A report from the U.S. Federal Communications Commission clearing the way for the agency to move forward with plans to allow new wireless broadband devices to operate in television spectrum doesn't make sense, two opponents of the plan said.
The report , released late Wednesday, says that five prototype broadband devices tested over the past year were usually able to detect the signals of television stations and avoid interference. But the report also notes that in some cases, the prototype devices were not able to detect the signals of wireless microphones, which also operate without an FCC license in unused television spectrum, often called the television white spaces.
There was a "lot of disconnect" between the results in the report and FCC Chairman Kevin Martin's announcement Wednesday to move forward with allowing new broadband devices to operate in the white spaces, said Mark Brunner, senior director of public and industry relations for microphone maker Shure. The tests showed significant problems with interference with existing users of the TV spectrum, Brunner said.
"In our view, [the devices] did not pass muster," Brunner said.
Martin announced Wednesday that he planned to bring a white-spaces proposal to the entire FCC during its Nov. 4 meeting.
Over the past two years, a group of technology vendors and consumer groups have pushed for the FCC to approve use of the spectrum white spaces, channels in the TV spectrum that aren't used. Microsoft, Google, Dell, Public Knowledge and Free Press are among the supporters of using the white spaces for wireless broadband service.
FCC approval of the devices would spur innovation and create new jobs in the tech sector, and allow consumers to have a new option for broadband service, supporters say. The TV spectrum would allow broadband signals to travel significantly farther than the spectrum used by Wi-Fi, and new lines of smartphone-like devices designed for use in the white spaces would create new demand for tech products, supporters say.
Members of the Wireless Innovation Alliance, a coalition of tech companies and consumer groups, discounted the concerns raised by opponents of the white spaces plan. The FCC has looked at the issue with an unbiased eye, said Ed Thomas, an advisor to the group and former chief engineer of the FCC's Office of Engineering and Technology (OET).
"Everyone is an advocate -- either for or against it," Thomas said of the proposal. "The only neutral party is the FCC." Asked about the cases where prototype devices failed to detect occupied spectrum, Thomas said the report shows that the prototypes can work. The report shows the FCC a way to craft rules that avoid interference, he said. "What has long been supported as good public policy is now supported by good science," added Ben Scott, policy director of Free Press, a media reform advocacy group.
The National Association of Broadcasters (NAB), another opponent of the plan to use the white spaces for broadband service, said the report's "upbeat" executive summary didn't match the tone of the entire report by the OET.
"It would appear that the FCC is misinterpreting the actual data collected by their own engineers," NAB Executive Vice President Dennis Wharton said in a statement. "Any reasonable analysis of the OET report would conclude that unlicensed devices that rely solely on spectrum sensing threaten the viability of clear television reception. Basing public policy on an imprecise Cliffs Notes version of a 149-page report raises troubling questions."
Spectrum sensing was one of the technologies tested on the prototype devices over the past year. Spectrum sensing looks for occupied spectrum in real time, but in field tests, three prototypes incorrectly reported channels as unoccupied when a wireless microphone was operating in the channel.
One prototype, from Motorola, also included a technology called geolocation, which uses technologies such as GPS (Global Positioning System) to match a white-space device's location against a preexisting database of spectrum users.
The Motorola device, while missing occupied spectrum when using only spectrum sensing technology, was about to correctly detect all occupied channels when its geolocation feature was turned on, the FCC report said. If the FCC moves forward with allowing white-space devices, the agency should require geolocation technology to be included on devices, Shure's Brunner said.
After a first round of testing, the FCC concluded in July 2007 that white-space devices did not "consistently sense or detect TV broadcast or wireless microphone signals." But supporters of white-space devices pressed for a new round of testing, which began a year ago.
Seventy U.S. lawmakers, as well as some mobile phone carriers and other groups, have raised questions about interference by white-space devices.
The NAB called on the FCC to seek public comment on the report before moving forward.