The Channel Wire

March 25, 2008

A proposal by Google to have the U.S. Federal Communications Commission (FCC) open up the so-called white space of unused TV broadcasting spectrum for use by mobile broadband services is being opposed by the National Association of Broadcasters (NAB), which said Tuesday such a move would result in wireless devices interfering with digital TV broadcasts.

In a statement published on the NAB Website, Executive Vice President Dennis Wharton said Google has failed to provide a valid method for protecting digital TV broadcasting from interference from the unlicensed wireless devices that would use the spectrum under Google's proposal.

On March 21, Google asked the FCC to consider opening the white space spectrum that could be used to operate new wireless phones and devices based on its Android platform, which mobile equipment makers plan to use to develop Internet-ready phones.

Rick Whitt, Google's Washington telecom and media counsel, wrote to the FCC that "spectrum-sensing technologies" under use now by the military, could be deployed to automatically check to see whether a channel was open before using it, thereby avoiding interference with other devices. He said the enhancements "will eliminate any remaining legitimate concerns about the merits of using the white space for unlicensed personal/portable devices.

"There are many ways to safely and reliably protect DTVs (Digital TV) and wireless microphones, not all of which require spectrum sensing," Whitt added. "Last fall, Motorola submitted a proposal in this proceeding that relies on a combination of geo-location (to protect broadcast TV) and beacons (to protect wireless microphones). Google believes both concepts, along with a "safe harbor" approach, should be seriously considered for incorporation into the FCC's service requirements for the spectrum." But the NAB's Wharton strenuously disagreed with Google. "We are pleased that Google now seems to realize that spectrum sensing alone won't protect viewers against interference from unlicensed devices," Wharton wrote. " Unfortunately, simply adding geolocation and beacon sensing does not mean that mobile operation is suddenly feasible. Portable, mobile personal device operation in the same band as TV broadcasting continues to be a guaranteed recipe for producing interference and should not be allowed under any circumstances." Google also proposed stablishing a "safe harbor" for wireless microphones in channels 36-38. No TV white space device would be permitted to transmit in these channels. This will also protect medical telemetry devices and radio astronomy services, which are licensed to use channel 37.