BT has unveiled plans to launch two major pilot schemes for so-called next-generation broadband in London's Muswell Hill and Whitchurch in South Glamorgan.

Up to 15,000 businesses and consumers in the two areas will take part in the trial, which should allow them to access internet connection speeds of 40 megabits a second.

The scheme involves the use of fibre-optic cables to transmit data rather than conventional phone lines. These will be installed from telephone exchanges to street cabinets as part of the project.

The company said the two locations had been chosen because of the combination of existing internet providers and the mix of customers, as well as the current communications network.

A smaller pilot will run in early 2009 with just 30 homes connected to the Foxhall exchange in Kesgrave in Suffolk.

The main pilots will commence in Summer 2009.