1、 Rec. ITU-R F.1502 1 RECOMMENDATION ITU-R F.1502*PROTECTION OF THE FIXED SERVICE IN THE FREQUENCY BAND 8 025-8 400 MHZ SHARING WITH GEOSTATIONARY-SATELLITE SYSTEMS OF THE EARTH EXPLORATION-SATELLITE SERVICE (SPACE-TO-EARTH) (Question ITU-R 113/9) (2000) Rec. ITU-R F.1502 The ITU Radiocommunication A
2、ssembly, considering a) that prior to WRC-97, the band 8 025-8 400 MHz was allocated to the Earth exploration-satellite service (EESS) (space-to-Earth) on a secondary basis in Regions 1 and 3, except for those countries listed in RR No. S5.464; b) that the power flux-density (pfd) limits given in Ta
3、ble S21-4 of RR Article S21 apply to emissions from space stations of the EESS (space-to-Earth); c) that, for those administrations where the secondary allocation applied before WRC-97, geostationary orbital avoidance was not required for the fixed service and, therefore, the pfd limits given in Tab
4、le S21-4 of the RR will give rise to excessive interference to the fixed service; d) that provisional pfd limits in RR No. S5.462A are lower than those shown in Table S21-4 of the RR to protect the fixed service; e) that the band 8 025-8 400 MHz is used extensively by the fixed service in accordance
5、 with ITU-R channel arrangements for the 8 GHz band (see Recommendation ITU-R F.386) and is also used by some countries for television outside broadcast applications; f) that it is expected that the main application for the EESS in this band is for non-geostationary satellites (non-GSO), however the
6、re may be some geostationary satellite (GSO) applications; g) that WRC-97, in its Resolution 124 (WRC-97), resolved to invite ITU-R to study, as a matter of urgency, the required pfd limits to be applied to space stations of GSO systems in the EESS (space-to-Earth) in the frequency band 8 025-8 400
7、MHz where orbital avoidance has not been implemented by the fixed service sharing the band, recommends 1 that, in the frequency band 8 025-8 400 MHz shared between GSO systems in the EESS (space-to-Earth) and radio-relay systems in the fixed service, the spectral pfd produced at the surface of the E
8、arth (Regions 1 and 3 only) by emissions from a satellite, for all conditions and methods of modulation, should not exceed (see Notes 1 and 2): 135 dB(W/m2) in any 1 MHz band for 0 5 135 + 0.5( 5) dB(W/m2) in any 1 MHz band for 5 25 125 dB(W/m2) in any 1 MHz band for 25 90 where is the angle of arri
9、val of the radio-frequency wave (degrees above the horizontal plane); 2 that the aforementioned limits relate to the pfd and angles of arrival which would be obtained under free-space propagation conditions. NOTE 1 The pfd limits in recommends 1 have been derived in response to the request stated in
10、 Resolution 124 (WRC-97) and are intended for consideration by a future world radiocommunication conference which may wish to use this Recommendation in order to replace the limits contained in RR No. S5.462A. For Region 2 and for non-GSO systems in Regions 1 and 3 in the band 8 025-8 400 MHz, the p
11、fd limits in Table S21-4 of the RR will continue to apply. _ *This Recommendation should be brought to the attention of Radiocommunication Study Group 7 (WP 7C). 2 Rec. ITU-R F.1502 NOTE 2 In deriving the pfd limits in recommends 1, consideration was given to the fact that many radio-relay systems in Regions 1 and 3 had been established before 1997 when GSO orbital avoidance was not required and, therefore, it was found that if the pfd limits given in Table S21-4 of the RR are applied without change, an excessive interference will be caused to radio-relay systems at low angles of arrival.
