FCC Holds Workshop on Unlicensed TV Band Devices

The FCC held a LEARN (“Learn Everything About Reverse Auctions Now”) Workshop on Unlicensed Spectrum Issues last Friday. While the two-hour Nov. 8 session provided a nice forum for dialog about the use of wireless devices in the ever-shrinking amount of white space TV spectrum, it didn’t provide much in the way of answers to this growing problem.

Given the different interests competing for what is certain to be become a much smaller amount TV band spectrum after incentive auction television station repacking, I didn't expect the workshop to result in any grand solutions and there weren't any. Much of the workshop was devoted to different groups explaining how they were using TV band spectrum for wireless microphones and fixed link TV white space systems. Participants talked about new technology for personal portable and in-home TV white space systems in the future, but said commercial development depends on some assurances that spectrum to operate them in will be available.

Although FCC Chairman Tom Wheeler made some comments at the start of the workshop, much of the time was spent in explaining different TV band unlicensed applications, as well as special issues surrounding use of TV Channel 37 (not now authorized for broadcasting).

The most interesting discussions about how spectrum could be shared (or not) began about two hours into the workshop.

Bob Seidel from CBS made a case for reserving some spectrum for broadcasters for wireless microphones. He stated that breaking news coverage makes sharing wireless microphone spectrum difficult, if not impossible and also described problems he had in registering microphone use at certain locations, even when he knew in advance news events were happening there.

Another participant talked about the extensive use of wireless microphones at NBC’s 30 Rockefeller Center operations on TV spectrum shared with stations less than 75 miles away that are not available to TV white space devices. He supported his argument for fewer reserved channels for wireless microphones with registration data from the Spectrum Bridge database.

Other participants explained how bandpass filter characteristics and out-of-band emission limits can affect spectrum use, with one individual cautioning the FCC to be careful allocating spectrum. He stated that due to the need for guard bands and protection to services on adjacent channels, the wrong decision could end up providing 3 MHz of usable spectrum to one service, but making 8 MHz unavailable for other uses.

The video recording of the workshop is now available on the FCC Learn Workshop to Discuss Unlicensed Spectrum Issues event page.

Also, see my article FCC Reschedules Unlicensed Spectrum User Workshop for a list of participants.

Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.