email@example.com As regular readers of Pro Sound News surely have noted, the digital migration of television broadcast has created a scenario in which large swaths of the radio frequency spectrum long reserved for television have been repurposed by the Federal Communications Commission for non-broadcast use. The 700 MHz band is now in private hands, auctioned off for a one-time infusion of cash into the federal coffers. Radio frequency spectrum is a limited resource, with sections of bandwidth better suited for specific applications as bound by the laws of physics. Our mobile society has developed a voracious appetite for bandwidth, and the television spectrum is a particularly tasty piece of the RF pie.
Broadcasters have not suffered much throughout the process in terms of their ability to transmit programming. While some have had to adjust to new frequency assignments, that migration was largely concurrent with the overall digital migration. New proposed spectrum reallocations include compensation for affected broadcasters who shift away from additional bandwidth that will become part of the next round of spectrum auctioning.
Where our industry is most affected is in the used of wireless microphones, comms and monitoring gear. Legacy television broadcasting relied on regional frequency assignments that left unused bandwidth in place to protect broadcasters from interference from overlapping signals. Professional audio has long taken advantage of these open spaces to slip in low-powered operation of wireless audio devices. As digital technology allows greater density of operation, the reallocations have shifted television broadcast into condensed blocks of frequencies, making the auction of space possible, but reducing the available “white spaces” (unused television band spectrum) between broadcasters, to the detriment of wireless audio users (Steve Harvey’s excellent ongoing coverage of wireless audio issues continues on this month’s cover, with more online).
For large-scale productions, the current state of affairs is challenging but manageable. With the pending auctions, that may no longer be true. For smaller end-users, one migration, frequently requiring reinvestment, has already occurred (assuming these users even know anything about the changes—I know from personal experience that there are non-technical operators using older systems purchased prior to the digital television revolution that are operating in forbidden space).
From one perspective, wireless audio use has been that of a squatter, taking advantage of resources not allocated for their use. As long as wireless audio usage didn’t interfere with licensed users, it was largely ignored. This predominantly unlicensed use of the spectrum limited our industry’s voice when the changes began.
There has been laudable cooperation among competing microphone manufacturers, vigorously championing wireless audio use with the FCC.
Sennheiser, for example, submitted a recent Petition for Reconsideration with the FCC, lobbying that two protected blocks of clean spectrum be reserved for wireless audio use. Further, Sennheiser is advocating for compensation from the auction revenues for end-users who have to replace systems no longer allowed after the next round of auctions. The original deadline for comments on the current proposed rulemaking has passed, but with the delay of the next auction until next year, that may be extended. If so, the more voices heard from, the better (various manufacturers have online resources to keep you informed, such as this November update from Sennheiser: http://x.co/5lpBl).
I write this admittedly simplified overview of extremely complicated issues primarily for those who have not been closely following the changes in spectrum allocation and usage. Power users of more than 50 systems in regular use can and should apply for now available licenses and register their events. If you use, own or sell wireless microphones at all, it is imperative that you stay informed and that you get involved.