thompson. It was initially though that the set-top box would work only with TV sets that have a High Definition Multimedia Interface or Digital Video Interface that supports High Definition Content Protection. However BSkyB has informed Sony that, initially at least, the HDTV box will also interconnect with displays that have an analogue component-video input. BSkyB says that users with a display of screen size more than 26in and a HDMI socket will get the full benefit of the service. As a result of this decision, many who bought a flat-display TV without a HDMI or DVI input will be able to receive BSkyB's HDTV service.

Analogue switch-off trials

The first analogue switch off trials started on march 30th, when 360 homes in the welsh villages of Ferryside and Llansteffan, Camarthenshire, had their analogue TV signals switched off. Residents were provided with a DTT set-top box and PVR, along with technical assistance. Its estimated that the cost was about £350 per household. It has been suggested that, if re-elected the government plans to make a formal announcement about the analogue switch off this summer, and will adopt Ofcom's recommendation of a staggered switch off across the country. Ofcom is backing a change to the DTT transmission standard, from 2K to 8K OFDM. This relates to the number of carriers used in the orthogonal frequency-division multiplex. The proposal is backed by the manufacturers organisation Intellect ( BREMA), as it would improve the performance an enable a return to 64QAM modulation. But early IDTV sets and ITV Digital set-top boxes would be unable to decode the signals.