Spectrum-Sharing Model Said to Boost Wireless Innovation, But Faces Opposition

In CUS an undetermined number of independent users access spectrum in the same frequency ranges at the same time in a particular geographic area, said Chris Woolford. That definition comes from the EU Radio Spectrum Policy Group, said Woolford, Director of spectrum and international policy for the U.K. Office of Communications (Ofcom) and official reporter for the RSPG’s CUS working group. It resembles license-exempt spectrum but is broader, he said.

CUS stimulates creation of new applications by speeding access to spectrum with minimal barriers, Woolford said. It allows targeting of niche markets perhaps otherwise missed were companies forced through a licensing bureaucracy, he said. CUS lowers regulatory and industry administrative burdens, and fosters efficient use of spectrum, he said. Manufacturers want bands available worldwide to capitalize on economies of scale and interoperability, he said.

CUS has downsides, Woolford said. Signal protection isn’t guaranteed, raising quality of service issues. Once a band is opened to CUS, allocating it for another use is tough, since no one will know the number of users and devices on it. A primary user sharing with CUS users could be constrained from evolving its services, he said. And no one knows how to minimize interference, he said.

A draft RSPG opinion open for public comment says spectrum for CUS will be required across the entire frequency range, with potential advantages to the CUS model in higher and lower bandwidths, Woolford said. Questions remain about how much spectrum to dedicate to CUS, criteria for deciding when CUS is appropriate and how to allocate the spectrum, he said.

Only a few years ago, the RSPG wasn’t even willing to talk about CUS, said SCF Associates Director Simon Forge, offering an economic case for CUS. Spectrum historically has been deemed valuable but “I want to challenge that,” he said. For the idea that spectrum is used heavily substitute the idea that spectrum is owned heavily, Forge said, calling today’s spectrum scarcity an artificial product of “archaic public policies,” he said. The question is whether spectrum is an concrete asset or an intellectual construct destined for rapidly decreasing utility as technology advances, he said.

The commons model may be a better approach, refocusing the debate as it does to device use and away from the ether as a scarce resource, Forge said. He proposed the use of “sublicensed and borrowed” spectrum. The business case for CUS includes mobile services, fixed radio local loop, and new applications for health, elder-care and other social services, he said.

Forge urged European regulators to reshape existing licenses to add subleasing clauses or provisions encouraging sharing. CUS likely will mean a larger regulatory role, since it will require continual national interference monitoring, he said. However, it will diminish the need for regulation on spectrum auctions, lotteries and trading.

Several other panelists questioned CUS’s usefulness. It offers no major solution to spectrum issues, and the key challenge is to find suitable harmonized spectrum for this and other uses, said Anne-Tuulia Leino, Nokia Siemens Networks head of spectrum regulation and ITU-R issues.

Only efficiency should drive spectrum use, said Reinhard Waehlen, a member of the American Chamber of Commerce in the EU’s digital economy committee. Any move to CUS must recognize that some users aren’t ready to share right away and that some always will need dedicated spectrum, he said. Talk of CUS should not mix “political targets, business requests and physics” or everyone will lose, he said.

The white spaces debate in the U.S. is broad, Woolford said. The U.S. leads many EU states in making spectrum available from the digital dividend, he said. Given events in the U.S., the issue of how to work spectrum harder and extract more from it can be expected to gain ground in Europe as digital dividend spectrum is freed, he said. Whether the U.S. model is the best way isn’t yet clear, he said.

The U.S. situation differs dramatically from Europe’s, said Leino. The U.S. is a large country sharing a history, compared with European nations’ diverse histories and 48 borders, she said. In introducing a CUS system, Luxembourg must coordinate with neighbors or face problems, she said. It’s alright for the U.S. to be ahead on this issue, she said. Europe can learn from America’s errors, she added.

Microsoft Seeks White Space Use

Microsoft is a key backer of greater connectivity for consumers, said Andrew Stirling of Larkhill Consultancy, which represents the software giant in spectrum regulatory issues. It has no products in mind, but Microsoft sees high value for consumers in software, services, applications and content accessed online, he said in an interview.

To boost wireless innovation, Microsoft is trying to get regulators to set aside more license-exempt and CUS spectrum on a range of frequencies, Stirling said. CUS is very controversial because licensed incumbents don’t want to see new forms of access and worry about interference, he said, calling the latter fear baseless. So far his company has focused on unused white spaces in broadcast TV frequencies, he said.

Microsoft and other U.S.-based White Space Coalition members want European regulators to allow use of spectrum on a license-exempt basis while protecting existing users from harmful interference, Stirling said. The UHF frequency has special allure for CUS. Coverage is cheaper to provide than in higher frequencies, and lower frequencies sport small neighborhood Wi-Fi applications and mesh networks, he said.

Ofcom has taken the lead in enabling CUS but there’s “substantial resistance” among some incumbents whose interests preoccupy much of the regulatory machinery, said Stirling. Change requires the political will to make balanced decisions and install a regulatory framework, he said. Once that happens, applications soon should be launching, since the white space is there and companies will invest in technologies to exploit it, he said.