Goto Section: 25.203 | 25.205 | Table of Contents
FCC 25.204
Revised as of October 2, 2015
Goto Year:2014 |
2016
§ 25.204 Power limits for earth stations.
(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 θ ≤0°
+ 40 + 3θ dBW in any 4 kHz band for 0° <θ ≤5°
where θ 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 radiocommunication 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 θ ≤0°
+ 64 + 3 θ dBW in any 1 MHz band for 0° <θ ≤5°
where θ is as defined in paragraph (a) of this section.
(c) For angles of elevation of the horizon greater than 5° 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) To the extent specified in paragraphs (e)(1) through (e)(4) of this
section, earth stations in the Fixed-Satellite Service may employ uplink
adaptive power control or other methods of fade compensation to facilitate
transmission of uplinks at power levels required for desired link
performance while minimizing interference between networks.
(1) Except when paragraphs (e)(2) through (e)(4) of this section apply,
transmissions from FSS earth stations in frequencies above 10 GHz may exceed
the uplink EIRP and EIRP density limits specified in the station
authorization under 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. EIRP levels must be
returned to normal as soon as the attenuating weather pattern subsides. The
maximum power level for power control purposes must be coordinated with
adjacent satellite operators.
(2) An FSS earth station transmitting to a geostationary space station in
the 13.77-13.78 GHz band must not generate more than 71 dBW EIRP in any 6
MHz band. An FSS earth station transmitting to a non-geostationary space
station in the 13.77-13.78 GHz band must not generate more than 51 dBW EIRP
in any 6 MHz band. Automatic power control may be used to increase the EIRP
density in a 6 MHz uplink band in this frequency range to compensate for
rain fade, provided that the power flux-density at the space station does
not exceed the value that would result when transmitting with an EIRP of 71
dBW or 51 dBW, as appropriate, in that 6 MHz band in clear-sky conditions.
(3) FSS earth stations transmitting to geostationary space stations in the
28.35-28.6 GHz and/or 29.25-30.0 GHz bands may employ uplink adaptive power
control or other methods of fade compensation. For stations employing uplink
power control, the values in paragraphs (a)(1), (a)(2), and (a)(4) of
§ 25.138 may be exceeded by up to 20 dB under conditions of uplink fading due
to precipitation. The amount of such increase in excess of the actual amount
of monitored excess attenuation over clear sky propagation conditions must
not exceed 1.5 dB or 15 percent of the actual amount of monitored excess
attenuation in dB, whichever is larger, with a confidence level of 90
percent except over transient periods accounting for no more than 0.5
percent of the time during which the excess is no more than 4.0 dB.
(4) Transmissions in the 24.75-25.25 GHz band from 17/24 GHz BSS feeder-link
earth stations employing power control may exceed the values in paragraphs
(b)(1), (b)(2), and (b)(4) of § 25.223 by up to 20 dB under conditions of
uplink fading due to precipitation. The amount of such increase in excess of
the actual amount of monitored excess attenuation over clear sky propagation
conditions must not exceed 1.5 dB or 15 percent of the actual amount of
monitored excess attenuation in dB, whichever is larger, with a confidence
level of 90 percent except over transient periods accounting for no more
than 0.5 percent of the time during which the excess is no more than 4.0 dB.
(f) An earth station in the Fixed-Satellite Service transmitting in the
13.75-14 GHz band must have a minimum antenna diameter of 4.5 m, and the
EIRP of any emission in that band should be at least 68 dBW and should not
exceed 85 dBW.
(g) [Reserved]
(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; 79 FR 8322 , Feb. 12, 2004]
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Goto Section: 25.203 | 25.205
Goto Year: 2014 |
2016
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