Regulatory Compliance News

FCC Issues Erratum Correcting Technical Standards for Wireless Microphones Under Parts 15 and 74

The Federal Communications Commission (FCC) Office of Engineering and Technology (OET) issued an Erratum under document reference DOC-406329A1, making critical technical corrections to the Report and Order (FCC 24-22) in ET Docket No. 21-115. The underlying proceeding modernized rules under 47 CFR Part 15 and Part 74, permitting next-generation Wireless Multichannel Audio Systems (WMAS) to operate across broadcast television bands, the 600 MHz guard band and duplex gap, and select higher-frequency operational bands. The administrative correction addresses cross-referencing errors and clarifies dynamic spectrum parameters to ensure testing laboratories, equipment manufacturers, and Telecommunications Certification Bodies (TCBs) apply precise technical thresholds during equipment authorization workflows.

WMAS technology significantly improves spectral efficiency by allowing multiple audio channels to operate over a single wideband channel, overcoming the bandwidth constraints of traditional narrowband wireless microphones. The updated regulatory framework incorporates European Telecommunications Standards Institute (ETSI) standards—specifically ETSI EN 300 422-1—into FCC technical rules to govern power limits, out-of-band emissions (OOBE), and channelization for professional audio equipment. By releasing DOC-406329A1, the Commission rectified administrative inaccuracies across rule text modifications affecting Part 15 subpart C and Part 74 subpart H, ensuring that laboratory test procedures for broad-bandwidth microphones align with published Federal Register codifications.

This regulatory action holds key compliance implications for audio equipment manufacturers, testing facilities, and spectrum managers utilizing LPAS (Low Power Auxiliary Station) allocations. Compliance managers preparing technical construction files for FCC Certification must ensure that laboratory test reports accurately reflect the corrected rule text and referenced ETSI measurement methodologies. Maintaining strict alignment with these corrected Part 15 and Part 74 operational parameters guarantees that advanced WMAS equipment and high-density wireless microphone installations can secure equipment authorization while mitigating potential interference risks to primary broadcast and mobile broadband operations.