Spectrum Bridge Trials Show Promise of 'White Spaces'

While the Federal Communications Commission only Thursday approved the widespread deployment of white spaces for broadband, four existing applications show the versatility of the 'Super Wi-Fi" technology.

Although still considered to be experimental, the applications already provide important functionality and they all have a common denominator: the driving force behind each was Spectrum Bridge, a Florida company that has specialized in spectrum trading and usage.

FCC chairman Julius Genachowski cited the four applications when the vote approving the use of the white spaces spectrum was taken.

"In Claudville, Va., they are providing broadband access to a remotely located elementary school," he said. "In Wilmington, N.C., they are trialing 'smart city' applications to manage traffic and monitor water quality at nearby wetlands. In Logan, Ohio, they are using the white space to deliver telemedicine to healthcare providers. Plumas County, Calif., is utilizing 'smart grid' technologies for electricity networks."

Jeff Schmidt, director of engineering at Spectrum Bridge, said the potential of white space frequencies is "enormous" and now that many of the technical hurdles -- like complex sensing requirements -- have been dropped by the FCC, companies and other organizations can focus on building white space products and services.

"The white space frequencies have very favorable propagation (features)," he said in an interview. "You need to build an eco system. You need to leverage existing technologies like WiMax and Wi-Fi."

Many look at white spaces as simply an extension of Wi-Fi, and while that may be true, the four existing installations demonstrate that the technology will likely lead to broad new uses.

Spectrum Bridge's first application -- in Claudville -- brought wireless broadband to the small community (population about 900) and showed that the technology can be rolled out effectively in an isolated rural community. After setting up a white spaces link in the town center, Spectrum Bridge then sprayed the signals to Wi-Fi routers at locations elsewhere in town.

Spectrum Bridge built its own experimental white space database -- a requirement still being worked on by the FCC -- for all of its applications. The company has submitted a bid to the FCC to provide white space database expertise, which is needed so users can sort through spectrum and avoid interference. The FCC is expected to resolve the database disposition in a few weeks.

The TDF Foundation, which invests in telecommunications projects, and Microsoft supplied some support in Claudville. The FCC gave Spectrum Bridge experimental licenses to build the white space installations. In N.C., Spectrum Bridge found that the propagation power of white space frequencies enabled a system to be built with fewer towers. The application monitors wetlands around Wilmington at a much lower cost than using fiber. "We've identified different ways to show how white spaces can be used in smart city applications," said Schmidt.

In the Hocking Valley, Ohio, Community Hospital installations, Spectrum Bridge utilized Airspan Networks' WiMax technology and Google software to deliver advanced telemedicine to users. The installation demonstrated the easy use of data transfer between first responder vehicles and the hospital, while, in the hospital the technology was able to easily penetrate walls that couldn't be breached using older wireless technologies. The application was also utilized for video surveillance purposes.

Spectrum Bridge's partnership with the Plumas-Sierra Rural Electric Cooperative in Calif. represented the creation of a small smart grid. The trial also demonstrated that broadband can be provided inexpensively to rural inhabitants in scattered locations.

One interesting takeaway from the Spectrum Bridge trials is evidence that WiMax can be useful when linked with white spaces. Schmidt said WiMax gear can be rebranded to work with the newer technology and products should be ready for marketing as early as the first half of 2011.

The missing white space link is the database that monitors spectrum to guide users toward free bands. "It's like an air traffic control system," said Schmidt. "You need a database to keep broadband users from interfering with each other. When a (user) device is turned on, you need a channel map."

Once the final green light is given by the FCC, Schmidt expects to see a rush by vendors to create white space products and services. He predicts fixed high-power wireless installations will begin appearing early next year. "I look for consumer devices with radios embedded in laptops and PDAs to appear in 2012," he added.

At the FCC meeting Thursday, chairman Genachowski noted one analyst was predicting that white spaces apps could generate more than $7 billion in annual economic value.

For Further Reading

FCC Approves 'White Spaces'

FCC Hopes White Spaces Vote Appeases Critics

FCC Chairman Backs Use Of White Spaces