White Space Battle Front and Center at AES

By Ken Kerschbaumer

A lively presentation at the AES convention on Saturday by Dave Donovan, president of MSTV and Mark Brunner and Edgar Reihl of Shure focused in on the impending battle over allowing unlicensed personal, portable consumer electronic devices into spectrum currently used by wireless microphones users and DTV transmission. The negative impact, namely mic interference that would end the use of wireless microphones across the country and the inability of over-the-air viewers to receive a DTV signal, have caused many camps to mobilize in Washington DC.

David Donovan, president of Maximum Services Television (MSTV), a trade organization representing more than 500 local TV stations, says the time is now for sports leagues, teams, broadcasters and local TV stations to make their voices heard concerning the future of over-the-air DTV services.

“This is raw politics,” he says. “This is Microsoft and others wanting access to $5 billion of spectrum for free.”

The situation in Washington is very fluid with respect to legislation. Brunner says that HR 1597, Jay Inslee of Washington state’s bill to allow for the devices, currently has 8 co-sponsors. HR 1320, a bill from Bobby Rush that would protect incumbent users, has 13 co-sponsors. “There are also dozens of congressional letters to the FCC reinforcing interference protections,” says Brunner.

Those letters, however, could be for naught if FCC Chairman Kevin Martin gets what many believe he wants: engineering test results that show that prototype devices can properly sense existing signals. If that occurs he could then allow for unlicensed consumer devices to be deployed.

The concern among engineers in the professional audio industry (and TV broadcast engineers) is that the current testing does not meet the typical standard of thorough testing. For example, the FCC office of engineering and technology will not test unlicensed devices in a wide variety of terrain or broadcast reception environments.

More troubling to Donovan is that Microsoft says the devices that failed the first round of testing this summer were “broken.” The claim? Because the auto-sensing part of the device was defective the device was unable to locate existing signals and fired up, causing interference. “So what happens when a consumer has an actual device and it breaks?,” asks Donovan. The though of thousands of “broken” devices firing up and causing interference is just one of many reasons for concern.

Donovan says he expects the FCC to make its ruling in November or December when additional testing is completed. That’s why, adds Donovan, Reihl, and Brunner, now is the time to file comments with the FCC.

“Wireless mics are at the front end of the audio chain and when there’s a problem there is often no way to go back and fix it,” says Reihl, Shure technology director, advanced development. “One interfering device can invalidate an entire frequency coordination plan.”