Data-over-mains looks good

Data-0ver-mains looks good

Data-over-the-mains trials in Scotland have been successful and could lead to fast Internet access in many places where it is currently not available, the company running them says.

Southern Electric, part of the Scottish and Southern Energy Group, has formally opened 'a marketing pilot' in Winchester to see what the take-up will be in an area already served by both ADSL and cable services.

These typically offer download speeds of 500Kbits/sec for entry-level services, with uploads at a maximum 250Kbits/sec. The new Southern Electric service costs £29.99 a month, slightly more than basic consumer broadband, but it provides speeds of 1Mbit/sec in both directions. Details can be found here

Upload speeds are an issue mostly for illicit file swappers, gamers, and businesses with a lot of traffic in both directions; but they will become more important with the increasing use of applications such as remote video surveillance, voice-over-IP and videophones.

The new system is similar to ADSL, in that it piggybacks a high-frequency signal onto lines designed for low-frequencies, though it uses the AC mains instead of phone lines. For connection, you simply plug a special modem into any socket in your home.

It requires equipment to be installed at electrical substations, but this can done if there are only 50 people wishing to subscribe.

'That can be reduced to one or two if there is a big user like a business or school in the area,' said Southern Electric?s director of telecoms, Keith Maclean.

He said the major cost was in the 'back haul', the link between the substation and the Internet backbone, and this varied according to the method. In some remote areas it was done by satellite, which is a running rather than a capital cost.