Sec.  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 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: 0°

   +40+3 TH dBW in any 4 KHz band for TH<0°=<05°

   where TH is the angle of elevation of the horizon viewed from the
   center of radiation of the antenna of the earth station and measured
   in degrees as positive above the horizontal plane and negative below
   it.

   (b) 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 operating in
   frequency bands above 15 GHz shall not exceed the following limits
   except as provided for in paragraph (c) of this section:

   +64 dBW in any 1 MHz band for TH<0°

   +64+3 TH dBW in any 1 MHz band for 0°13.75-14 GHz, an earth station in the fixed-satellite
   service shall have a minimum antenna diameter of 4.5 m and the
   e.i.r.p. of any emission should be at least 68 dBW and should not
   exceed 85 dBW. The e.i.r.p. density of emissions from any earth
   station in the FSS operating with a space station in
   geostationary-satellite orbit shall not exceed 71 dBW in any 6 MHz
   band from 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 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 Sec. 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.

   [ 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]