Just a week after a Cambridge-based consortium announced plans to trial so-called white space broadcasting, Ofcom says it’s identified some suitable spectrum.
Chief executive Ed Richards says that as the UK moves to digital radio, there’s plenty of FM frequencies being freed up.
While white space efforts so far have tended to focus on the free spectrum between digital TV channels, he says, “We believe that any release of new spectrum has great potential to enable innovation and growth in new applications and services.”
A recent report from telecom analysts Plum Consulting concluded that allowing unused radio wave spectrum - of any frequency - to be used for mobile broadband would boost Europe’s economy by €54 billion over the next ten years.
FM radio currently occupies the band between 88 and 108MHz.
The switch to digital radio is expected to free up around half of this spectrum - although there’s still no definite date by which this will happen.
The government’s keen for it to happen by 2015, but it could take much longer than that. Some smaller stations are likely to remain analogue indefinitely.
“Our first principle has to be that any future use of the FM band is an efficient use of radio spectrum,” says Richards.
“There must be certainty for smaller and community stations, that do not move across to DAB. These will continue to play their important role, and FM is an appropriate technology for the scale at which they operate.”
He says the idea could even work to the benefit of radio stations by making sure that the spare frequency doesn’t fill up with pirate stations or competing commercial stations.
The big problem is keeping track of what white space is free in different areas, in order to avoid interference. The only practical way to do this, says Ofcom, is to keep geolocation databases containing live information about which frequencies are free to use at any current location.
The white space router or base station would access the database and describe its location to receive details of the frequencies and power levels that won’t interfere with other devices operating nearby. Ofcom says it plans to make it possible for interested companies to host such databases.
The regulator plans to release its thoughts on TV white space usage soon.