Microsoft, Philips Submit More White-Spaces Data as FCC Vote Nears
Microsoft and Philips gave the FCC extensive new test data, making the case that portable devices can operate safely in the TV white spaces without causing harmful interference. The data are based on about 1,000 measurements taken many places in New York and California.
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The companies hope the Office of Engineering and Technology will verify the data and the FCC will act within months to open valuable new spectrum to use by unlicensed devices to access the Internet. In July, OET said a prototype device built by Microsoft essentially failed testing. Then Microsoft said the device tested was broken. How the FCC will view the various test results remains uncertain, sources said Friday.
“The Microsoft/Philips testing further confirmed that it is technically feasible for white space devices to detect television signals over varied terrains and within buildings of various types at the -114 dBm threshold proposed by the White Spaces Coalition1 - a signal that is far too weak for a television set to produce a broadcast television picture,” the companies said in a filing at the FCC. The companies submitted the data in a 73-page filing with charts and tables.
“I think that we have a very strong case,” said Ed Thomas, a former OET chief representing the two companies. “The case would be much stronger if OET went out and made measurements and confirmed what we did. That’s what we're encouraging.”
OET doesn’t need to rely on tests by his side or the NAB and the Association for Maximum Service Television on the other side, Thomas said. “Obviously we have a bias and MSTV has a bias,” he said. “The only one that isn’t biased is the FCC. Our hope is that they're going to go out and take some of their own measurements and corroborate what we did.”
The NAB took a swipe at Microsoft. “It’s ironic that a company with a track record of developing less-than- perfect products is now claiming to have invented a device that functions with ‘100 percent accuracy,'” the NAB said. “While frustrated users of Microsoft products have come to expect routine system errors and computer glitches, they do not expect the same to hold true for broadcast television service.”
David Donovan, president of MSTV, said Microsoft and Philips’ tests don’t deal with the central issue that the strength of broadcast signals received by next-door neighbors can vary significantly. “The filing misses the point entirely,” Donovan said. “The issue has never been whether signal levels exist at the -114 level or stronger. The issue is whether there are ‘holes’ or ‘hidden nodes’ in a television station’s service area with signal levels below -114. The study provides specific examples of such areas, and proves our point.” For example, he noted, in some of the locations studied the signal strength of a broadcast signal varied widely among the living room, kitchen and basement in a house.
“If you're in a spectrum hole and you don’t get a signal the device turns on and covers an area much larger than that hole,” Donovan said. “You hit a dead spot, the device thinks there is no channel and turns on… The question isn’t whether or not someone living in a hole gets reception. The question is whether anyone living around that hole does.”