AT&T (NYSE: T) is throwing its support behind an emergency petition filed by the National Association of Broadcasters (NAB) calling for better management of the nation's TV white space (TVWS) spectrum.
The NAB last month filed the petition with the FCC seeking to suspend operations of the TVWS database pending completion of a rulemaking or until temporary methods to ensure accurate database information were adopted.
The TVWS database is supposed to monitor where and when unused areas of the broadcast TV spectrum band may be used by an unlicensed device. NAB conducted analyses of the database system over the course of a year and found unlicensed device users provided inaccurate information in all nine of the required fields of the database. More than one-third of the fixed TV white space devices in the database listed erroneous, and occasionally wildly inaccurate, location data, the NAB said.
The FCC has acknowledged problems with the database and says it plans on fixing them before next year's 600 MHz incentive auction.
In a blog post titled "The White Space Black Hole," AT&T notes that after five years of effort, fewer than 1,000 devices are even registered in the database.
"In both the 3.5 GHz proceeding as well as in connection with the incentive auction, the FCC envisions permitting significant unlicensed allocations directly adjacent to a variety of licensed uses. The assumptions underlying this approach are that a database can accurately manage the scope of unlicensed use while providing accurate information on the users so interference concerns can be addressed. NAB's petition now exposes those assumptions to some serious doubts," wrote Joan Marsh, AT&T vice president of federal regulatory, in the blog.
Even in the best circumstances, real-time external monitoring and management of a complex interference environment is a tall order, Marsh said. "But we now learn that database providers have not been able to effectively maintain information on less than 600 TV white space devices. This raises serious questions about the ability of a database to patrol the complexities involved in robust spectrum sharing, including in the 3.5 GHz band."
On the 600 MHz front, the wireless industry has already filed a study raising significant questions about the protection thresholds proposed by the FCC for unlicensed use in the 600 MHz guard bands, she said. On top of those concerns, "we must now add questions about whether unlicensed users will provide reliable location, device and contact information that will be essential to resolving interference concerns should they arise."
AT&T continues to support unlicensed uses in appropriate use case scenarios--it's got more than 30,000 Wi-Fi hotspots and has been a supporter of Wi-Fi offload for some time. But unlicensed services should not be permitted at thresholds that create interference into neighboring licensed allocations, particularly in the 600 MHz band, she added. "And if the industry will be dependent on database policing to manage complex interference environments, the FCC must ensure that unlicensed users comply with database requirements. For these reasons, NAB's petition raises important issues that deserve attention."
Marsh also harkened back to the days when Google (NASDAQ: GOOG) revealed its plans for "Wi-Fi on steroids," calling for a broadband wireless service that would be delivered coast to coast via unlicensed white space devices--all in time for the 2009 Christmas holiday.
But while AT&T and Verizon (NYSE: VZ) were mocked back then for "wasting" billions of dollars on licensed spectrum in the 700 MHz auction, very little movement has happened in the white space arena. Meanwhile, AT&T and Verizon both have gone on to build out LTE, providing services to hundreds of millions of U.S. consumers, she said.
For more:
- see this blog post
Related articles:
FCC promises to clean up error-ridden TV white space databases
FCC supports more unlicensed use of TV, 600 MHz bands
Google, others applaud FCC's plan for 600 MHz unlicensed spectrum