Diving into the digital divide

New Hanover County, City of Wilmington launch nation's first wireless network using television frequency 'white spaces'

By Todd McGee
Communications Director

When television broadcasters made the switch from analog to digital TV in June 2009, they left behind a lot of empty space – white space, to be technical.

New Hanover County Board of Commissioners Chairman Jason Thompson discusses the impact that the experimental wireless network will have on providing new government services. (Photos by Todd McGee)

In the telecommunications industry, white spaces are frequencies that are allocated for broadcasting purposes but are not used locally (think back to the days before cable when most TVs had 50 or so channels but could pick up signals from only a handful of stations in the area).

Full-power analog TV broadcasts operated between the 54 MHz and 806 MHz TV frequencies (channels 2-69) in the United States. Since the switch to digital, full-power TV stations can now operate only between 54-698 MHz, which frees up a significant amount of broadcast frequencies – or white space. In addition, the digital signals use up less space on the spectrum, which means more of them can be packed into fewer channels, freeing up even more space.

What to do about the white space has been an ongoing issue for the Federal Communications Commission since Congress announced its intention in 2005 to convert to digital broadcasts. The FCC voted unanimously in November 2008 to approve the unlicensed use of white space over the objections of TV broadcasters, who fear their signals will be interfered with as people begin using the white spaces.

While bureaucrats and lobbyists argue about rules and regulations, innovators are already looking at ways to utilize this opportunity.

New Hanover County and the City of Wilmington were selected by the FCC to serve as the pilot market for the nation's first "Smart City" White Spaces Network Trial, and the two governments, in a partnership with TV Band Service LLC and Spectrum Bridge Inc., have taken the first steps toward tapping into this potential.

"Building upon our current information technology investments, TV white spaces will help the county make the most efficient use of our existing resources and infrastructure," said Jason Thompson, chairman of the New Hanover County Board of Commissioners, during a Feb. 24 event commemorating the launch of the trial. "It is allowing us to extend video and data connectivity to areas that were once outside the bounds of current technology due to cost or environmental concerns."

Philip Hill, a communications engineer with Spectrum Bridge Inc., demonstrates the television equipment being used to wirelessly transmit data being collected from a monitoring device set up at a pond.

The city and county have installed video cameras in high traffic areas to provide real-time traffic monitoring. The county has upgraded its public parks by placing video cameras to help with public safety issues and extending high-speed wireless access to enable citizens to stay connected.

Officials have placed sensor devices in various wetlands areas to collect data required by the Environmental Protection Agency. The sensors continually broadcast their data back to the monitoring station, enabling personnel to retrieve the data on a real-time basis instead of having to make more costly spot checks by physically driving or boating to the sensor. This not only cuts down on the time and effort needed to retrieve the data, but also allows problems to be identified and resolved more quickly, thereby providing a better service to citizens.

Dr. John Chapin, a consultant for TV Band Service LLC, said the trial will help identify the many ways in which organizations, including government agencies, can benefit from this emerging field.

"We expect to learn a lot about the technology and the uses of the TV white spaces through this trial," Chapin said. "We're pulling together a variety of radios and applications. We're excited to grow the trial network and invite future participation by radio vendors, government organizations and potential users."

More than 100 reporters, entrepreneurs, government officials and researchers from N.C. State University's electrical engineering department attended the Feb. 24 demonstration event at the Screen Gems Studios in Wilmington. Officials showed live footage from cameras installed at an area park and a nearby highway and demonstrated data that was being collected from a monitoring device set up at a pond on the facility.

Because these applications use the airwaves to transmit their data, there is no need to dig and bury expensive cables, and there is no need to visit the location to retrieve the data. In addition, the units can be powered by a solar cell, making them portable and environmentally friendly – not to mention exceedingly cost-effective, Chapin said.

For instance, if a city is doing a big road construction project, the city may want to establish a traffic camera at the site because citizens may be interested in monitoring the traffic – as well as the progress of the project. Because it is using wireless technology, no cables would have to be run to the camera, meaning the units can be set up quickly. Once the project is finished, the camera could be taken down and moved to another location, Chapin said.

The advantage of using the white spaces is that the signals can travel much further than a traditional wireless network and can penetrate buildings and other impediments. Signals can travel as far as two miles regardless of the terrain, and can reach even further if the area is flat and open, Chapin said. In addition, the signals can carry more data, resulting in faster speeds for Internet access. And because the signals don't travel as far as traditional analog broadcast signals, a station can be used on different sides of the county at the same time to deliver different signals, Chapin said.