Just about every industry uses wireless audio solutions in some capacity, whether it’s for conferences, performances, or studio recording. That means that the current changes in the bandwidth available to wireless microphones have a wide-reaching impact across industries.
Wireless microphones work on either a licensed or an unlicensed basis. Most of the time, wireless microphones use frequencies that fall under the TV band. In 2017, though, countries began limiting the frequencies that wireless microphone users could use.
Which wireless microphone frequencies are legal? What does this mean for the future? Those answers require more than a list of legal wireless microphone frequencies. The more complete answer is that wireless microphones cannot use the 600 MHz band, albeit with a few exceptions.
Those exceptions permit some people to use wireless microphones on select frequencies and if it’s secondary use. Also, additional bands will be made available as the 600 MHz band is transitioned over to mobile broadband and emergency services.
Let’s break it down a bit more.
600 MHz Band and Wireless Microphones
A wireless microphone transmits sound without a cable. Broadcasters, news crews, stage performers, churches, and conference centers are just a few of the venues that rely on these microphones. The quality ranges according to the intended use.
Consumer wireless microphones have short-range applications, usually more than 100 meters. These microphones are license-exempt frequency bands like VHF and UHF. The ranges are 902-928 MHz, They also span 2.4 GHz, along with 5.8 GHz.
Why Is the ISED and the FCC Repurposing the 600 MHz Band?
Beginning in 2014, international discussion began about repurposing the 600 MHz band. Why is this happening? It’s because the band is now reserved for wireless services as well as public safety use. Mobile broadband includes bandwidth for smartphones.
Interference with Wireless Services
Wireless microphones that use the 600 MHz band interfere with these newly-repurposed licenses. Thus, wireless microphones must cease operation. Production of microphones in the 600 MHz band reduced as a result.
Joint Decision by ISED and the FCC
In 2015, ISED Canada and the United States’ FCC issued a joint decision to repurpose the 600 MHz band. This decision impacted wireless microphones that operated within that frequency range.
Both the US and Canada adopted a plan to transition devices like wireless microphones off the 600 MHz band. They did so because wireless microphones will interfere with mobile broadband systems when both are within the same frequency range. Thus, wireless microphones must move to other frequencies.
Transitioning Wireless Microphones
Beginning in 2017, the amount of band spectrum that can be available to microphones started to decrease. Frequencies between 614-698 MHz were repurposed for wireless services. Wireless microphones can no longer access these frequencies.
By July 13, 2020, all wireless microphones that operate between the 617-652 MHz/663-698 MHz frequencies will cease. Wireless microphone use will be available at frequencies below 608 MHz. They will also be available between 614-616 MHz, as well as the 653-663 MHz frequencies.
The following list is a few examples of popular wireless microphone systems by brand that are within the legal frequency band:
- Shure BLX24/PG58
- Shure BLX24/SM58
- Shure GLXD24/B87A
- Shure BLX1288/ Dual CVL/PG58
- Audio-Technica System 10 ATW-1102
- Audio-Technica System 10 ATW-1101/L
- TONOR UHF Wireless Microphone TW-820
US Authorized Frequencies
In the US, the FCC permits wireless microphones to be used in two ways, as licensed as well as unlicensed. Though, it depends on the frequency band. Most wireless microphones sold in the US use a spectrum in the UHF and VHF bands, or channels 2-51, with the exception of channel 37.
Unlicensed Operations
One can also operate a wireless microphone as a co-primary with one or more broadcasting auxiliary services, as long as it’s between 944-952 MHz. And, it must be limited to broadcast networks.
Licensed Operations
After July 13, 2020, you cannot operate a wireless microphone if it’s in the 600 MHz band, except within the ranges previously listed. The FCC made additional spectrum available for licensed wireless operations. These include the 169-172 range. It also includes part of the 900 band, 1435-1525 band. And, it includes the 6875-7125 band.
Secondary Operations
The FCC permits wireless microphones between 941.5-952 MHz, 952.85-956.25 MHz, and 956.45-959.85 MHz. It also permits it between 6875-6900 and 7100-7125 MHz bands. Though, this is only available to broadcasters, movie and television productions, and sound companies. Further, microphone use must be secondary. And, they cannot interfere with primary users.
Canadian Authorized Frequencies
In Canada, wireless microphones with the 26.10-26.48 MHz bands, 88-107.5, 150-174, 450-451, and the 455-456 MHz bands are stable. ISED states that these do not cause interference issues.
License-Exempt Use
License-exempt use of the bands that fall between 902-928, 2400-2483.5, and 5725-5850 MHz is permitted. It includes common consumer applications like RLAN. Wi‑Fi, Bluetooth, for example, fall under the RLAN category. Operation within these bands does not generate interference with other devices.
If license-exempt wireless microphones operate in UHF, they can operate on unused TV channels. Though, they will not be protected from interference. Users can obtain a license in order to receive some interference protection.
Licensed Wireless Microphones
There are about 75 people in Canada who hold 450 wireless microphone licenses. These licenses are for microphones that work in the VHF/UHF broadcasting bands. Canadians register about 100 wireless microphones every year. Most of these are short‑term, not lasting more than a few weeks. The majority of the wireless microphones are license‑exempt
Impacts of Repurposing the 600 MHz Band
Due to the repurposing the 600 MHz band, people who use wireless microphones will be impacted as the transition reduced the spectrum that will be available. Further, existing TV stations will have to move from above 614 MHz to below 608 MHz.
On top of that, the band 608-614 MHz is dedicated to radio astronomy services, so it is unavailable. As broadcasting stations make the transition to the lower frequencies, less spectrum is open for wireless microphone users.
New Frequencies for Future Generations of Wireless Microphones
The FCC and ISED are considering making new spectrum available to wireless microphones. The range is between 941-960, 6930-6955, and 7100-7125 MHz frequency bands. This spectrum is for secondary microphone use only. These will be the newest legal wireless microphone frequencies.
Further, the two countries are doing so in partnership with the United Kingdom and other countries to create a common industry standard.
Canada and the US have similar incumbent services that can operate within these frequency bands. These are compatible with the frequencies and wireless microphones manufactured in other countries. Thus, there are many possibilities for wireless microphone development and operation in the future. (Those opportunities will be for secondary use.)