The FCC is diving into wireless multichannel audio systems (WMAS), an emerging wireless microphone technology designed to enable more microphones per megahertz of spectrum.
The commission has officially adopted a Notice of Proposed Rulemaking that is seeking public comment on whether WMAS technology should be granted a licensed basis in frequency bands where wireless mics are already authorized. This includes TV bands, the 600 MHz duplex gap and in portions of the 900 MHz, 1.4 GHz and 7 GHz bands. The NPRM also looks at using WMAS on an unlicensed basis.
WMAS allows microphones to operate using wider bandwidth channels than FCC rules currently allow by digitally combining multiple mic signals. It also uses a more efficient operating protocol, resulting in a larger number of wireless mics being able to operate in the available spectrum.
Europe has already permitted the use of WMAS technology under the European Telecommunications Standards Institute standards.
The proposals are designed to amend the FCC’s Part 74 licensed radio device rules — known as low-power auxiliary station (LPAS) devices — to support efficient use of spectrum and implement interference protection standards. The proposal also seeks comment on whether the commission should permit WMAS to operate on an unlicensed basis under the FCC’s Part 15 rule.
Any changes are not intended to impact incumbent spectrum operations, the FCC claims.
“These [WMAS] systems have the potential to significantly improve the efficiency of wireless microphone operations,” said FCC Acting Chairwoman Jessica Rosenworcel. “So much so, that under the rules we propose here, three times as many microphones may be able to operate while putting the same amount of power over the air as a single wireless microphone does under our rules today.”
The NPRM was approved unanimously by the FCC during its April Open Commission Meeting.