The Spectrum Crunch Cometh

NEW YORK—Wireless audio equipment users will soon be facing a serious spectrum crunch. Having been moved out of the 700 MHz band during the 2010 DTV transition and now being required to vacate the 600 MHz band, wireless mic users can expect the 500 MHz band to be at least 20 percent more crowded, according to estimates.

In the Federal Communications Commission's Incentive Auction, which ended on April 13, 2017, major telecom companies including T-Mobile, Dish, Comcast and AT&T acquired licenses for much of the 600 MHz band. The initial auction rules suggested that wireless mic users might have up to three years to move out of the spectrum, but in some regions of the country they are already having to make way for the new 600 MHz services.

T-Mobile, which acquired the most spectrum in the 600 MHz service band (617-652 MHz and 663-698 MHz), has promised to fire up at least 10 MHz covering 1.2 million square miles by the end of 2017. Sites in Cheynne, Wyo., and near Portland, Maine, have already been lit up, and additional 600 MHz network sites are scheduled for Northwest Oregon, West Texas, Southwest Kansas, the Oklahoma panhandle, Western North Dakota, Coastal North Carolina, Central Pennsylvania, Central Virginia and Eastern Washington before year's end.

An Aug. 14, 2017, letter to wireless mic manufacturers and other relevant parties from Mark Bishop, T-Mobile's senior manager—spectrum management, requested that “all use of spectrum in the indicated channel blocks cease prior to Nov. 1, 2017.” The accompanying list of counties includes portions of major population centers such as Chicago, Phoenix, Dallas, Austin, San Francisco, Denver and Oklahoma City.

T-Mobile has partnered with PBS and its nationwide network to cover the costs for local public TV low-power facilities that must relocate in the spectrum repack and has also committed to providing financial assistance to any local TV stations that can move ahead of the FCC's three-year schedule. “We wish to minimize interference with the wireless base stations and handsets that will operate in the new band and we want to avoid disruptions to any operations currently in use,” stated Bishop.

The upshot? If you operate wireless microphone, in-ear monitor or comms systems, you need to familiarize yourself with the current FCC rules. You also need to remain vigilant regarding both progress of the planned three-year post-auction TV station repack in your market and the status of new 600 MHz band services, because you may have to vacate the spectrum sooner than expected.

Everyone should plan to vacate the 600 MHz band as soon as possible in any case and move to alternate available frequencies. The FCC has set a sunset date that prohibits “the manufacture, import, sale, lease, offer for sale or lease, or shipment of wireless microphones or similar devices intended for use in the United States that operate on the 600 MHz service band frequencies... after Oct. 13, 2018.”

Manufacturers including Audio-Technica, Sennheiser and Shure are offering rebate programs that allow users to trade-in 600 MHz equipment; terms and conditions vary from brand to brand. Alternatively, users of existing equipment operating in the spectrum from 470 MHz to 698 MHz may have it modified and recertified to comply with the FCC's new technical operating rules. Happily, the FCC listened to mic manufacturers and advocacy groups, including the SVG's DTV Audio Group, and also opened access to some additional spectrum, including portions of the 169-172 MHz band, the 900 MHz band, the 1435-1525 MHz band and the seven GHz band.

The bottom line is, now and going forward, you will need to mix and match spectrum, technologies and systems appropriately to your sources. Make equipment choices based on needs, not convenience. The gear you use indoors may be different to that used outdoors. Use wires wherever possible. Assign multiple comms belt packs to a single frequency.

Above all, if you meet the FCC criteria, get a license. If you do not have a license you will not be able to register in the databases for protection against white space devices and other equipment operating on your frequencies. An FCC Further Notice of Proposed Rulemaking suggests expanding licensing eligibility for certain venues and organizations that do not meet the current minimum threshold of “routinely using” 50 or more wireless mics, but no decision has yet been made.

The bad news is, this is not the end of the spectrum reshuffle. Microsoft is pushing the FCC for dedicated UHF frequencies to deliver its planned wireless services to rural America and the MOBILE NOW Act currently before Congress requires at least 255 MHz of federal and non-federal spectrum below 6 GHz be made available for mobile and fixed wireless broadband use by Dec. 31, 2020. 

For more information on the repack, visit TV Technology's repack silo.

Steve Harvey began writing for Pro Sound News and Surround Professional in 2000 and is currently senior content producer for Mix and a contributor to TV Tech. He has worked in the pro audio industry—as a touring musician, in live production, installed sound, and equipment sales and marketing—since November 1980.