Wireless microphones are used to transmit sound to an amplifier or recording device without needing a physical cable and serve the public interest through many important functions. For instance, wireless microphones enable broadcasters and other video programming networks to serve consumers, including helping electronic news gathering (ENG) activities in the field and broadcasting sports events. Wireless microphone users include theaters, music venues, film studios, conventions, corporate events, houses of worship, major sports leagues, and schools. Wireless microphones can be hand-held or body-worn.
There are a wide variety of wireless microphones available that serve different needs. Some meet high technical standards required for professional applications (such as those used for Broadway performances), while others do not require such high-end technical capabilities (such as those used for corporate events, or by schools). Other wireless devices such as in-ear monitors, can used for cueing on-air talent, or intercom systems for backstage communications.
The FCC allows the use of wireless microphones on a licensed and unlicensed basis, depending on the spectrum band, technical characteristics, and user eligibility. Most wireless microphones that operate today use spectrum in the TV bands – that is, the VHF and UHF bands allocated for television broadcasting – which includes TV channels 2-36. Wireless microphones also may operate on other spectrum bands as well. The technical rules under which wireless microphones operate will differ depending on the spectrum band in which they operate. Wireless microphones may be designed to operate on discrete frequencies within a spectrum band, or they may operate over a range of frequencies in band.
Changes beginning in 2017 concerning operation on 600 MHz frequencies. The amount of TV band spectrum available for wireless microphone has decreased because of the incentive auction, which was completed on April 13, 2017. Specifically, most (but not all) of the spectrum on TV channels 38-51 (614-698 MHz), has been repurposed for use by wireless services and will not continue to be available for wireless microphone use. Wireless microphones that operate in the 600 MHz service band (the 617-652 MHz and 663-698 MHz frequencies) were required to cease operation no later than July 13, 2020. See FCC 15-140. Spectrum will continue to be available for wireless microphone use on TV channels 2-36 (TV band frequencies that fall below 608 MHz), on portions of the 600 MHz guard band (the 614-616 MHz frequencies) and the 600 MHz duplex gap (the 653-663 MHz frequencies), and in various other spectrum bands outside of the TV bands. FCC 15-100, FCC 15-99.
Bands outside the TV bands for wireless microphone use. In 2015, the Commission provided for new opportunities for licensed wireless microphone operations in spectrum outside of the TV broadcast band, including in the 169-172 MHz band and portions of the 900 MHz band, the 1435-1525 MHz, and the 6875-7125 MHz bands. Unlicensed wireless microphone operations are permitted in several bands outside of the TV bands, including the 902-928 MHz band, the 1920-1930 MHz band, and portions of the 2.4 GHz and 5 GHz bands. See FCC 15-100.
Types of Wireless Microphone Operations
Licensed Wireless Microphones
Certain eligible wireless microphone users and users of other similar equipment (such as for cue and control communications and synchronization of TV camera signals) can obtain low power auxiliary station (LPAS) licenses under Part 74, Subpart H, of the FCC’s rules, to operate on TV band spectrum on a secondary basis subject to certain restrictions. See Part 74, Subpart H. The FCC’s rules generally permit licensed wireless microphones operations on unused television channels in the TV bands, but they must share this spectrum with other users and they only have secondary status (that is, they must protect the primary TV broadcast operations, as well as other primary and secondary operations, from harmful interference and must accept interference from these other users when operating). See FCC 15-100.
Wireless microphone users that are eligible for a Part 74 license historically have included broadcasters and motion picture and television program production entities. In 2014, the FCC added two new categories of eligible entities: “large venue owner or operators” and “professional sound companies”. To be eligible for a license under these new categories, an applicant must routinely use 50 or more LPAS devices (that is, uses 50 or more such devices for most events or productions), where the use of such devices is an integral part of major events or productions. See FCC 14-62.
Wireless microphone users may also operate on a licensed basis under Part 74 in other spectrum bands, including specified portions of the 900 MHz band, the 1435-1525 MHz band, and the 6875-7125 MHz band, where eligibility is limited generally to broadcasters, broadcast network entities, and large venue owners/operators or professional sound companies that routinely operate 50 or more wireless microphones for major events/productions. See Part 74, Subpart H Licensed wireless microphone users may also operate on specified frequencies in the 169-172 MHz Band, which is available to a variety of entities. See FCC 15-100.
The 941.5-944 MHz band is licensed on a primary basis for Private and Common Carrier Fixed Microwave services and to fixed Aural Broadcast Auxiliary Services. In addition, Federal fixed services also operate in this band on a co-primary basis. Since this band is shared between non-Federal and Federal, the Commission works directly with the National Telecommunications and Information Administration (NTIA) to coordinate the shared use of this band. The coordination process and specific filing requirements for operations in this band are explained in the Order on Reconsideration and Further Notice of Proposed Rulemaking, released July 14, 2017, starting at paragraph 73. See FCC 17-95.
