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 [thetas]: 0[deg]
+40+3 [thetas] dBW in any 4 KHz band for [thetas]<0[deg][lE]05[deg]


where [thetas] 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 [thetas]<0[deg]
+64+3 [thetas] dBW in any 1 MHz band for 0[deg]<[alpha]<5[deg]


where [thetas] is as defined in paragraph (a) of this section.
    (c) For angles of elevation of the horizon greater than 5[deg] there 
shall be no restriction as to the equivalent isotropically radiated 
power transmitted by an earth station towards the horizon.
    (d) Notwithstanding the e.i.r.p. and e.i.r.p. density limits 
specified in the station authorization, each earth station transmission 
shall be conducted at the lowest power level that will provide the 
required signal quality as indicated in the application and further 
amended by coordination agreements.
    (e) For operations at frequencies above 10 GHz, earth station 
operators may exceed the uplink e.i.r.p. and e.i.r.p. density limits 
specified in the station authorization under the conditions of uplink 
fading due to precipitation by an amount not to exceed 1 dB above the 
actual amount of monitored excess attenuation over clear sky propagation 
conditions. The e.i.r.p. levels shall be returned to normal as soon as 
the attenuating weather pattern subsides. The maximum power level for 
power control purposes shall be coordinated between and among adjacent 
satellite operators.
    (f) In the band 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

[[Page 328]]

the level of mutual interference between networks.

[ 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]