Sec.  90.425   Station identification.

   Stations licensed under this part shall transmit identification in
   accordance with the following provisions:

   (a) Identification procedure. Except as provided for in paragraphs (d) and
   (e) of this section, each station or system shall be identified by the
   transmission of the assigned call sign during each transmission or exchange
   of transmissions, or once each 15 minutes (30 minutes in the Public Safety
   Pool) during periods of continuous operation. The call sign shall be
   transmitted by voice in the English language or by International Morse Code
   in accordance with paragraph (b) of this section. If the station is
   employing either analog or digital voice scrambling, or non-voice emission,
   transmission of the required identification shall be in the unscrambled mode
   using A3E, F3E or G3E emission, or International Morse, with all encoding
   disabled. Permissible alternative identification procedures are as follows:

   (1) A mobile relay stations call sign may be used to identify the associated
   control and mobile stations, except in the Public Safety Pool where the
   stations operate on frequencies below 450 MHz. Alternatively, a base station
   (including a mobile relay station) which is controlled by radio may be
   identified by the transmission of the call sign of the station at which
   communications originate.

   (2) One or more fixed relay stations may be identified by the transmission
   of the call signs of the stations at which the communications originate.

   (3) When a mobile station transmits on a different frequency than its
   associated base station, the assigned call sign of either the mobile station
   or the base station may be transmitted. Further, a single mobile unit in the
   licensee's authorized geographic area of operation may transmit station
   identification on behalf of any other operating mobile units in the fleet.

   (4) Use of an identifier other than the assigned call sign. (i) In the
   Public Safety Pool, mobile units licensed to a governmental entity and which
   operate on frequencies above 30 MHz may use an identifier which contains, at
   a minimum, the name of the licensee if the licensee maintains at the station
   a list of the special identifiers to be used by the mobile units.

   (ii) In the Industrial/Business Pool, licensees may request the Commission's
   local Engineer-in-Charge to approve the use of special mobile unit
   identifiers in lieu of the assigned call sign. Such requests, however, will
   not be granted where it appears that harmful interference to international
   operations may be caused by stations below 50 MHz, or by stations operating
   in areas within 80 km (50 miles) of an international boundary, or where it
   appears that the proposed method of identification will not adequately
   distinguish the mobile units of the applicant from the mobile units of other
   licensees in the area.

   (iii) In the Industrial/Business Pool, railroad licensees (as defined in
    Sec. 90.7) may identify stations by the name of the railroad and the train
   number, caboose number, engine number, or the name of the fixed wayside
   station. If none of these forms are practicable, any similar name or number
   may be designated by the railroad concerned for use by its employees in the
   identification of fixed points or mobile units; Provided, That, a list of
   such identifiers is maintained by the railroad. An abbreviated name or the
   initials of the railroad may be used where such are in general usage. In
   those areas where it is shown that no difficulty would be encountered in
   identifying the transmission of a particular station (as, for example, where
   stations of one licensee are located in a yard isolated from other radio
   installations), approval may be given to a request from the licensee for
   permission to omit the station identification.

   (5) Use of identifiers in addition to assigned call signs. Nothing in this
   section shall be construed as prohibiting the transmission of station or
   unit identifiers which may be necessary or desirable for system operation,
   Provided, That, they are transmitted in addition to the assigned station
   call sign or other permissible form of identification.

   (b) Use of automatic Morse code identification equipment. Automatically
   activated equipment may be used to transmit station identification in
   International Morse Code pursuant to the following conditions:

   (1) The signal output of the automatic identification equipment shall be
   connected to the transmitter at the microphone input or any other
   manufacturer-provided signal input terminal and shall be adjusted to produce
   40 percent  ±10 percent of the maximum permissible modulation or deviation
   level. This adjustment shall be performed when all other modulating signals
   are absent.

   (2) The Morse code transmission rate shall be maintained between 20 and 25
   words per minute.

   (3) The frequency of the keyed tone comprising the identification signal
   shall be 1200  ±800 Hz. A licensee may be required to change the frequency in
   order to prevent interference to the operations of another co-channel
   licensee.

   (4) Should activation of automatic Morse code identification equipment
   interrupt the communications of another co-channel licensee, the Commission
   may require the use of equipment which will delay automatic station
   identification until such co-channel communications are completed.

   (c) Special provisions for identification in the Radiolocation Service. (1)
   Stations in the Radiolocation Service are not required to identify except
   upon specific instruction from the Commission or as required by paragraph
   (c)(2) of this section.

   (2) Stations in the Radiolocation Service operating on frequencies above
   3400 kHz that employ spread spectrum techniques shall transmit a two-letter
   manufacturer's designator, authorized by the Commission on the station
   authorization, at the beginning and ending of each transmission and once
   every 15 minutes during periods of continuing operation. The designator
   shall be transmitted in International Morse Code at a speed not exceeding 25
   words per minute, and the spread spectrum mode of operation shall be
   maintained while the designator is being transmitted. The identifying signal
   shall be clearly receivable in the demodulated audio of a narrow-band FM
   receiver.

   (d) General exemptions. A station need not transmit identification if:

   (1) It is a mobile station operating on the transmitting frequency of the
   associated base station.

   (2) It is a mobile station in the Public Safety Pool using F1E or G1E
   emission.

   (3) It is transmitting for telemetering purposes or for the activation of
   devices which are employed solely as a means of attracting attention, or for
   remote control purposes, or which is retransmitting by self-actuating means,
   a radio signal received from another radio station or stations.

   (4) It is any type of radiopositioning or radar station authorized in a
   service other than the Radiolocation Service.

   (5) It is used solely for automatic vehicle monitoring or location.

   (6) It is a paging station authorized in accordance with the provisions of
    Sec. 90.20(a)(2)(v).

   (7) It is a mobile station employing non-voice emissions and the associated
   base station identifies on behalf of the mobile unit(s).

   (8) It is a base or mobile station in the 220–222 MHz band authorized to
   operate on a nationwide basis in accordance with subpart T of this part.

   (9) It is a wireless microphone station operating in accordance with the
   provisions of  Sec. 90.265(b).

   (10) It is a Roadside Unit in a DSRCS system.

   (e) Special provisions for stations licensed under this part that are
   classified as CMRS providers under part 20 of this chapter.

   (1) Station identification will not be required for 929–930 MHz nationwide
   paging licensees or MTA or EA-based SMR licensees. All other CMRS stations
   will be required to comply with the station identification requirements of
   this paragraph.

   (2) CMRS stations subject to a station identification requirement will be
   permitted to use a single call sign for commonly owned facilities that are
   operated as part of a single system. The call sign must be transmitted each
   hour within five minutes of the hour, or upon completion of the first
   transmission after the hour.

   (3) CMRS stations granted exclusive channels may transmit their call signs
   digitally. The station licensee must provide the Commission with information
   sufficient to decode the digital transmission to ascertain the transmitted
   call sign.

   [ 43 FR 54791 , Nov. 22, 1978]

   Editorial Note:   For Federal Register citations affecting  Sec. 90.425, see the
   List of CFR Sections Affected, which appears in the Finding Aids section of
   the printed volume and on GPO Access.