Registration of Licensed Wireless Microphones Operations. The FCC’s rules protect licensed wireless microphone operations from unlicensed white space devices in the TV bands spectrum by permitting wireless microphone licensees to register their operations in a white spaces database (administered by third parties). Specifically, under the current rules, licensed wireless microphone users and licensed users of other LPAS equipment may register their operating locations, channels, and times in the white spaces database, and receive interference protection from unlicensed white space device operations.
Unlicensed Wireless Microphones
In 2015, the Commission established rules to allow unlicensed wireless microphones to operate in the TV band spectrum. See FCC 15-99. Many (if not most) wireless microphone users today operate on an unlicensed basis in the TV band spectrum. The unlicensed use of wireless microphones in TV band spectrum is subject to certain restrictions - including lower power levels than licensed operations, they may not cause harmful interference, and they must accept any interference from other users that operate in the band. In addition, unlicensed wireless microphones can operate on other frequency bands under the FCC’s Part 15 rules (e.g., the 902-928 MHz band, the 1920-1930 MHz band, and the 2.4 GHz band). See FCC 15-100.
Transition of Wireless Microphone Operations out of Certain Bands
Transition out of the 600 MHz Band
In 2014, the FCC adopted rules to implement the broadcast television spectrum incentive auction, which reorganized the existing television band and repurposed a portion of the UHF television band for wireless broadband services for 600 MHz service licensees. See FCC 14-50. As a result, spectrum in the 617-652 MHz and 663-698 MHz bands was repurposed for wireless licensees. See DA 17-314. The spectrum that is used by these 600 MHz service licensees are no longer available to wireless microphones as of July 13, 2020. In addition, wireless microphone operations must cease earlier if such operations could cause harmful interference to any 600 MHz service licensee’s operations. In particular, wireless microphone users must cease operation in frequencies in any areas where a 600 MHz service licensee has commenced operations or is conducting its first field application testing. See FCC 15-140.
The FCC provided for a transition period of up to 39 months to allow wireless microphone operators to obtain new equipment and transition out of the repurposed 600 MHz service band (617-652 MHz / 663-698 MHz). During the transition period, which ended on July 13, 2020, these operators could continue to access the spectrum that had been repurposed for 600 MHz service licensees under certain conditions. Specifically, wireless microphone users could operate on the 600 MHz service spectrum only if they did not cause harmful interference either to the existing broadcast television operations (which were also required to cease operating in the band no later than July 13, 2020) or to the 600 MHz service wireless licensees’ operations in the band. Wireless microphone users were also required to accept harmful interference from those broadcast television and 600 MHz service licensees. See FCC 15-100, FCC 15-99, FCC 15-140.
Wireless microphone users, whether licensed or unlicensed, may continue to operate on a secondary basis in the bands that continue to be available for, and used on a primary basis by, broadcast television (TV channels 2-36). Use of these TV band frequencies, which fall below 608 MHz, remain available for wireless microphone use. See FCC 15-100, FCC 15-99. Licensed wireless microphones may also operate on specific frequencies in the 600 MHz duplex gap (653-657 MHz), and unlicensed wireless microphones may operate on a portion of the 600 MHz guard band (614-616 MHz) and a portion of the 600 MHz duplex gap (657-663 MHz). See FCC 15-100, FCC 15-99.
Sale of 600 MHz band Wireless Microphones.
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 (617-652 MHz and 663-698 MHz) is now prohibited. See FCC 15-100, FCC 15-99, FCC 17-95, DA 17-709.
Transition out of the 700 MHz Band
In 2010, the FCC prohibited the operation of wireless microphones and similar devices (e.g., wireless intercoms, wireless in-ear monitors, wireless audio instrument links, and wireless cueing equipment) in the 700 MHz Band (i.e., 698 - 806 MHz). This 700 MHz band formerly had been allocated for TV broadcast services and has been repurposed for wireless broadband and public safety services. As a result, the use, manufacture, import, sale, lease, offer for sale or lease, or shipment of wireless microphones that are used in the 700 MHz Band was banned by the FCC. See FCC 10-16.
Reference Materials
- FCC 17-95 – Wireless Microphones Order on Reconsideration
- DA 17-314 – Closing and Channel Reassignment Public Notice
- FCC 15-140 – Commencing Operations Report and Order
- FCC 15-100 – Wireless Microphones Report and Order
- FCC 15-99 – TV Bands Part 15 R&O
- FCC 14-62 – TV Bands Wireless Microphones Second Report and Order
- FCC 14-50 – Incentive Auction Report and Order
- DA 10-92 – Consumer Disclosure Requirement for LPAS stations operating in the 698-806 MHz Band
- FCC 10-16 – Revised Rules for LPAS stations operating in the 698-806 MHz Band