1、72 = 4855212 053bbO1 71 Rec. ITU-R SA.1161-1 RECOMMENDATION ITU-R SA. 1 16 1 - 1 SHARING AND COORDINATION CRITERIA FOR DATA DISSEMINATION AND DIRECT DATA READOUT SYSTEMS IN THE EARTH EXPLORATION-SATELLITE AND METEOROLOGICAL-SATELLITE SERVICES USING SATELLITES IN GEOSTATIONARY ORBIT (Question ITU-R 1
2、41/7) (1995-1999) The ITU Radiocommunication Assembly, considering a) satellite (MetSat) service may be shared by several systems, including those operating in other services; that the frequency bands allocated to the Earth exploration-satellite service (EESS) and the meteorological- b) criteria; th
3、at Recommendation ITU-R SA. 1 160 specifies the interference criteria needed to determine the sharing c that the sharing criteria may be determined using the methodology described in Recommen- dation ITU-R SA. 1023; d) that the typical deployment of interfering stations may change over a period of y
4、ears as a result of growth in the number of systems and revisions to frequency band allocations that are adopted by world radiocommunication conferences; e) that by governing the use of the radio-frequency spectrum in their territory and through international coordination of fiequency assignments, a
5、dministrations may exercise a degree of control over the number of systems that may generate interference at significant levels; 0 worse than that encountered by earth stations operating on land; that the interference level encountered by ship-borne earth stations in the MetSat service is unlikely t
6、o be 9) warranted between receiving and transmitting earth stations that operate in the same frequency band, Recommendation ITU-R IS.848, which provides the methodology for determining when coordination is recommends 1 that the single-entry interference levels presented in Table 1 be used as sharing
7、 criteria, or as the basis for alternative forms of sharing criteria (e.g., power flux-density limits), for the protection of stations operating in the EESS and MetSat service; 2 in the EESS and MetSat service in bands shared with terrestrial services; that the criteria specified in 0 1 be used as t
8、he basis for coordination thresholds for receiving stations operating 3 transmitting space stations and receiving earth stations operating in the EESS and MetSat service; that a 6% increase in equivalent link noise temperature be used as the threshold for coordination between 4 that the deployment o
9、f interferers specified in Annex 1 be reviewed periodically in order to determine whether the typical interference environment and consequential sharing criteria should be revised. NOTE 1 - The sharing criteria of Table 1 (including the Notes thereto) are intended to be applied in fiequency sharing
10、analyses and the coordination of fiequency assignments (Le., as the minimum levels of accepted interference for applicable earth stations). In coordination applications, the actual interference seen by the receiving earth station should be compared with that assumed in Annex 1 in order to help deter
11、mine whether an interfering signal power greater than the permissible single entry level can be accepted. Generally, this consideration may enable acceptance of interference levels that may be as high as those specified in the applicable interference criteria in Recommendation ITU-R SA.1160. = 48552
12、32 053bb02 b54 -170.7 dBW per 2.6 MHz() Rec. ITU-R SA.1161-1 73 -150.7 dBW per 2.6 MHd) NOTE 2 - The coordination threshold specified in 0 3 is sufficiently conservative to assure that interference will be below permissible levels in cases where coordination is not triggered. In order to apply that
13、criterion when determining whether interference from transmitting spacecraft might be unacceptable, the methodology of Appendix S8 to the Radio Regulations may be adapted and applied to the stations concerned. In order to avoid unnecessary coordination, administrations may wish to assume that a cert
14、ain amount of antenna discrimination is available from the receiving station (e.g., a level of discrimination that is available for 99.9% of the time). NOTE 3 - The criteria in Table 1 are based on the interference environment given in Annex 1 (also see 5 4). 670-1 710 down-link TABLE 1 Data dissemi
15、nation Low gain antenna Sharing criteria for stations in the EES and MetSat services using spacecraft in geostationary orbit -182.4 dBW per 4 kHz() Frequency band (MH4 -162.4 dBW per 4 kHz() Function and type of earth station 25 500-27 O00 Direct data readout High gain antenna I Direct data readout
