Sec. 25.210  Technical requirements for space stations in the Fixed-
          Satellite Service.

    (a) All space stations in the Fixed-Satellite Service used for 
domestic service in the 4/6 GHz frequency band shall:
    (1) Use orthogonal linear polarization with one of the planes 
defined by the equatorial plane;
    (2) Be designed so that the polarization sense of uplink 
transmissions is opposite to that of downlink transmissions on the same 
transponder; and
    (3) Shall be capable of switching polarization sense upon ground 
command.
    (b) All space stations in the Fixed-Satellite Service shall have a 
minimum capability to change transponder saturation flux densities by 
ground command in 4 dB steps over a range of 12 dB.
    (c) All space stations in the Fixed-Satellite Service shall be 
designed to

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derive the maximum capacity feasible from the assigned orbital location. 
In particular, space stations in the Fixed-Satellite Service are 
required to employ state-of-the-art full frequency re-use using both 
horizontal and vertical polarization.
    (d) For fixed-satellite space stations providing domestic service, 
full frequency re-use is defined as re-use of the frequency bands by 
polarization discrimination in both the uplink and downlink directions 
using state-of-the-art equipment and techniques.
    (e) For fixed-satellite space stations providing international 
service, full frequency re-use is defined as follows:
    (1) Satellites must employ polarization discrimination so that, 
through the use of dual polarization, they shall be able to reuse both 
the uplink and downlink frequency band assignments.
    (2) Satellites must be configured so that all assigned frequencies 
(in both polarizations) could be reused in beams serving widely separate 
areas.
    (f)  [Reserved]
    (g) Space station antennas in the Fixed-Satellite Service must be 
designed to provide a cross-polarization isolation such that the ratio 
of the on axis co-polar gain to the cross-polar gain of the antenna in 
the assigned frequency band shall be at least 30 dB within its primary 
coverage area.
    (h) Space stations to be operated in the geostationary satellite 
orbit must be:
    (1) Designed with the capability of being maintained in orbit within 
0.05 deg. of their assigned orbital longitude,
    (2) Maintained in orbit at their assigned orbital longitude within 
the longitudinal tolerance specified by the Commission, and
    (3) The Commission may authorize operations at assigned orbital 
longitudes offset by 0.05 deg. or multiples thereof from the nominal 
orbital location specified in the station authorizations.
    (i) Antenna measurements of both co-polarized and cross-polarized 
performance must be made on all antennas employed by space stations both 
within the primary coverage area to facilitate coordination with other 
Commission space station licensees and outside the primary coverage area 
to facilitate international frequency coordination with other 
Administrations. The results of such measurements shall be submitted to 
the Commission within thirty days after preliminary in-orbit testing is 
completed.
    (j) All operators of space stations shall, on June 30 of each year, 
file a report with the International Bureau and the Commission's 
Columbia Operations Center in Columbia, Maryland, containing the 
following information current as of May 31 of that year:
    (1) Status of satellite construction and anticipated launch dates, 
including any major problems or delays encountered;
    (2) A listing of any non-scheduled transponder outages for more than 
thirty minutes and the cause(s) of such outages;
    (3) A detailed description of the utilization made of each 
transponder on each of the in-orbit satellites. This description should 
identify the total capacity or the percentage of time each transponder 
is actually used for transmission, and the amount of unused system 
capacity in the transponder. This information is not required for those 
transponders that are sold on a non-common carrier basis. In that case, 
operators should indicate the number of transponders sold on each in-
satellite orbit.
    (4) Identification of any transponders not available for service or 
otherwise not performing to specifications, the cause of these 
difficulties, and the date any transponder was taken out of service or 
the malfunction identified.
[ 58 FR 13420 , Mar. 11, 1993, as amended at  61 FR 9952 , Mar. 12, 1996;  62 FR 5931 , Feb. 10, 1997]