Sec. 90.637  Restrictions on operational fixed stations.

    (a) Except for control stations, operational fixed operations will 
not be authorized in the 806-824 MHz, 851-869 MHz, 896-901 MHz, or 935-
940 MHz bands. This does not preclude secondary fixed tone signaling and 
alarm operations authorized in Sec. 90.235 or in paragraph (c) of this 
section.
    (b) Control stations associated with one or more mobile relay 
stations will be authorized only on the assigned frequency of the 
associated mobile station. Use of a mobile service frequency by a 
control station of a mobile relay system is subject to the condition 
that harmful interference shall not be caused to stations of licensees 
authorized to use the frequency for mobile service communications.
    (c) Trunked and conventional systems that have exclusive-use status 
in their respective geographic areas may conduct fixed ancillary 
signaling and data transmissions subject to the following requirements:
    (1) All operations must be on a secondary, non-interference basis to 
the primary mobile operation of any other licensee.
    (2) The output power at the remote site must not exceed 30 watts.
    (3) Any fixed transmitters will not count toward meeting the mobile 
loading requirements nor be considered in whole or in part as a 
justification for authorizing additional frequencies in the licensee's 
mobile system.
    (4) Automatic means must be provided to deactivate the remote 
transmitter in the event the carrier remains on for a period in excess 
of three minutes.
    (5) Operational fixed stations authorized pursuant to the provisions 
of paragraphs (c) and (d) of this section are exempt from the 
requirements of Secs. 90.425 and 90.429.
    (d) Conventional systems that do not have exclusive-use status in 
their respective geographic areas may conduct fixed ancillary signaling 
and data transmissions only in accordance with all the provisions of 
Sec. 90.235.
[47 1997 FR 41032 , Sept. 16, 1982, as amended at  48 FR 51929 , Nov. 15, 1983; 
 49 FR 36377 , Sept. 17, 1984;  51 FR 37405 , Oct. 22, 1986;  52 FR 1332 , 
Jan. 13, 1987;  53 FR 12157 , Apr. 13, 1988;  57 FR 34693 , Aug. 6, 1992]