Motorola said Aug. 7 its geolocation device operated successfully in the Federal Communications Commission's ongoing white spaces field trials. White spaces are the unused interference buffer spaces between digital television channels that a number of tech companies want to use to deliver unlicensed broadband services.
The spectrum between the channels will become available after Feb. 17 when broadcasters make the switch to digital broadcasting. The FCC began testing white spaces devices with mixed results in January using a prototype device supplied by Microsoft. In July, the agency moved the tests outdoors using devices from Motorola, Philips, Adaptrum and InfoComm International.
"It worked as well as we said it would," said Steve Sharkey, Motorola's senior director of regulatory and spectrum policy. "It went really well."
Motorola's device was the only one using both geolocation and sensing technologies, while devices from Philips, Adaptrum and InfoComm relied only on sensing to detect existing TV channels. Motorola primarily relied on combining geolocation with an FCC database of channels to find spectrum in the white spaces that would not interfere with existing TV channels.
"That was one of the key things for us," Sharkey said. "It [the device] knows what's in the area [and] what channels to use and picks out the best channel. From our point of view, geolocation has to be part of the solution."
The testing was conducted in a variety of conditions including a regional park in the Washington-Baltimore area, BWI Airport, downtown Washington and Ellicott City, Md. Sharkey said tests of the devices using only sensing technology "went well but missed some channels."
Sharkey said using the geolocation mode provided "Absolute, solid [interference] protection ... the device knew what to avoid."
Motorola will not be involved in the next stage of outdoors testing, when the FCC begins testing for interference with wireless microphones. In a May 1 filing with the FCC, the National Football League, Major League Baseball, the National Association for Stock Car Auto Racing, the National Basketball Association, the National Hockey League, the National Collegiate Athletic Association, the PGA Tour and ESPN all opposed the use of white spaces, fearing interference with their wireless mics.
"These devices could knock out wireless communications systems like headsets used by coaches and officials, microphones used by referees to announce penalties and calls, and microphones used by journalists to conduct interviews with athletes and coaches," the coalition contended.
Sharkey, though, said the problem could easily be solved with beacons for the microphones that a white spaces device would detect and avoid.
When the FCC concludes the outdoors testing, the agency will then prepare a report and make overall recommendations on the use of white spaces devices. If the FCC supports the use of white spaces, device makers like Motorola could start manufacturing technology for laptops, smart phones, PDAs and set-top boxes that can utilize the white spaces. All of the devices would have to be certified by the FCC.
"It's really ideal spectrum for rural broadband and we see uses in land-mobile applications," Sharkey said. "We view white spaces as somewhat similar to Wi-Fi. When it was first approved for use, no one knew all the applications, devices and form factors that would evolve."
Opposition to the use of white spaces is led not only by sports leagues but also the NAB (National Association of Broadcasters), which fears interference, and some lawmakers who want the white spaces spectrum to be auctioned off the highest bidder.
"NAB has no quarrel with field tests, but based upon multiple failures of unlicensed devices in laboratory testing thus far, we remain highly skeptical that this technology will ever work as advertised," the NAB said in a July 7 statement.
Verizon added its voice to the debate Aug. 8 when Verizon Executive Vice President Tom Tauke told reporters in Washington, "Generally we have favored licensed spectrum." Tauke added, however, "Presumably, somewhere down the line, there will be technology that develops that potentially could use white spaces without interference. So we have to be open to that potential and look at what is the appropriate policy."