§  25.210   Technical requirements for space stations.

   (a)-(b) [Reserved]

   (c) Space station antennas operating in the Direct Broadcast Satellite
   Service or operating in the Fixed-Satellite Service for reception of
   feeder links for Direct Broadcast 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 is at least 27 dB within the primary coverage
   area.

   (d)-(e) [Reserved]

   (f) All space stations in the Fixed-Satellite Service operating in any
   portion of the 3600-4200 MHz, 5091-5250 MHz, 5850-7025 MHz, 10.7-12.7
   GHz, 12.75-13.25 GHz, 13.75-14.5 GHz, 15.43-15.63 GHz, 18.3-20.2 GHz,
   24.75-25.25 GHz, or 27.5-30.0 GHz bands, including feeder links for
   other space services, and in the Broadcasting-Satellite Service in the
   17.3-17.8 GHz band (space-to-Earth), shall employ state-of-the-art full
   frequency reuse, either through the use of orthogonal polarizations
   within the same beam and/or the use of spatially independent beams.
   This requirement does not apply to telemetry, tracking, and command
   operation.

   (g)-(h) [Reserved]

   (i) 17/24 GHz BSS space station antennas transmitting in the 17.3-17.8
   GHz band 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 is at least 25 dB
   within its primary coverage area.

   (j) Space stations operated in the geostationary satellite orbit must
   be maintained within 0.05° of their assigned orbital longitude in the
   east/west direction, unless specifically authorized by the Commission
   to operate with a different longitudinal tolerance, and except as
   provided in Section 25.283(b) (End-of-life Disposal).

   [ 58 FR 13420 , Mar. 11, 1993, as amended at  61 FR 9952 , Mar. 12, 1996;
    62 FR 5931 , Feb. 10, 1997;  62 FR 61457 , Nov. 18, 1997;  68 FR 51508 ,
   Aug. 27, 2003;  69 FR 54587 , Sept. 9, 2004;  70 FR 32256 , June 2, 2005;
    72 FR 50029 , Aug. 29, 2007;  78 FR 8428 , Feb. 6, 2013;  79 FR 8323 , Feb.
   12, 2014;  81 FR 55338 , Aug. 18, 2016;  83 FR 34491 , July 20, 2018]