Software giant Microsoft has announced that it is leading a consortium of several UK Internet Service Providers (ISP) and tech firms ( BBC , BT , Sky Broadband (BSkyB) , Nokia , Neul , Spectrum Bridge Inc , TTP , Cambridge Consultants and Samsung ) on trials of a new Mobile Broadband solution in Cambridge, which will make use of the "white space" radio spectrum that exists between TV channels.

Most Digital Terrestrial TV (DTV) channels in the UK operate between the Ultra High Frequency (UHF) bands of 470MHz and 790MHz, which travels further and more easily through walls. Each TV channel is given a slice of this spectrum and a small gap (i.e. the white space) is then left between the channels to, among other things, limit the potential for interference.

White space technology is increasingly being seen as a potential solution to the growing problem of congestion in Wi-Fi networks (2.4GHz) and could also be used to extend Mobile Broadband coverage. Several firms are known to be conducting trials and BT recently confirmed its own project on the Isle of Bute (details here).


Microsoft's trial, much like the others, seeks to show that manipulating such gaps in the spectrum can be done without causing problems for existing DTV services. It sounds easy enough but achieving this is actually far more difficult than might first appear.

According to Ofcom's current consultation on the use of white space solutions, one key difference is that the router/modem (connectivity kit) would first need to consult a list of databases hosted online. The router will then describe its location and device characteristics to one of these databases on a regular basis. The database is then able to return details of the frequencies and power levels that it is allowed to use. TV channels move around all the time and so this is very important.

At this stage it's still far too early to know whether or not white space technology will end up being viable. BT recently claimed that its initial results "have been very promising," before warning that a further live July 2011 customer trial would be needed. Similarly Microsoft's trial is due to start this Wednesday.

Meanwhile Ofcom is working to produce a draft Statutory Instrument, which would make white space devices licence exempt. The whole process should be completed by the end of 2011. By that time we should have a good idea of whether or not white space solutions are truly viable.

UPDATE 10:35am

The official press release has now been sent along, complete with an additional quote and details. We've updated the item accordingly.


The consortium chose Cambridge for the trial because, they claim, it has a long history in developing novel wireless communication technologies and offers an environment for testing diverse uses of the TV white spaces network.

The city is distinguished by a dense mixture of buildings, including the historic stone buildings of its colleges, which offer a unique opportunity to demonstrate the penetration of TV white spaces signals when compared with other higher frequency networks such as Wi-Fi. And although Cambridge itself has good broadband access, some neighbouring villages suffer poor broadband service, allowing the advantageous range of TV white spaces communications to be demonstrated.