Posted by Dan Reed
Corporate Vice President, Technology Policy Group, Microsoft

Around the world, the demand for broadband is booming. This presents great opportunities, but also some challenges. Broadband fuels economic growth and enriches peoples’ lives, but unprecedented traffic levels mean the world’s communications networks are becoming increasingly congested. This is especially true for wireless networks, which use finite spectrum resources. (I discussed the implications of this in a blog post on Microsoft on the Issues last June).

Fortunately, solutions to these challenges are within reach. Governments, academics and companies have come together to develop and demonstrate technologies that use spectrum more efficiently, thereby reducing wireless network congestion. Today marks the successful completion of a 10-month trial in Cambridge, England using “TV white spaces” spectrum. Building on earlier trials in the U.S., Finland, Scotland and Singapore, the Cambridge trial highlights how the world can tap into the vacant TV white spaces to meet the pressing need for more wireless network capacity.

Run by a 17-member consortium (including Microsoft), the trial demonstrated that smart technology can leverage white spaces to extend existing broadband networks in urban areas and bring cost-effective, high-speed connectivity to rural and other areas without broadband access. The full test and measurement report is available here.

In essence, the trial showed that broadband white spaces technology is now ready for prime time. In and around Cambridge, devices equipped with white spaces radios used geo-location databases (supplied by Microsoft Research in Cambridge and Spectrum Bridge) to quickly and reliably identify the frequencies on which they could transmit without interfering with licensed users.

U.K. regulator Ofcom recognizes that this geo-location technology is mature and robust.

“In the past, technological constraints have held back the development of this approach,” said Ed Richards, CEO of Ofcom, in a speech to the Dynamic Spectrum Access Forum in Brussels in March 2012. “That is no longer the case. The constraints are now essentially of regulation and policy.”

TV white spaces spectrum can play a major role in enabling universal access to broadband, and we encourage Ofcom to complete the enabling regulations to make the white spaces spectrum available in the U.K. In the meantime, we plan to team up with other consortium members in the U.K. to help the country harness this valuable natural resource.

International cooperation

The U.S. is set to be the first country in the world to have commercial white spaces broadband services in place. The U.S. Federal Communications Commission has already licensed Spectrum Bridge to provide a geo-location database, paving the way for broader use of the spectrum. The first commercial network began operating in Wilmington, N.C. in January.

We encourage regulators across the globe to study the results of the Cambridge trial and the actions by the FCC, which have validated the benefits of a license-exempt approach to TV-band white spaces. International harmonization on a license-exempt regulatory framework will better enable the manufacturers of devices to achieve economies of scale, just as it has for GSM, conventional Wi-Fi and LTE. Canada, Japan and Korea are among the countries exploring how to harness the TV white spaces spectrum.

Following on the success of the trial in Cambridge and other pilots around the world, and with recent public support from the Infocomm Development Authority of Singapore (more information here and here), Microsoft has teamed with I2R and Starhub to launch TV white spaces pilot projects in Singapore in the coming months. Looking further ahead, the success of the white spaces trials highlights the considerable potential of software-defined radios.

This innovative technology enables a wireless device to use software to dynamically identify and utilize whichever spectrum channel is available, rather than to be restricted to a small number of pre-defined channels. In the future, this smart radio technology will play a key role in both connecting the world and keeping it connected.