Cambridge Trial Will Explore Better Use of Broadcast Spectrum

Imagine a five-lane freeway at rush hour. Except on this freeway, four of the lanes are assigned to specific purposes and can only be used by a certain class of vehicles. Some of the assigned lanes contain a steady flow of traffic, but others remain clear most of the time. Meanwhile, the rest of us, traveling in thousands of cars, must use the single remaining lane for our commute.

Thankfully, this situation is not likely to happen on our roadways, but it does with radio spectrum. Our laptops, tablets, smartphones and other connected devices use spectrum to connect and transmit data. When the metaphorical spectrum traffic lanes get jammed, there is no way to avoid the congestion and switch to a clear lane. As a result, users feel the pain of frequent dropped calls and degraded quality of service.

With more than five billion cell phones and a growing “Internet of Things,” the demands we’re placing on spectrum have run headlong into the traditional ways that society regulates and allocates spectrum use, based on approaches that are nearly a century old. This is an issue that goes well beyond dropped cell phone calls, and can’t be solved solely by adding fiber optic networks and cell sites.

Fortunately, a new generation of radio technologies may hold the key to unlocking large, often unused chunks of spectrum – first in the TV broadcast bands (so-called “TV white spaces”) — with the help of online databases and devices that enable wireless traffic to flow in the most efficient manner and avoid interfering with licensed broadcasts and other primary uses.

Today, a new trial is being launched in Cambridge, England to help tackle this growing global issue. The Cambridge TV White Spaces trial is notable not only as an exploration of how cognitive radio technologies can enable more efficient use of spectrum, but also for the caliber and breadth of the consortium of technology and broadcast organizations involved — BBC, BSkyB, BT, Cambridge Consultants, Microsoft, Neul, Nokia, Samsung, Spectrum Bridge Inc. and TTP. Adaptrum and KTS are also providing considerable hardware support.

Importantly, United Kingdom broadcast regulator Ofcom has granted a multi-site test license that will allow the project to commence. Ofcom’s leadership is key to helping regulators worldwide understand how TV white spaces can address the spectrum crunch.

Consumers today have come to expect and demand anytime, anywhere connectivity. Wireless networks using the TV white spaces can provide connectivity similar to Wi-Fi, but with coverage areas measured in kilometers instead of meters. Radio is also egalitarian in that the cost to link a user 30 meters away is the same as the cost of serving a user several kilometers away. Once a base station is turned on, everyone within range has access. In addition, the more rural the user, the less intensively radio spectrum is utilized, which enables greater data rates for rural users who do not have direct access to fiber or other wired broadband connections.

All of this represents an important technology opportunity, and will create new economic opportunities, the same way Wi-Fi brought a valuable new class of services over the last decade.

As Dr. John Chapin says in the short video below, “The real innovation is the new businesses and new services that are going to be enabled by the low cost spectrum access.”

I’ve said this previously, and continue to believe it true: To realize this vision of cognitive radio and dynamic broadband, we need to fundamentally rethink how we allocate spectrum. A number of the companies participating in the Cambridge trial have worked on these technologies for years. For our part, we’ve worked hard to address spectrum sharing, and design a system that allows cognitive radios to connect seamlessly without interference.

In the U.S., the FCC’s decision to allow unlicensed use of TV white spaces last fall was an important first step toward allowing these new technologies to proliferate. And with the Cambridge trial, the consortium hopes to explore the benefits of even more flexible regulation in the U.K.

I encourage everyone to follow the work being done in Cambridge. The results of the trial could have profound and positive effects on the technology world and society for years to come.

About the Author

Corporate Vice President, Technology Policy Group, Microsoft