Sec. 87.479  Harmful interference to radionavigation land stations.

    (a) Military or other Government stations have been authorized to 
establish wide-band systems using frequency-hopping spread spectrum 
techniques in the 960-1215 MHz band. Authorization for a Joint Tactical 
Information Distribution Systems (JTIDS) has been permitted on the basis 
of non-interference to the established aeronautical radionavigation 
service in this band. In order to accommodate the requirements for the 
system within the band, restrictions are imposed. Transmissions will be 
automatically prevented if:
    (1) The frequency-hopping mode fails to distribute the JTIDS 
spectrum uniformly across the band;
    (2) The radiated pulse varies from the specified width of 6.4 
microseconds &177;5%;
    (3) The energy radiated within &177;7 MHz of 1030 and 1090 
MHz exceeds a level of 60 dB below the peak of the JTIDS spectrum as 
measured in a 300 kHz bandwidth. The JTIDS will be prohibited from 
transmitting if the time slot duty factor exceeds a 20 percent duty 
factor for any single user and a 40 percent composite duty factor for 
all JTIDS emitters in a geographic area.
    (b) If radionavigation systems operating in the 960-1215 MHz band 
experience interference or unexplained loss of equipment performance, 
the situation must be reported immediately to the nearest office of the 
FAA, the National Telecommunications and Information Administration, 
Washington, DC 20504, or the nearest Federal Communications Commission 
field office. The following information must be provided to the extent 
available:
    (1) Name, call sign and category of station experiencing the 
interference;
    (2) Date and time of occurrence;
    (3) Geographical location at time of occurrence;
    (4) Frequency interfered with;
    (5) Nature of interference; and
    (6) Other particulars.