FCC testing of devices designed to operate in the spectral “white spaces” between broadcast television channels was completed this week, which could allow the commission to approve rules for the much-anticipated spectrum before the end of this year.

Motorola’s geolocation solution—utilizing GPS location technology with a database of broadcast TV stations’ coverage area to ensure that the device does not interfere with those channels—performed well in all of its tests, said Steve Sharkey, Motorola’s director of spectrum and standards strategy.

“We were very pleased with the tests,” Sharkey said during an interview with Urgent Communications. “The FCC did a good, comprehensive job on testing, beginning with the lab test and moving to an uncontrolled, real-world environment to identify the factors.”

Because it uses geolocation, the Motorola device was not included in the FCC’s most recent tests, which were used to determine the ability of sensing-based white-spaces devices to avoid interference with wireless microphones used during a Washington Redskins’ preseason game and during a Broadway production of Phantom of the Opera. Various media outlets reported that the sensing technologies did not always prevent interference with the wireless microphones at these venues.

“[Sensing only] was not an approach that we supported,” Sharkey said. “We’ve got a different mechanism for protecting wireless microphones, based on a beacon and a geolocation database.”

Geolocation databases can be used to prevent interference from static events that are planned in advance, such as football games and theater productions, he said. For mobile TV crews reporting from unpredictable news locations, the vehicle can be equipped with a beacon that tells white spaces not to operate on the channels being used. For other wireless-microphone uses that are not planned—and as such are not practical for beacon deployment—“safe harbor” spectrum could be established, Sharkey said.

With white-spaces testing completed, the FCC is in position to approve rules for the vast amount of spectrum that currently is unused, but the agency has not announced a timetable for such action.

“They set a goal early on to get rules set in time to have white-spaces devices available for the DTV transition in February 2009,” Sharkey said. “It may be too late in 2008 to make that goal right now, but they have a full record now and are in a position to move forward … before the end of the year.”

Congress is monitoring the situation closely. Eight members of Congress yesterday sent a letter to FCC Chairman Kevin Martin, urging him to establish rules that would enable the white-spaces spectrum to be used to provide broadband coverage to rural areas and support wireless applications for various business uses.

Most industry sources have expected most of the white-spaces spectrum to be designated for unlicensed use, but U.S. Rep. John Dingell (D-Mich.)—chairman of the House Energy and Commerce Committee—last week wrote a letter to the FCC, asking Martin to consider reserving at least a portion of the white-spaces spectrum for licensed uses.