US engineers have combined light emitting diodes with powerline communication technology to give you domestic lighting with broadband access at the flick of a switch.

By combining LEDs with powerline communications, the engineer say they have created a data-transmission system for buildings that is faster than digital subscriber line (DSL) or cable and more secure than using radio frequencies.

The researchers at Penn State University used white LEDs to illuminate a room as uniformly as possible. Data delivered through the building’s electrical network can then be transmitted to wireless-enabled devices by ‘piggybacking’ on the light. Since light doesn’t penetrate walls in the same way that microwaves do, the white LED system is more secure than RF techniques, it is claimed.

Describing the technique at the IEEE Consumer Communications and Networking Conference in Las Vegas, Dr Mohsen Kavehrad of the University’s Centre for Information and Communications Technology Research claimed that it can deliver secure, wireless bit rates of a gigabit per second.

“In the future, when you turn on the lights for indoor low-cost lighting, you could receive broadband via the same white light LED,” said Kavehrad.

“Optical path differences can cause signal distortion in high-speed data transmission,” he added. “This distortion is highly dependent on the room's dimensions and system configuration. However, if a system is designed appropriately, this distortion can be minimised. For example, in our proposed system, at worst, distortion limits the data rate to one gigabit.”

Although white LEDs are not yet commercially available for this type of application, Kavehrad is confident that they will be by 2010 saying: “Their low-energy consumption will make them especially attractive.”