TV white space networks tested

The city of Wilmington, N.C., and the surrounding county of New Hanover, N.C., are among the first communities to test wireless applications using TV white space technology.

The city and county have partnered with TV Band Service and Spectrum Bridge to launch a new experimental network that uses white space spectrum to provide wireless connectivity to surveillance cameras and environmental sensors in a "smart city" deployment.

TV white spaces are the unused TV broadcast channels made available by the recent transition from analog to digital TV. In 2008, the Federal Communications Commission unanimously agreed to open up this unused broadcast TV spectrum for unlicensed use, despite strong protests from TV broadcasters, who argued using this spectrum could interfere with their television broadcasts.

The Wilmington/New Hanover network, which uses an experimental license since FCC rules for white space usage haven't been finalized yet, focuses exclusively on providing monitoring capabilities and data collection instead of providing broadband access to residents.

Initially, the network is being used for three main applications. The first application uses traffic cameras at intersections to provide real-time traffic monitoring for the department of transportation to reduce congestion, fuel consumption, travel time, support local law enforcement, and assist with hurricane and disaster evacuations.

In the second application of the technology, white space spectrum is being used to wirelessly connect cameras in city parks to police for surveillance. Radios are also set up in city parks to provide free Wi-Fi access to residents and city workers.

In the third application, the city and county are using the white space network to remotely monitor and manage wetland areas to comply with EPA regulations. Because these areas are hard to get to, there is no fiber optic network that can be used to transmit data from sensors in the field. So people go out in boats and canoes to collect the data from the monitors. Now using the white space network, the data can be transmitted wirelessly.

Eventually, the network could also be used to provide other applications, such as expanded Internet connectivity for local schools, medical monitoring, and other environmental monitoring, said Rick Rotondo, chief marketing officer of Spectrum Bridge.

But he admits that using white space spectrum is just one way to offer these wireless applications. Existing cellular networks are already being used in some places to deliver some of these services today. Some cities have already tried deploying Wi-Fi for similar applications. And wireless operators, such as Verizon Wireless, promise that 4G wireless technology will provide these same functions.

But Rotondo says that white space spectrum could provide a cheaper alternative to these networks.

"We are not saying that white space spectrum will solve every wireless networking problem," he said. "It's good for certain applications and certain communities. We think it will be one of many types of wireless networks that will be used to deliver these and other types of wireless applications."

Indeed, TV white spaces is expected to be a part of the national broadband plan that the FCC is currently developing and preparing to present to Congress next month. FCC chairman Julius Genachowski has already expressed interest in using white spaces to deliver alternative broadband access. And he has been encouraging companies to think creatively about how to use the spectrum.

When the FCC decided to open the spectrum for unlicensed use a little more than a year ago, it set some preliminary rules for using the spectrum. But it hasn't yet finalized the rules, which means that commercial products can't be sold, and networks using the spectrum can only be used for experimental purposes. Rotondo expects the FCC to finalize its rules in the first half of this year.

It's early days for white space use, and the Wilmington/New Hanover deployment is only the second test bed that Spectrum Bridge has established to test applications for white space networks. In October, the company set up a network in Claudville, Va., a town with a population of about 900 people. Claudville does not have access to DSL or cable broadband services. It's only serviced by dial-up Internet and satellite broadband.

The white space network provides connectivity to the local school, which uses a Wi-Fi router to provide Internet access to students and teachers. The speeds are modest, only about 1 megabit per second, Rotondo said. But with better radios, speeds could be much faster.

Rotondo said that the Spectrum Bridge networks are simply to show what is possible with white space spectrum and technology. The company won't be building white space devices and it won't run a white space network. Instead, it is creating software that can be used by white space products to mitigate interference. Spectrum Bridge has created a data base that keeps track of available white space spectrum, and it's developed software, which can be used by device makers to check for available spectrum to avoid interference.

That said, there are plenty of companies interested in building products around white space spectrum. Motorola, Dell, Google, and Microsoft are among the technology companies that have been lobbying for the use of white space spectrum. And it's likely some, if not all, will develop products and services that use the spectrum.