Microsoft and Philips complete more white space testing

Microsoft and Philips Electronics are pushing the Federal Communications Commission to retest devices that detect broadcast TV signals.

On Friday, the companies filed results of their most recent test results that showed their devices effectively detected broadcast signals. In an ex parte document filed with the FCC, the companies said they had conducted over 1,000 measurements in New York and California and they determined that the prototype devices were able to detect over-the-air TV signals at very low power levels with 100 percent accuracy.

"What the results of these tests mean is that with we can determine with great certainty whether a TV channel is vacant or occupied," said Ed Thomas, technology policy adviser and partner at Harris Wiltshire & Grannis, the firm representing the White Space Coalition. "And if the channel is occupied, the device won't transmit any signals over that channel."

Technology companies, such as Microsoft and Philips, would like to build devices that can use unlicensed spectrum between the TV channels. This spectrum is known as "white spaces". And companies, which include Microsoft, Intel, Google, EarthLink and Dell, believe having access to this spectrum could unleash a wave of wireless innovation. They've formed a coalition called the White Space Coalition that has been lobbying the FCC and Congress to open up this spectrum.

Not surprisingly, TV broadcasters oppose allowing any unlicensed device to use white-space spectrum because, they argue, these devices would interfere with television broadcasts, potentially harming the federally mandated transition from analog to digital TV service.

Thomas, who presented the findings to FCC engineers on Thursday, said that he hoped the FCC would conduct its own field tests to corroborate the coalition's findings.

The FCC has already tested both prototypes. The Philips device was tested in the laboratory and performed well. But the Microsoft device, which was tested in the field, failed to detect digital TV signals. Microsoft says the results of the FCC test are invalid, because the device the FCC tested was defective. Thomas said that the coalition's most recent field tests prove that the device actually does work.

"We've put a tremendous amount of data on the record with the FCC," Thomas said. "And our hope and prayer is that the FCC conducts the same tests and gets the same results. If they do, we are confident that the FCC will accept our position."

A spokesman for the FCC said that Chairman Kevin Martin said at a recent press conference that the FCC is willing to do additional testing on prototype devices.