Normally, operations licensed under this part are intended to provide intrastation mobile communications. For example, a base station is intended to communicate with its associated mobile stations and mobile stations are intended to communicate between associated mobile stations and associated base stations of the licensee. Accordingly, operations between base stations at fixed locations are permitted only in the following situations:
(a) Base stations licensed under subpart T of this part and those in the Public Safety Pool that operate on frequencies below 450 MHz, may communicate on a secondary basis with other base stations, operational fixed stations, or fixed receivers authorized in these services or pools.(b) Base stations licensed on any frequency in the Industrial/Business Pool and on base stations frequencies above 450 MHz in the Public Safety Pool may communicate on a secondary basis with other base stations, operational fixed stations, or fixed receivers authorized in these pools only when: (1) The messages to be transmitted are of immediate importance to mobile stations; or(2) Wireline communications facilities between such points are inoperative, economically impracticable, or unavailable from communications common carrier sources. Temporary unavailability due to a busy wireline circuit is not considered to be within the provisions of this paragraph.(c) Operational fixed stations may communicate with units of associated mobile stations only on a secondary basis.(d) Operational fixed stations licensed in the Industrial/Business Pool may communicate on a secondary basis with associated base stations licensed in these services when: (1) The messages to be transmitted are of immediate importance to mobile stations; or(2) Wireline communications facilities between such points are inoperative, economically impracticable, or unavailable from communications common carrier sources. Temporary unavailability due to a busy wireline circuit is not considered to be within the provisions of this paragraph.(e) Travelers' Information Stations are authorized to transmit certain information to members of the traveling public (see § 90.242 ).(f) CMRS licensees in the SMR categories of part 90, subpart S, CMRS providers authorized in the 220 MHz service of part 90, subpart T, CMRS paging operations as defined by part 90, subpart P and for-profit interconnected business radio services with eligibility defined by § 90.35 are permitted to utilize their assigned spectrum for fixed services on a co-primary basis with their mobile operations.61 FR 45356, Aug. 29, 1996, as amended at 62 FR 18933, Apr. 17, 1997; 72 FR 35199 , June 27, 2007