The Federal Communications Commission last month approved a notice of proposed rulemaking to allow unlicensed devices to operate in the broadcast television spectrum in areas where the spectrum is not being used by television stations. The ruling is expected to benefit providers of high-speed data services, such as wireless Internet service providers (WISPs) and mesh network operators.

The rulemaking was approved unanimously. “Consumers need and want more broadband,” stated FCC Chairman Michael Powell. “We want as many tools in the [broadband] toolbox as possible.”

But at least one commissioner expressed concern for both broadcasters and consumers. “The American people care a lot about the quality of their television reception,” Commissioner Jonathan Adelstein said. “Television broadcasts are viewed by people as perhaps the most sacred use of public spectrum. Their TV is not to be trifled with. We will hear an earful from consumers if this is not done right.”

Adelstein also is worried that the NPRM is being introduced in the middle stages of the digital television transition. He expressed concern about the “wisdom” of allowing unlicensed operations in vacant bands before the DTV transition is complete.

However, Ed Thomas, chief of the FCC's Office of Engineering and Technology, called the NPRM a “win-win-win situation.”

“It's a win for the public, for broadcasters and for wireless ISPs,” he said, predicting that a final order would be issued by the end of the year. Thomas added that such an order would spawn economic opportunities for broadcasters to partner with WISPs to deploy new services, such as a marriage of DTV delivery and broadband content.

Spectrum policy-reform advocates also were optimistic. “The difference between what this will let you do and what the old rules let you do is like the difference between a horse-drawn carriage and a Mercedes Benz,” said Jim Snider, research fellow at New America Foundation.

The rulemaking also should open a more powerful avenue for municipalities deploying mesh networks for public-safety applications. Often described as “prime beachfront real estate,” signals below 700 MHz travel easily through solid objects such as trees and buildings, and require far less power to reach their intended receivers.

Lower-cost equipment is another benefit, as is the ability to deploy broadband networks with fewer relay sites compared with current unlicensed bands at 2.4 and 5 GHz. In addition, WISPs operating in 900 MHz, 2.4 GHz and 5 GHz have been clamoring for more spectrum to provide superior services to their customers.

The rulemaking calls for new unlicensed TV-band devices to operate under FCC Part 15 rules using a portion of spectrum currently allocated for use by TV channels 2 through 51, with various groups of channels blocked out to prevent interference with existing services. For example, channels 2 through 4 have been blocked out to prevent potential interference with the operation of home VCR and DVD players and cable boxes. Also blocked out are channels 14 through 20, which already are allocated for secondary use by land mobile radio services, while channel 37 is blocked to prevent interference with radio astronomy applications.

Finally, UHF spectrum currently used by channels 52 through 69 is not available because it has been allocated for use by a mixture of public-safety and licensed applications.

According to Thomas, WISP unlicensed devices operating under FCC Part 15 could achieve a range of about two miles within a metropolitan area and up to 10 miles on flat terrain. Operators could also choose to trade bandwidth for longer distance coverage. The amount of available spectrum for use would depend upon the market and existing broadcasters. “In New York City, you might only have 50 to 60 MHz available,” Thomas said. “In Montana, you might have 500 MHz.”