WSD prototype failure shows devices not ready for primetime, NAB says

The National Association of Broadcasters (NAB) said Feb. 11 that last week’s failure of a prototype white space device (WSD) from Microsoft being tested by the FCC as part of its second round of testing demonstrates such devices “are not ready for primetime.”

In a written statement, NAB executive VP Dennis Wharton said a comment from Ian Ferrell, director of wireless incubation for Microsoft, to TRDaily saying that the prototype being tested experienced an unexpected power failure was an “admission” by those pushing WSDs that “vindicates beyond doubt the interference concerns expressed by broadcasters, sports leagues, wireless microphone companies and theater operators.”

The prospect of unlicensed WSDs sharing the broadcast spectrum has raised significant concern among broadcasters, who fear the devices, if authorized, would cause widespread interference to DTV transmission and wireless mic users, such as ENG news crews. Wireless mics share TV spectrum in some of the white spaces WSD proponents seek to use.

The FCC’s Office of Engineering and Technology (OET) recently kicked off a second round of testing — both in the lab and the field — of prototype WSDs. A major goal of the tests is to determine whether frequency sensing technology will perform as promised. WSD proponents contend frequency sensing technology can identify used TV spectrum, thus allowing such devices to operate on a frequency where there is no chance of causing interference. The results of the tests will be entered into the record and help the commission decide if the use of such devices should be authorized, and, if so, what performance parameters must be met. In July 2007, the OET concluded its first round of WSD tests, finding that the prototypes submitted generally failed to sense the presence of TV signals.

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