Tight White Spaces to be penetrated in Blighty this year - Ofcom

White Space networking kit will get large-scale trials later this year, to see if multiple databases and radio protocols can be deployed without knocking TV off the air.

Ofcom hasn't decided who'll take part in the trials, or what parts of the country they'll cover, or even how long they'll last, but they will run this autumn and will pave the way for unlicensed use of White Space in the TV bands early next year.

White Space kit uses radio frequencies unoccupied in the surrounding area - but they may be in use elsewhere. Devices are required to check with a database for frequencies available at its current location. They submit their GPS coordinates and the radio protocol they plan to use, and receive details of a maximum permitted power and duty cycle (how much time they can transmit) to avoid interfering with Freeview TV signals.

Companies hoping to profit from White Space have already run extensive trials around the UK - the Cambridge trials, for example, used databases from Spectrum Bridge and Microsoft - but this time they'll all come together using Ofcom's website to direct devices to the right database, checking it all works properly.

It seems probable that it will: in the US the TV White Spaces are already filling up with unlicensed users enjoying the unprecedented range and penetration of the TV bands - and without significant interference to viewers.

Spectrum Bridge, which got the first US approval and has every intention of getting Ofcom approval too, told us last year that the UK market is rather different from the US in ways which are both good and bad.

Here in Blighty we have an effective monopoly broadcaster in the form of Arqiva, which owns the transmission sites for most of the UK's broadcast networks. Arqiva has enormously detailed radio maps of the UK, allowing companies to create White Space databases with much greater clarity.

On the other hand, we really like Freeview. Knocking out broadcast TV (as opposed to ubiquitous cable/satellite TV) in the United States annoys a few hicks who haven't coughed up for cable, and teenagers watching a second set in the bedroom. Knocking out Freeview in the UK, however, would upset just about everyone.

But Ofcom, like the FCC, is determined that White Space databases are the future of radio licensing, permitting much greater use of the radio spectrum thanks to geographical diversity. Ofcom has already proposed various bands as being next on the list to benefit from the geo-location database approach, so ensuring it works will be critical for more than just the TV bands. ®