Google, CTIA Dig in on White Space

Fresh off the 700 MHz auction, Google and CTIA-The Wireless Association laid down fresh versions of their proposals for use of devices in the unused portions of the DTV spectrum known as white spaces.

Google, which launched the topic into major media outlets with a press teleconference, has a vision for mobile unlicensed devices. In an FCC filing, Google says the white spaces “offer a once-in-a-lifetime opportunity to provide ubiquitous wireless broadband for all Americans.”

The company also said its Android open source platform for mobile consumer devices can provide that broadband in the white spaces, if the FCC crafts the right rules enabling both fixed and mobile unlicensed devices.

Google proposed interference protections similar to those proposed by Motorola. These include geolocation technology, in which a device compares its location against a database of known TV channels in use, with the added enhancement of requiring a signal from the geolocated devices indicating a channel was safe for transmission. It also proposed a beacon system to protect wireless users, in which devices in use could transmit a coded beacon to prohibit use of channels that would cause interference.

Google also touted the promise of spectrum sensing technology, by which the devices would detect DTV channels in use and then avoid transmitting on those frequencies.

David Donovan, president of the Association for Maximum Service Television, said the Google proposal offered nothing new.

“Google’s supposed ‘new plan’ is understandable given the repeated failure of spectrum sensing technologies during the most recent round of FCC lab testing,” he said in a statement. “We are happy Google recognizes that relying on sensing will not protect consumers from interference to their new DTV sets and government subsidized converter boxes. Hopefully, this will put an end to the current ‘sensing’ approach advocated by Microsoft and others. ... Given Google’s approach not to pay a market price for spectrum in the 700 MHz band, it is not surprising that it is turning its attention to the TV band.”

CTIA-The Wireless Association, whose members already own wireless networks, renewed its proposal for rules that would allow a combination of area-wide licensed users, with spectrum to be licensed by auction, while setting aside some spectrum for the study of future unlicensed use.

“This licensed approach will foster intensive use of this spectrum, while ensuring that broadcasters and other incumbent TV band users have recourse against identifiable entities in the event interference occurs,” the group wrote in an FCC filing.

Read more about the white space testing in the April 9 edition of TV Technology.