• by Erik Sass  @eriksass1, April 18, 2006

A new generation of personal media and communication devices operating in so-called "white space," - a portion of the broadcast spectrum set aside for television station is as yet "unassigned" and thus unused - may interfere with both analog and digital television broadcasts, according to a David Rehr, CEO of the National Association of Broadcasters (NAB), asserted in a letter sent to Sen. Ted Stevens, chairman of Senate Commerce Committee.

The NAB is urging Congress to delay opening up "white space" to unlicensed devices, including those being developed by companies such as Qualcomm, Intel, and Microsoft, until at least early 2009.

By then, the Institute of Electrical and Electronic Engineers (IEEE) is expected to finish hammering out standard 802.22, which should allow the devices to work alongside regular TV broadcasts with little or no interference.

Additionally, Feb. 18, 2009 is the "hard date" agreed by broadcasters for the final switchover to digital TV, at which point broadcasters will relinquish a substantial portion of the TV spectrum for use by broadband devices.

While more bandwidth is scheduled to become available with the transition to digital TV, NAB spokesman Dennis Wharton pointed out that interference with TV broadcasting before the transition is complete could imperil the whole process, setting back both TV broadcasters and manufacturers of the new unlicensed broadband devices.

"We've been in a very delicate transition from analog TV service to digital TV service, and we need to make sure we get this digital TV transition done before we start rearranging the bandwidth," he said. "Our concern is that if there is a problem, people who can't get access to their local television signals are going to be burning somebody, either their local broadcasters, or the unlicensed devices, or the legislature that allowed this to happen, or the FCC."

The manufacturers of the new generation of unlicensed devices have pointed to FCC models, which project no interference with local TV broadcasts. But the NAB's Wharton, says similar FCC forecasts have been wrong in the past. "A lot of the digital re-packing numbers and interference projections are based on computer models, but sometimes affairs don't turn out how the FCC projected it," he noted.