Sec. 90.645  Permissible operations.

    Conventional and trunked radio systems may be used:
    (a) Only for purposes expressly allowed under this part.

[[Page 566]]

    (b) Only persons who are eligible for facilities, either under this 
subpart or in the radio service included under subparts B or C of this 
part.
    (c) Except for licensees classified as CMRS providers under part 20 
of this chapter, only for the transmission of messages or signals 
permitted in the services is which the participants are eligible.
    (d) For digital or analog transmissions.
    (e) An SMRS licensee or a licensee who has been authorized a 
channel(s) on an exclusive basis, may use the system for the 
transmission of any base/mobile message, page or signal permitted in the 
service in which the participants are eligible.
    (f) Where the channel(s) is assigned to an SMRS licensee or 
exclusively to a single licensee, or where all users of a system agree, 
more than a single emission may be utilized within the authorized 
bandwidth. In such cases, the frequency stability requirements of 
Sec. 90.213 shall not apply, but out-of-band emission limits of 
Sec. 90.209 shall be met.
    (g) Up to five (5) contiguous 806-821/851-866 band channels as 
listed in Secs. 90.615, 90.617, and 90.619 may be authorized after 
justification for systems requiring more than the normal single channel 
bandwidth. If necessary, licensees may trade channels amongst themselves 
in order to obtain contiguous frequencies. Notification of such proposed 
exchanges shall be made to the appropriate frequency coordinator(s) and 
to the Commission for approval.
    (h) Up to 10 contiguous 896-901/935-940 MHz band channels as listed 
in Sec. 90.617 may be combined for systems requiring more than the 
normal single channel bandwidth. If necessary, licensees may trade 
channels amongst themselves in order to obtain contiguous frequencies. 
Notification of such proposed exchanges shall be made to the appropriate 
frequency coordinator(s) and to the Commission for approval.
    (i) Paging operations may be utilized on multiple licensed 
facilities (community repeaters) only when all licensees of the facility 
agree to such use.
[ 47 FR 41032 , Sept. 16, 1982, as amended at  48 FR 51929 , Nov. 15, 1983; 
 51 FR 37405 , Oct. 22, 1986;  59 FR 59966 , Nov. 21, 1994;  62 FR 18935 , 
Apr. 17, 1997]

    Effective Date Note: At  62 FR 18935 , Apr. 17, 1997, Sec. 90.645 was 
amended by revising paragraph (b), effective Oct. 17, 1997.