Sec. 90.361  Interference from part 15 and Amateur operations.

    Operations authorized under parts 15 and 97 of this chapter may not 
cause harmful interference to LMS systems in the 902-928 MHz band. These 
operations will not be considered to be causing harmful interference to 
a multilateration LMS system operating in one of the three MTA sub-bands 
(see Sec. 90.357(a)) if they operate in accordance with the provisions 
of parts 15 or 97 of this chapter and at least one of the following 
conditions are met:
    (a) It is a field disturbance sensor operating under Sec. 15.245 of 
this chapter and it is not operating in the 904-909.750 or 919.750-
928.000 MHz sub-bands; or
    (b) It does not employ an outdoor antenna; or
    (c) If it does employ an outdoor antenna, then if:
    (1) The directional gain of the antenna does not exceed 6 dBi, or if 
the directional gain of the antenna exceeds 6 dBi, it reduces its 
transmitter output power below 1 watt by the proportional amount that 
the directional gain of the antenna exceeds 6 dBi; and
    (2) Either:
    (i) The antenna is 5 meters or less in height above ground; or
    (ii) The antenna is more than 5 meters in height above ground but 
less than or equal to 15 meters in height above ground and either:
    (A) Adjusts its transmitter output power below 1 watt by 20 log (h/
5) dB, where h is the height above ground of the antenna in meters; or
    (B) Is providing the final link for communications of entities 
eligible under subpart B or C of this part 90.