Radio microphones

It is more than thirty years since radio microphones first appeared. Today they are in very widespread use in the audiovisual sector, as well as for conferences, public debates and concerts etc. Radio microphones give speakers and performers great freedom of movement. Generally low-power, they use different frequency bands. The use of such equipment is subject to the regulations on telecommunications.

 

Radiocommunications regulations

Radiocommunications regulations distinguish between radio applications that have a primary status in a specific frequency range and those with secondary status. Radio microphones fall into the category of radio applications with secondary status. Some frequency bands authorised for radio microphones are allocated to primary radio applications, such as broadcasting and mobile radiocommunications. More specifically, this means that radio microphones can only use the frequency gaps not used by primary radio applications. Secondary radio applications must meet a further requirement of not interfering with primary, priority radio applications. This means radio microphones do not have a right to reserved frequency resources nor do they enjoy a right to protection.

Today, despite the efforts at harmonisation in Europe, the frequency bands allocated to the use of radio microphones are very often subject to national restrictions. The European Radiocommunications Committee recommendation ERC/REC 70-03 concerning the use of short-range devices (SRD) mentions the national restrictions for the frequency bands available to radio microphones, together with the technical parameters, such as radiated power and the harmonised standards applicable in this area. 

 

Frequencies

For Switzerland, the usable frequencies are set out in the national frequency allocation plan (NFAP). The exact technical parameters, any restrictions and any licence obligations are indicated in the technical interface regulations (RIR).

The table below indicates the permitted power and the applicable technical interface regulations for each frequency band in which radio microphones can be operated without a licence:

 

 
Frequency band Maximum transit power Technical regulations Remarks

31.4 - 39.6 MHz

100 mW ERP

RIR1009-01

Use only in the channels indicated in RIR 1009-01

174 - 223 MHz

50 mW ERP

RIR1009-02

 

470 - 694 MHz 50 mW ERP RIR1009-10  
477 - 694 MHz 250 mW ERP RIR1009-11 Use only in the channels indicated in RIR 1009-11
823 - 826 MHz 20 mW EIRP
(ca. 12 mW ERP)
RIR1009-18 100 mW EIRP (ca. 60 mW ERP) for radio microphones carried on the body

826 - 832 MHz

100 mW EIRP
(ca. 60 mW ERP)

RIR1009-13

 

863 - 865 MHz

10 mW ERP

RIR1009-05

 

1350 - 1400 MHz 20 mW EIRP  RIR1009-20  Use possible from 01.01.2020. Use only within buildings. 50 mW EIRP for radio microphones carried on the body or with built-in Spectrum Scanning Procedure (SSP) 
1785 - 1804.8 MHz 20 mW EIRP
(ca. 12 mW ERP)
RIR1009-09 50 mW EIRP (ca. 30 mW ERP) for radio microphones carried on the body or with built-in Spectrum Scanning Procedure (SSP)

Notes:

  • Radio microphones can also operate in some other frequency bands.

For example, in the frequency ranges intended for non-specific short-range radio applications or in the frequency range for digital enhanced cordless telecommunications (DECT) at 1880 MHz. The technical interface regulations for the frequency ranges and radio parameters for non-specific applications are defined in RIR1008 and those for DECT in the 1880 MHz frequency range in RIR0503-01.

 

Frequency coordination for licence-exempted PMSE devices

The coordination of frequencies used by microphones, particularly at events where lots of microphones are used (e.g. concerts, exhibitions and press conferences etc.), is not carried out by OFCOM. The Office does not intervene in the event of interference caused by the simultaneous use of the same frequency by two or more radio microphones. It should be noted that completely interference-free operation is not guaranteed for the frequencies available to radio microphones. It is therefore the responsibility of the event organiser to commission specialist private companies or to let the various users on site reach agreement.

Users of licence-exempted PMSE devices can register on a voluntary basis in the database provided by a third party in order to coordinate frequency use at events. 

 

Placing on the market

Radio microphones are subject to compliance with the usual conditions for placing telecommunication equipment on the market: conformity assessment procedure successfully passed, compliance with the national frequency allocation plan, marking and user information.

When radio microphones equipped with frequency bands that are not permitted in Switzerland are placed on the market, the packaging must bear the indication of the applicable restriction in Switzerland. The restrictions must be set out precisely in the instructions for use (detailed information). This will avoid interference with other services.

 

Specialist staff
Last modification 09.01.2020

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