The switchover to digital delivery of terrestrial TV completed in the UK several years ago, but even before analogue signals were put fully to rest, airwaves regulator Ofcom was thinking about potential uses for these newly liberated slices of spectrum, known as TV white spaces. Ofcom and partners have been conducting tech trials ever since, the most recent of which hooked a few of London Zoo's cutest attractions up with webcams that broadcast over white space frequencies (the streams are still live, by the way). And, with lessons learnt and successes counted, Ofcom has today formally approved TV white space technologies for use. That's not to say Ofcom's done playing its part, though, as it now has the job of managing the airwaves and telling devices how to behave. Regulators gotta regulate, you know?
White space frequencies are extra useful in many respects. They travel far and pass through walls in a way other wireless signals don't; plus, we need all the free spectrum we can get to deal with growing data demands. There's one slight problem, though, in that digital TV signals take up some of the bandwidth, and certain equipment used by broadcasters (think on-site news crews) and at events such as concerts intermittently use white space frequencies as well. Thus, Ofcom still needs to oversee proceedings, so it can minimize the chance of signals interfering with one another. It's initially taking all precautions to avoid any interference catastrophes, but hopes to relax the rules when it has a better understanding of all potentialities.
White space spectrum needs to be shared judiciously, which is why devices must be able to communicate with Ofcom's databases. These will manage requests and feed rules back to the hardware, telling it where it can find dead air, when it can use it, what power level it can operate at, among other guidelines it must abide by. So, although white space spectrum is now technically open for use, Ofcom and friends still need to draw up rules and regulations, get databases in place and complete other preparations before it's truly live. There's plenty to do, but Ofcom expects technology utilising TV white spaces will be up and running before the end of the year. Ofcom also anticipates everything it's learnt and is still learning about spectrum sharing will come in handy when the time comes to tap underused airwaves in other spectrum bands.
[Top image credit: Lee J Haywood/Flickr]