Sec.  90.647   Station identification.

   (a) Conventional systems of communication shall be identified in accordance
   with existing regulations governing such matters.

   (b) Trunked systems of communication, except as noted in paragraph (c) of
   this section, shall be identified through the use of an automatic device
   which transmits the call sign of the base station facility at 30 minute
   intervals. Such station identification shall be made on the lowest frequency
   in the base station trunk group assigned the licensee. Should this frequency
   be in use at the time station identification is required, such
   identification may be made at the termination of the communication in
   progress on this frequency. Identification may be made by voice or
   International Morse Code. When the call sign is transmitted in International
   Morse Code, it must be at a rate of between 15 to 20 words per minute and by
   means of tone modulation of the transmitter, the tone frequency being
   between 800 and 1000 hertz.

   (c) Stations operating in either the 806–824/851–869 MHz or 896–901/935–940
   MHz bands that are licensed on an exclusive basis, and normally employ
   digital signals for the transmission of data, text, control codes, or
   digitized voice may also be identified by digital transmission of the call
   sign. A licensee that identifies its station in this manner must provide the
   Commission, upon its request, information sufficient to decode the digital
   transmission and ascertain the call sign transmitted.

   (d) Notwithstanding the requirements set forth in this paragraph, systems
   operated by geographic area CMRS licensees are subject only to the station
   identification requirements of  Sec. 90.425(e).

   [ 47 FR 41032 , Sept. 16, 1982, as amended at  58 FR 12177 , Mar. 3, 1993;  65 FR 24420 , Apr. 26, 2000]