BT’s broadband arm, Ignite, has announced the trial of its SDSL (Symmetric Digital Subscriber Line) service, which will run from December until June 2001.

SDSL is another flavour of ADSL (Asymmetric Digital Subscriber Line. Like ADSL, SDSL runs over the normal copper wires used for the telephony network.

The key difference is that with ADSL, most of the bandwidth channel is used to send data downstream to the customer and a small part to return information – BT’s initial ADSL service offered 512Kbps downstream and 256Kbps upstream.

SDSL uses both channels equally. The maximum speed promised by Ignite’s service is 1.9Mbps in both directions.

This will allow businesses to use the upward stream for communication with other offices, data transfer, web hosting, videoconferencing and in the future it will allow a company’s telephony service to be run over it with voice over DSL (voDSL).

Ignite has opened the trial service to ISPs, corporates and other telecoms, which are expected to in turn offer it to end users. The full service is expected to launch next summer.

However the service won’t come cheap. The initial pricing for the trial service is £110 for connection and then for a 500Kbps line £342 per year; a 1Mbps line, £400 and a 1.9Mbps line will cost £497 per year.