47 CFR § 27.64 - Protection from interference.
Wireless Communications Service (WCS) stations operating in full accordance with applicable FCC rules and the terms and conditions of their authorizations are normally considered to be non-interfering. If the FCC determines, however, that interference which significantly interrupts or degrades a radio service is being caused, it may, after notice and an opportunity for a hearing, require modifications to any WCS station as necessary to eliminate such interference.
(a)Failure to operate as authorized. Any licensee causing interference to the service of other stations by failing to operate its station in full accordance with its authorization and applicable FCC rules shall discontinue all transmissions, except those necessary for the immediate safety of life or property, until it can bring its station into full compliance with the authorization and rules.
(b)Intermodulation interference. Licensees should attempt to resolve such interference by technical means.
(c)Situations in which no protection is afforded. Except as provided elsewhere in this part, no protection from interference is afforded in the following situations:
(1)Interference to base receivers from base or fixed transmitters. Licensees should attempt to resolve such interference by technical means or operating arrangements.
(2)Interference to mobile receivers from mobile transmitters. No protection is provided against mobile-to-mobile interference.
(3)Interference to base receivers from mobile transmitters. No protection is provided against mobile-to-base interference.
(4)Interference to fixed stations. Licensees should attempt to resolve such interference by technical means or operating arrangements.
(5)Anomalous or infrequent propagation modes. No protection is provided against interference caused by tropospheric and ionospheric propagation of signals.
(d)Harmful interference to SDARS operations requiring resolution. The following conditions will be presumed to constitute harmful interference to SDARS operations from WCS operations in the 2305-2320 MHz and 2345-2360 MHz bands and require WCS operators to work cooperatively with SDARS operators to address areas where such power levels are exceeded and harmful interference occurs:
(1) A WCS ground signal level greater than −44 dBm in the upper or lower A or B block, or −55 dBm in the C or D block, present at a location on a roadway, where a test demonstrates that SDARS service would be muted over a road distance of greater than 50 meters; or
(2) A WCS ground signal level exceeding −44 dBm in the upper or lower A or B block, or −55 dBm in the C or D block on a test drive route, which is mutually agreed upon by the WCS licensee and the SDARS licensee, for more than 1 percent of the cumulative surface road distance on that drive route, where a test demonstrates that SDARS service would be muted over a cumulative road distance of greater than 0.5 percent (incremental to any muting present prior to use of WCS frequencies in the area of that drive test).