§  25.204   Power limits.

   (a) In bands shared coequally with terrestrial radio communication
   services, the equivalent isotropically radiated power transmitted in
   any direction towards the horizon by an earth station, other than an
   ESV, operating in frequency bands between 1 and 15 GHz, shall not
   exceed the following limits except as provided for in paragraph (c) of
   this section:

   +40 dBW in any 4 kHz band for th <=0DEG

   +40 + 3th dBW in any 4 kHz band for 0DEG 13.77 to 13.78 GHz. The
   e.i.r.p. density of emissions from any earth station in the FSS
   operating with a space station in non-geostationary-satellite orbit
   shall not exceed 51 dBW in any 6 MHz band from 13.77 to 13.78 GHz.
   Automatic power control may be used to increase the e.i.r.p. density in
   the 6 MHz band in this frequency range to compensate for rain
   attenuation, to the extent that the power flux-density at the FSS space
   station does not exceed the value resulting from use by an earth
   station of an e.i.r.p. of 71 dBW or 51 dBW, as appropriate, in the 6
   MHz band in clear-sky conditions.

   (g) All earth stations in the Fixed-Satellite Service in the 20/30 GHz
   band, and feeder-link earth stations operating in the 24.75-25.25 GHz
   band (Earth-to-space) and providing service to geostationary satellites
   in the 17/24 GHz BSS, shall employ uplink adaptive power control or
   other methods of fade compensation such that the earth station
   transmissions shall be conducted at the power level required to meet
   the desired link performance while reducing the level of mutual
   interference between networks.

   (h) ESV transmissions in the 5925-6425 MHz (Earth-to-space) band shall
   not exceed an e.i.r.p. spectral density towards the radio-horizon of 17
   dBW/MHz, and shall not exceed an e.i.r.p. towards the radio-horizon of
   20.8 dBW. The ESV network shall shut-off the ESV transmitter if the
   e.i.r.p. spectral density towards the radio-horizon or e.i.r.p. towards
   the radio-horizon are exceeded.

   (i) Within 125 km of the TDRSS sites identified in §  25.222(d), ESV
   transmissions in the 14.0-14.2 GHz (Earth-to-space) band shall not
   exceed an e.i.r.p. spectral density towards the horizon of 12.5
   dBW/MHz, and shall not exceed an e.i.r.p. towards the horizon of 16.3
   dBW.

   (j) Within 125 km of the Tracking and Data Relay System Satellite
   (TDRSS) sites identified in §  25.226(c), VMES transmissions in the
   14.0-14.2 GHz (Earth-to-space) band shall not exceed an EIRP spectral
   density towards the horizon of 12.5 dBW/MHz, and shall not exceed an
   EIRP towards the horizon of 16.3 dBW.

   (k) Within radio line-of-sight of the Tracking and Data Relay System
   Satellite (TDRSS) sites identified in §  25.227(c), ESAA transmissions
   in the 14.0-14.2 GHz (Earth-to-space) band shall not exceed an EIRP
   spectral density towards or below the horizon of 12.5 dBW/MHz, and
   shall not exceed an EIRP towards or below the horizon of 16.3 dBW.

   [ 48 FR 40255 , Sept. 6, 1983, as amended at  58 FR 13420 , Mar. 11, 1993;
    61 FR 52307 , Oct. 7, 1996;  62 FR 61457 , Nov. 18, 1997;  66 FR 10623 ,
   Feb. 16, 2001;  70 FR 4784 , Jan. 31, 2005;  70 FR 32255 , June 2, 2005;  72 FR 50029 , Aug. 29, 2007;  74 FR 57098 , Nov. 4, 2009;  78 FR 8427 , Feb. 6,
   2013;  78 FR 14927 , Mar. 8, 2013]

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