§  90.235   Secondary fixed signaling operations.

   Fixed operations may, subject to the following conditions, be
   authorized on a secondary basis for voice, tone or impulse signaling on
   a licensee's mobile service frequency(ies) above 25 MHz within the area
   normally covered by the licensee's mobile system. Voice signaling will
   be permitted only in the Public Safety Pool.

   (a) The bandwidth shall not exceed that authorized to the licensee for
   the primary operations on the frequency concerned.

   (b) The output power shall not exceed 30 watts at the remote site.

   (c) A1D, A2D, F1D, F2D, G1D and G2D emissions may be authorized. In the
   Police Radio Service, A3E, F1E, F2E, F3E, G1E, G2E, or G3E emissions
   may also be authorized.

   (d) Except for those systems covered under paragraph (e) of this
   section, the maximum duration of any non-voice signaling transmission
   shall not exceed 2 seconds and shall not be repeated more than 3 times.
   Signaling transmissions may be staggered at any interval or may be
   continuous. In the Public Safety Pool, the maximum duration of any
   voice signaling transmission shall not exceed 6 seconds and shall not
   be repeated more than 3 times.

   (e) Until December 31, 1999, for systems in the Public Safety Pool
   authorized prior to June 20, 1975, and Power and Petroleum licensees as
   defined in § 90.7 authorized prior to June 1, 1976, the maximum duration
   of any signaling transmission shall not exceed 6 seconds and shall not
   be repeated more than 5 times. For Power licensees authorized between
   June 1, 1976, and August 14, 1989, signaling duration shall not exceed
   2 seconds and shall not be repeated more than 5 times. Such systems
   include existing facilities and additional facilities which may be
   authorized as a clear and direct expansion of existing facilities.
   After December 31, 1999, all signaling systems shall be required to
   comply with the 2 second message duration and 3 message repetition
   requirements.

   (f) Systems employing automatic interrogation shall be limited to
   non-voice techniques and shall not be activated for this purpose more
   than 10 seconds out of any 60 second period. This 10 second timeframe
   includes both transmit and response times.

   (g) Automatic means shall be provided to deactivate the transmitter in
   the event the r.f. carrier remains on for a period in excess of 3
   minutes or if a transmission for the same signaling function is
   repeated consecutively more than five times.

   (h) Fixed stations authorized pursuant to the provisions of this
   section are exempt from the requirements of § § 90.137(b), 90.425, and
   90.429.

   (i) Base, mobile, or mobile relay stations may transmit secondary
   signaling transmissions to receivers at fixed locations subject to the
   conditions set forth in this section.

   (j) Under the provisions of this section, a mobile service frequency
   may not be used exclusively for secondary signaling.

   (k) The use of secondary signaling will not be considered in whole or
   in part as a justification for authorizing additional frequencies in a
   licensee's land mobile radio system.

   (l) Secondary fixed signaling operations conducted in accordance with
   the provisions of § § 90.317(a), 90.557 and 90.637 are exempt from the
   foregoing provisions of this section.

   [ 54 FR 28679 , July 7, 1989, as amended at  57 FR 34693 , Aug. 6, 1992;  58 FR 30996 , May 28, 1993;  60 FR 50123 , Sept. 28, 1995;  62 FR 18927 , Apr.
   17, 1997;  72 FR 35195 , June 27, 2007;  72 FR 44424 , Aug. 8, 2007;  79 FR 39339 , July 10, 2014]