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(Feb. 23, 2009) LAKE MARY,FLA.: An online spectrum exchange has launched a Web site for locating white spaces. Spectrum Bridge created, a data base that combines mapping functions with information on occupied and open TV channels.

These open TV channels have come to be known as “white spaces,” where the computer industry has successfully lobbied to launch unlicensed devices this summer.

White spaces were considered “taboo channels” in analog broadcasting because stacking TV channels one atop another caused too much interference between them. A certain buffer zone remains between digital assignments for the same reason, because TV signals tend to leak. Charlie Rhodes, TV Technology contributor and former lead engineer of the Advanced TV Testing Labs, has demonstrated characteristics of digital signal splatter in his own testing facility.

Besides being occupied by TV signal splatter, white spaces also are heavily used for wireless mics and other professional devices, typically used for live events. Churches, stadiums and theaters are rife with wireless mics, and their use is coordinated with incumbent operators--primarily, TV stations.

Broadcasters and wireless mic concerns alike have strenuously objected to the use of unlicensed devices in white spaces because of their potential to cause interference. FCC interference tests continue to be questioned by opponents, who lost out to computer and software industry giants like Microsoft and Google.

The FCC under former Chairman Kevin Martin approved the use of unlicensed devices in white spaces, once the digital TV transition is complete. The current end date is June 12. The decision to release spectrum without licensing it was a first for the FCC, which typically auctions spectrum or imposes specific public interest obligations on users, as with broadcasting.

The absence of licensing makes devices used within the scheme nearly impossible to trace. It also allows device makers free use of the type spectrum for which AT&T and Verizon recently paid upwards of $19 billion.

The argument to forego licensing is that it will allow more companies to bring a greater variety of products to market more quickly. The Spectrum Bridge Web site announcement provides a synopsis from Ed Thomas, tech policy advisor at Harris Wiltshire & Grannis, the D.C. law firm representing the White Spaces Coalition of Microsoft, Google, Dell, HP, Intel, Philips, Samsung, Earthlink and others.

“White space opens up much needed wireless bandwidth that could provide significantly more access to broadband connectivity, particularly for rural communities,” Thomas said. “There are numerous applications for these soon-to-be-available airwaves. The most exciting ones are those that have yet to be developed and will be stimulated by the technical innovation spurred by this new spectrum.”

A lawsuit challenging the FCC’s white space rules is in the nonetheless works, according to sources familiar with the situation.

The Spectrum Bridge Web site works either via address or geographic coordinate search. A scan of the Los Angeles market yields but one open channel out of 50--Channel 10. A local TV engineer notes that Channel 10 is nestled between two full-power TV signals and therefore useless for even higher power devices.

“No white space for L.A.,” he writes.

Spectrum Bridge was founded two years ago by former Motorola, Lucent and Nortel executives. -- Deborah D. McAdams