Luke Pensworth
The FCC is expected to rule on white spaces September 23, using unused broadcast television frequencies to transmit unlicensed broadband wireless. Former FCC Chairman Kevin Martin first approved the use of White Spaces two years ago and the FCC this September will vote on a final order. The F.C.C. is virtually certain to approve the new rules at its Sept. 23 meeting, says the NY Times.
Because the spectrum will be unlicensed, it could be used for a variety of uses, including providing broadband access in rural areas and in-home wireless networking. Other ideas being explored are using it for wireless connectivity to appliances or to electric smart meters. Broadcasters and the NAB have strenuously objected.
Google, Microsoft and Dell have long lobbied to use white spaces, reports the Washington Post. Google envisions rural networks and remote meter reading. Microsoft has experimented with its own white-spaces network on its campus in Redmond. Dell believes white spaces will spawn innovations for the home.
The largest group lobbying for making TV White Spaces unlicensed was the Wireless Innovation Alliance (WIA). The WIA was comprised of major technology companies such as Google, Microsoft, Dell and Motorola.
White spaces avoid television interference by listening first for any broadcast signal. Then it searches a geolocation database to determine whether any transmitter is near. It won’t transmit until an unused 6 Mhz television channel is found.
Neeraj Srivastava, a vice president for marketing at Spectrum Bridge has been using white spaces under experimental license for nearly two years. He says objections from broadcasters and cordless microphone makers have been solved.
To guarantee that the TV White Spaces network does not cause interference with licensed television broadcasts and other protected TV band users, the system operates under the control of Spectrum Bridge’s intelligent TV White Spaces database. This database dynamically assigns non-interfering frequencies to white spaces devices, and adapts in real-time to new TV broadcasts, as well as other protected TV band users operating in the area.
“The database tells it the channels it can use,” says Neeraj Srivastava. “We’ve built this database covering the entire U.S.. Any latitude and longitude, we can tell the device what frequencies to use.”
Broadcasters, who get their spectrum at no charge courtesy of U.S. taxpayers, have been successfully transmitting different 100,000 watt stations adjacent to each other for the last 5 years, without problems. Nonetheless, the NAB launched a campaign saying a white space transmitter – using one tenth of a watt – would somehow bring terrestrial broadcasting to its knees.
Spectrum Bridge has been testing White Spaces for over a year and they say they’ve been addressing any technical objections:
- In Wilmington, NC, Spectrum Bridge worked with the city to deliver traffic monitoring, security cameras, public WiFi hotspots, and water monitoring for rivers and estuaries.
- For Plumas County, California, Spectrum Bridge built a smart grid, giving the local co-op access to sub-stations and consumers control of their electric meters.
- In Claudville, Virginia, Spectrum Bridge brought broadband to a town that never had it before.
- For Hocking Valley Community Hospital in Logan, Ohio, Spectrum Bridge delivered WiFi to patients and their families.
Converted AirSpan WiMax radios have been used, with no attempt to encode for maximum throughput, says ZDNet.
TV white spaces availability can be found for any location in the US by using the free search tool at Spectrum Bridge’s ShowMyWhiteSpace.com website, or by downloading the company’s free iPhone application.
Once the FCC gives the go-ahead, a new IEEE committee dubbed 802.11AF, has been formed to develop the standard.
