FCC Issues New Findings for Users of Wireless Microphone Systems

Two documents issued by the FCC on June 2 provide some reason for optimism on the part of licensed–wireless-microphone users. However, the professional audio community, which has been lobbying hard for protection of their diminishing wireless turf in the face of ongoing spectrum auctions, didn’t get everything they wished for.

Key points from the First and Second Report & Orders, pertaining to the Incentive Auction planned by the FCC and its impact on the wireless-microphone–user base, respectively, reveal that the government agency has accommodated professional users to a significant extent, particularly by extending licensing eligibility to sound companies and performance venues that routinely use 50 or more wireless microphones and allowing the use of licensed wireless mics as little as 4 km from the service contours of existing broadcasters, even shorter distances if users and broadcasters can coordinate frequencies and times, far less than the previous 70-mile limitations that had been in place.

On the other hand, rules regarding the use of the guard bands and duplex gap (sometimes called the mid-band gap) of the 600 MHz band remain ambiguous. Duplex-gap operation may be limited to broadcasters and cable-programming networks, for coverage of breaking news.

However, Joe Ciaudelli, U.S. spectrum correspondent for Sennheiser, points out, “the relevant paragraph said that wireless microphones in the duplex gap can seek protection on an as-needed basis, but you never know when breaking news is going to break. It implies a known time and place for spontaneity. This is going to require more clarification.”

The lower guard band will be shared with mics and TV White Space devices. “That guard band,” he adds, “has the potential to be a real wild west.”

Some of the findings will require further refinement. For instance, wireless microphones will be allowed to operate as they do today during the post-auction repacking process, a benefit that was not granted when the 700 MHz band was reallocated four years ago. Ciaudelli points out that parts of that range still lay fallow in some areas of the country, and allowing ongoing use during the repacking process is efficient.

Some Ambiguity
However, during that 39-month post-auction period, winners of the spectrum will also be able to use it for anything from a periodic test to 24/7 full-on service. “Those auction winners will have to provide a 120-day notice of commencement of service,” says Ciaudelli. “If a channel is subject to random testing prior to commencement of service to the public, it makes that space a volatile one and thus could undermine a smooth transition phase.”

Other areas of concern are the loss of two channels reserved exclusively for wireless microphones. Although one White Space channel (a channel not used for TV broadcast) will exist in every area of the U.S., available for shared use by both microphones and TV White Space devices, Ciaudelli says the loss of two full channels is significant: “Those channels were real safe havens for wireless users.”

However, the FCC also promised improvements in the TV bands’ database, which may in the future enable more-effective registration on shorter notice of wireless-microphone operators seeking interference protection from operation of TV White Space devices.

No Compensation
An important point that wireless-microphone manufacturers and owners had advocated — a mechanism for reimbursement to relocate mics rendered obsolete by TV-band repacking — was rejected by the FCC. Some observers consider the idea of compensation to be a bit of a Hail Mary pass, but Ciaudelli says that manufacturers plan to file a request for reconsideration on the grounds the FCC relied on the Spectrum Act, which authorizes reimbursement only to full-power TV stations involuntarily relocated to another channel, for their broadcast-transmission equipment.

“We did not invoke the Spectrum Act in our petition but rather the Title III provisions the commission relied on to require reimbursement following previous auctions,” he explains. “We will continue to pursue this cause so that the FCC can make an informed decision. Wireless-microphone owners, complying with a previous mandate by the commission, replaced all their 700-MHz equipment just a few years ago. Another major compulsory mic-equipment replacement would equate to a subsidy to the auction winners and cause a disproportionate burden on mic owners.”

Small users of unlicensed wireless microphones, such as houses of worship and K-12 sports organizations, will be pleased to learn that the FCC has continued in force the present waiver that allows unlicensed microphones to operate at 50 mW or less.

But what Ciaudelli finds most heartening was the FCC’s stated commitment “to accommodate the longer-term needs of wireless-microphone users through use of additional frequency bands to meet their varying needs.”

“This is very good news,” he says. “It shows that they recognize the importance of wireless microphones used in production and that the loss of spectrum is a serious issue. We will continue to work with the FCC on this point and hope to provide more details later in this year.”

According to Ciaudelli, wireless-systems manufacturers would work with the FCC’s Office of Engineering & Technology to identify spectrum areas that could be made available for wireless-microphone users and peacefully coexist with the incumbent entity occupying it. Overall, he adds, the R&Os were a mixed bag but with some tangible benefits for professional wireless users: “We have made progress, especially in terms of license expansion for true professional mic operators. I’m confident about the long-term future. The devil will be in the details of the transition period.”

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