Ofcom to use free airwaves for rural broadband

White space technology works in the spectrum gaps

Ofcom is considering using the airwaves freed up when FM radio goes digital to provide rural broadband.

So-called white spaces devices are currently being trialled for use in the spectrum gaps freed up by the digital TV switchover.

Ofcom believes they would work equally well in the FM spectrum.

There is no set date for the switchover from FM to digital radio although the government is keen for it to happen in 2015.

Some think that date is unrealistic due to the slow take-up of digital radio and the current lack of coverage.

White space technologies have been gathering momentum in recent months. They take advantage of spare spectrum bands that have not been licensed for any other use. This makes them attractive to communications firms because they get to use for free what would otherwise be extremely expensive.

That makes the technology particularly useful for providing rural broadband where the costs of laying cables or otherwise supplying bandwidth are much higher.

The technology works by identifying the unoccupied white spaces to transmit and receive wireless signals.

Compared with other forms of wireless technology, such as Bluetooth and wi-fi, white space devices are being designed to use a much wider range of frequencies, including the lower frequencies that have traditionally been reserved for TV and radio.

Low frequencies work better in buildings, something that has been a problem for higher frequency 3G technologies.

Other possible uses for the technology include offering a link between devices, so that more objects can be connected to the network.

Ofcom's chief executive Ed Richards said: "Spectrum is a resource that is in huge demand, fuelled by the recent explosion in smart phones and other wireless technologies.

However, there is only a limited amount of it to go around, which means we need to start thinking more creatively about how it is used. White space devices could offer the creative solution we are looking for."

BT is currently testing white space technology on the Scottish island of Bute and said early results were "promising".

Last month Microsoft, the BBC, BT and Nokia announced they would launch a white spaces consortium.

Cambridge start-up Neul is leading the way in making white-space equipment. It estimates that there is around 150MHz of unused spectrum in the UK, which is five times as much as Vodafone has for its 3G services.

The technology offers speeds of around 16 megabits per second but has the potential to be much faster.

To avoid interference, equipment needs to pass very stringent tests.

"If Ofcom decides to free up this spectrum we'd definitely consider using it," said Luke D'Arcy, vice president of marketing at Neul.