2009 was, for the most part, quiet when it came to white-space related news. But actions happening this week may set the stage for actual FCC type-accepted white-space devices by the end of 2010, especially now as the FCC searches for more spectrum for broadband deployments.
On Monday, nine entities applied to become white-space database coordinators. Because white-space spectrum lies in those unused pieces of TV spectrum, white-space devices must operate to prevent interference with surrounding signals such as TV broadcasts and wireless microphones.
The FCC's technical conditions require that both fixed and portable devices include geolocation and spectrum-sensing applications capable of integrating with an FCC database that comprises TV signals and the location of venues such as stadiums and concert arenas that use wireless microphones. Geolocation technology will be used to map the location of the device and compares it to the location of TV stations in an area.
The more well-known names applying to become database coordinators include Google, Spectrum Bridge, Telcordia and Comsearch. Getting the database coordination right will be the most important task as these new networks will be driven by this pooled database approach.
"This changes the whole idea about how people build networks and spectrum," Spectrum Bridge Chief Technology Officer Peter Stanforth said in an interview. "Traditionally, when you build a network, you have to find spectrum and build it to that spectrum. In the white-space environment, we're talking about a radio that is frequency agile and based on a database. The pool of spectrum is based on location. If more spectrum is made available or taken away, it doesn't matter. The only thing that changes is the information in the database."
Of course, that's why the FCC likes white-space spectrum as it gives the commission the ability to be flexible about what spectrum is available. Interestingly, we are likely to see Spectrum Bridge, which recently built an experimental white-space network in small rural town Claudville, Va., become both a database coordinator/network architect given the fact that many former Motorolans from the mesh network side, including Stanforth, are working at Spectrum Bridge.
The FCC is still hammering out the the final rules for white-space use, and some questions are still unanswered when it comes to the database. The database must be able to check for other registered devices, making sure the device is registered with the database and calculating accurate maps to identify TV channels and other services operating in the spectrum.
While finding TV stations and other FCC-certified devices is relatively straightforward, there are other devices that don't have the FCC stamp on them that also need to be protected. Stanforth said these devices include cable head ends that cable providers use to receive television signals. Cable operators would need to register these devices with the database. But the big question mark surrounds wireless microphones that are used in a variety of venues, including stadiums, theaters and government facilities. Many microphones operate illegally in the 700 MHz band, and the FCC has yet to clarify how these devices will be classified, Stanforth said.
Wireless microphone provider Shure is backing legislation proposed by Rep. Bobby Rush (D-Ill.) that seeks to protect 13 different classes of wireless microphone users from interference. The bill would require the FCC to provide access to an electronic database where wireless microphone users would register their frequencies to protect their operations.
Stanforth believes the FCC will name white-space database coordinators and issue final rules governing the band in the first quarter. Once that happens "we would anticipate a huge flurry of activity ... Players don't want to commit until they know what the rules are," he said.--Lynnette