Scope of annex
This annex covers frequency bands and regulatory as well as informative parameters recommended for radio microphones, both hand-held and body-worn, (also referred to as wireless microphones or cordless microphones), in-ear monitors, Assistive Listening Devices (ALD) (also referred to as aids for the hearing impaired) and personal cordless audio devices. Whenever this Annex refers to radio microphones this also includes in-ear monitors.
Radio microphones are small, low power (typically 50 mW or less) transmitters designed to be worn on the body, or hand-held, for the transmission of sound. The receivers are tailored to specific uses and may range from small and portable to rack mounted modules as part of a multichannel system. ALD are specific radio microphone applications which capture an acoustic signal that is transmitted by radio to the hearing aid receivers.
It also covers Band II low power FM transmitters operating in the FM Broadcast band 87.5 MHz to 108 MHz are used for the provision of an RF link between a personal audio device, including mobile phone, and the in-car or home entertainment system.
Assistive Listening Systems (ALS) are for use by the hearing impaired in public spaces such as airports, railway stations, churches and theatres, where the transmitter is connected to the audio programme or public address system and the ALD receiver is worn by hearing-impaired users, or integrated into users’ hearing aids.
Frequency band limits for radio microphones should be regarded as tuning ranges within which a device can be designated to operate. In most cases, Appendix 3 indicates those parts of the range that are not available in individual countries but this does not apply to the broadcasting bands at 174-216 MHz and 470-862 MHz where national geographical and licensing restrictions are likely to exist and the national administration should be contacted.
The sub-bands below are intended for the following applications:
• ALD: sub-bands b), c1), c2), d), g);
• Radio microphones: sub-bands a1), e), f1), f3), f4), f5), f6), g),h1), h2), h3), j);
• Personal cordless audio devices: sub-band g);
• Band II low power FM transmitters: sub-band a2);
• ALS: sub-band i);
• Inductive loop systems intended to assist the hearing impaired: sub-bands a0).
Frequency Band | Power / Magnetic Field | Spectrum access and mitigation requirements | Modulation /occupied bandwidth | ECC/ERC Deliverable | Notes | |
---|---|---|---|---|---|---|
a0 | 100Hz - 9kHz |
120 dBµA/m at 10 m | No requirement | Not specified | Inductive loop systems intended to assist the hearing impaired. Antenna size of < 1/20 λ (see note 3) | |
a1 | 29.7MHz - 47MHz |
10 mW e.r.p. | No requirement | ≤ 50 kHz | Radio microphones. On a tuning range basis. Individual licence may be required | |
a2 | 87.5MHz - 108MHz |
50 nW e.r.p. | No requirement | ≤ 200 kHz | Band II low power FM transmitters (see note 4) | |
c1 | 169.4MHz - 169.475MHz |
500 mW e.r.p. | No requirement | Not specified | ECC/DEC/(05)02 | Assistive Listening Device (ALD) |
b | 169.4MHz - 174MHz |
10 mW e.r.p. | No requirement | Not specified | Assistive Listening Device (ALD). On a tuning range basis | |
c2 | 169.4875MHz - 169.5875MHz |
500 mW e.r.p. | No requirement | Not specified | ECC/DEC/(05)02 | Assistive Listening Device (ALD) |
d | 173.965MHz - 216MHz |
10 mW e.r.p. | See Notes 1 and 2 | Not specified | ECC Report 230 | Assistive Listening Device (ALD). On a tuning range basis. Individual licence may be required |
e | 174MHz - 216MHz |
50 mW e.r.p. | No requirement | Not specified | Radio microphones. On a tuning range basis. Individual licence may be required | |
f1 | 470MHz - 694MHz |
50 mW e.r.p. | No requirement | Not specified | Radio microphones. On a tuning range basis. Individual licence may be required | |
f5 | 694MHz - 703MHz |
50 mW e.r.p. | No requirement | Not specified | Radio microphones. On a tuning range basis. Individual licence may be required | |
f6 | 733MHz - 757.5MHz |
20 mW e.i.r.p. / 100 mW e.i.r.p. | No requirement | Not specified | Radio microphones. On a tuning range basis. Individual licence may be required. 100 mW restricted to body-worn equipment | |
f3 | 821.5MHz - 826MHz |
20 mW e.i.r.p. / 100 mW e.i.r.p. | No requirement | Not specified | Radio microphones. Individual licence may be required. 100 mW restricted to body-worn equipment | |
f4 | 826MHz - 832MHz |
100 mW e.i.r.p. | No requirement | Not specified | Radio microphones. Individual licence may be required | |
g | 863MHz - 865MHz |
10 mW e.r.p. | No requirement | Not specified | Radio microphones and personal cordless audio devices. The frequency band is also identified in Annex 1 | |
h1 | 1350MHz - 1400MHz |
20 mW e.i.r.p. / 50 mW e.i.r.p. | No requirement | Not specified | Radio microphones. Individual licence may be required. 50 mW restricted to body-worn equipment or equipment implementing Spectrum Scanning Procedure (SSP) | |
h2 | 1492MHz - 1518MHz |
50 mW e.i.r.p | No requirement | Not specified | Radio microphones. On a tuning range basis. Individual licence required. Restricted to indoor use | |
h3 | 1518MHz - 1525MHz |
50 mW e.i.r.p. | No requirement | Not specified | Radio microphones. On a tuning range basis. Individual licence required. Restricted to indoor use | |
i | 1656.5MHz - 1660.5MHz |
2 mW/ 600 kHz e.i.r.p | No requirement | Not specified | ECC Report 270 | Assistive Listening Systems. Individual licence may be required. See conditions in ECC Report 270, annex 4 |
j | 1785MHz - 1805MHz |
20 mW e.i.r.p. / 50 mW e.i.r.p. | No requirement | Not specified | Radio microphones. Individual licence may be required. 50 mW restricted to body-worn equipment or equipment implementing Spectrum Scanning Procedure (SSP) |
Note 1 | A threshold of 35 dBµV/m is required to ensure the protection of a DAB receiver located at 1.5m from the ALD device, subject to DAB signal strength measurements taken around the ALD operating site. |
Note 2 | The ALD device should operate under all circumstances at least 300 kHz away from the channel edge of an occupied DAB channel. |
Harmonised Standards
EN 303 348 sub-band a0)
EN 300 422 all sub-bands except a2)
EN 301 357 sub-bands a2) and g)
Systems using ETSI EN 301 357 should be designed so that when not in use there should be no transmission of an RF carrier, where indicated in the frequency issues.
Technical parameters also referred to in the
harmonised standard
Note 3: Sub-band a0):
The antenna size is described by the distance between those two points on the antenna that have the largest distance between them (e.g. for a rectangle shaped antenna the largest diagonal; for a circular shaped antenna the diameter).
Note 4: Sub-band a2):
The user interface of SRD shall permit as a minimum the selection of any and all possible frequencies within the 88.1 MHz to 107.9 MHz and as a maximum 87.6 MHz to 107.9 MHz. When audio signals are not present, apparatus must employ a transmission time out facility. Pilot tones that ensure continuity of transmission are not permitted.
Frequency issues
Sub-band d):
ECC Report 230 provides information on ALD frequency issues in the frequency band 174-216 MHz including an example for an on-site measurement procedure. It should be noted that ALD applications may need to move in frequency if changes in the use of the broadcast radio service take place.
Sub-band h2):
This frequency band is identified for the introduction of mobile/fixed communication networks supplemental downlink (MFCN SDL) in ECC Decision (17)06. National administrations may authorise radio microphones in the band as long as they will not have introduced mobile/fixed communication networks (MFCN).