White Spaces Devices Work as Advertised, Despite Test, Microsoft Says
Microsoft blamed a broken scanner for sub-par performance of a device designed to operate in the broadcast white spaces without interfering with TV broadcasts. The FCC shouldn’t jump to conclusions since the gear normally prevents interference, Microsoft said. The device failed crucial tests by the Office of Engineering and Technology, according to a report released July 31 (CD Aug 2 p6)). The FCC is expected to give the tests significant weight in deciding whether to allow unlicensed, mobile devices to operate in the band. The idea has the strong support of high tech companies and the vehement opposition of broadcasters.
Sign up for a free preview to unlock the rest of this article
Communications Daily is required reading for senior executives at top telecom corporations, law firms, lobbying organizations, associations and government agencies (including the FCC). Join them today!
“During meetings with FCC engineers last week, Microsoft determined that the prototype device tested by the Commission was working improperly and an internal component was broken,” Microsoft said Monday in an FCC filing. “This accounted for the FCC’s aberrant test results.” Microsoft told the FCC it didn’t understand why OET engineers didn’t test a second device it submitted to back up the broken device, and never alerted the company that the first device hadn’t worked properly.
Microsoft said the device had passed tests in its lab before being sent to OET. “The Microsoft testing revealed that its electronically equivalent device detected DTV signals at a threshold of -- 114 dBm in laboratory bench testing with 100% accuracy, performing exactly as expected,” the company said.
OET has called a meeting on Thursday at its lab in Columbia, Md., to explain the results of its testing. The office released a report on tests of two prototype devices, Microsoft’s and one from Phillips. The second device did perform as expected and was able to detect interference to DTV signals reliably.
David Donovan, president of the Association for Maximum Service TV, called Microsoft’s filing a high-tech version of the “dog ate my homework” defense. “The entire over-the-air digital broadcast system and derailment of the DTV transition is all based on whether a specific device works in a lab,” he said. “The device utterly fails and Microsoft now says, IOops, it was broken’… Imagine the disaster if millions of these devices enter the market and they start to break. These devices should not be let loose in the TV band.”
Donovan said that regardless of Microsoft’s tests the sensing technology proposed is too risky to be considered by the FCC. “Using ’sensing’ to avoid interference in the TV band is unbelievably risky and has never been proven to work the real world,” he said. “If it fails, the interference can go for miles. Moreover, Microsoft’s proposed sensing level (-114 dBm) will not protect digital TV sets from interference. It’s time to stop experimenting with the 100 million digital TV sets that will purchased by 2009.”
The NAB said in response to Microsoft: “The FCC performed rigorous tests on the Microsoft devices, and we are confident that its finding that these devices cause interference to television reception is accurate. Nearly a decade ago, broadcasters and government launched the historic public-private partnership that is bringing the next generation of television to American consumers. Now that the DTV transition is near completion, up steps Microsoft and its allies to jeopardize all that has been accomplished.”
Shure, which has raised concerns about interference to wireless microphones, said how the device tested at the FCC lab isn’t its main concern. “The professional audio industry is primarily interested in the demanding radio frequency environments that exist in dozens of urban markets every day across the country, and we believe performance of these devices will be unacceptable on the Strip in Las Vegas, on the set in Hollywood, inside Soldier Field at kickoff, in the second row of a Martina McBride concert, behind the podium at a political convention, or on Broadway at show time,” Shure said.