16、-152 dBW -135 dBW 60.1 dBic antenna per 10 MHd2) per 10 MHd2) Interfering signal power (dBW) in the reference bandwidth to be exceeded for no more than 20% of the time Interfering signal power (dBW) in the reference bandwidth to be exceeded for no more thanp% ofthe time Terrestrial Space Terrestrial
17、 -165.3 dBW per 2. i 1 MH() -145.4 dBW per 2. i i MHZ() -159.4 dBW per 2.6 MHz() p = 0.0025 -1 52.7 dBW per 2.6 MHz() p = 0.011 -163.2 dBW per 4 kHz( ) p = 0.0025 -162.4 dBW per 4 kHz( ) p = 0.01 1 Data dissemination High gain antenna -153.4 dBW per 2.1 i MHZ() p = 0.0025 -1 16 dBW per 10 MH#) p = 0
18、.05 -147.2 dBW per 2.1 I MH() p = 0.01 1 -1 16 dBW per 10 MH#) p = 0.1 (I) The interfering signal powers (dBW) in the reference bandwidths are specified for reception at elevation angles 2 3“. (2) The interfering signal powers (dBW) in the reference bandwidths are specified for reception at elevatio
19、n angles I 5“. NOTE 1 -The single-entry interfering signal power thresholds in Table 1 is the permissible level of interfering signal power that falls within the specified reference bandwidth. Accordingly, the total power in interfering signals that are narrower than the reference bandwidth should b
20、e considered in frequency sharing analyses. In cases where the interfering bandwidth exceeds the reference bandwidth or does not fully overlap the passband of a specific receiver under study, the available frequency dependent rejection should be applied in conjunction with the specified permissible
21、interference levels. The pertinent ITU-R SM Series Recommendations should be consulted for guidance on this matter. NOTE 2 - The sharing criteria presented in Table 1 are based on representative stations having the specified antenna gain values. NOTE 3 - in deriving the above sharing criteria from p
22、ermissible total levels of interfering signal power, no allowance has been made for interference from spurious emissions. NOTE 4 -The specified level of single-entry interfering signai power may be directly converted to, and applied as, equivalent values of power nux-density only for earth stations
23、that use low-gain, non-tracking antenna. NOTE 5 - Both the long-term (20% of the time) and short-term % ofthe time) sharing criteria must be met in order for interference to be at or below permissible levels. NOTE 6 - Sharing criteria specified for terrestrial signal paths are applicable to transmit
24、ting stations in terrestrial services and transmitting earth stations. 74 Long-term apportionment between categories of interferers rl8552L2 053bbD3 590 Rec. ITU-R SA.1161-1 ANNEX 1 Basis of sharing criteria Short-term Equivalent apportionment number of between categories long-term of interferers in
25、terferers 1 Introduction This Annex presents the implementation of Recommendation ITU-R SA. 1023 using the interference criteria arrived at in Recommendation ITU-R SA. 1 160. The permissible interference levels are subdivided according to Recommen- dation ITU-R SA.1023 into space and terrestrial cat
26、egories and then into the number of anticipated interferers in each category. The basis for these allotments is shown in Table 2 and a discussion of the interference environment in each band is presented below. TABLE 2 Parameters used to derive sharing criteria Frequency band (MH4 1670-1 710 Functio
27、n and type of earth station Interfering Interfering interfering signal path signal path signal path Direct data 1% 99% 10% readout High gain antenna Data dissemination Low gain antenna 1 1% 1 99% I 10% I 90% I 1 I 1 Data dissemination High gain antenna I 1% 1 99% I 10% I 90% I 1 I 1 Equivalent numbe
28、r of short-term interferers interfering signal path Space- Terrestrial I Earth 112 I 2 The 1 670-1 690 MHz band is allocated on a primary basis to the MetSat (space-to-Earth), meteorological-aids, fixed and mobile (except aeronautical mobile) services. The 1 675-1 690 MHz band is allocated on a prim
29、ary basis to the mobile- satellite (Earth-to-space) service in Region 2. The 1690-1 700 MHz band is allocated on a primary basis to the meteorological-aids and MetSat (space-to-Earth) services and, in .Region 2, to the mobile-satellite service (Earth-to-space). The EESS is permitted provided such op
30、erations do not interfere with primary allocations. In ten countries a primary allocation exists for the fixed and mobile (except aeronautical mobile (R) services. In two countries the fixed and mobile (except aeronautical mobile (R) services have a secondary allocation. Considerations for the 1670-
31、1 710 MHz = 4855212 053bb04 427 Rec. ITU-R SA.1161-1 75 The 1700-1 710 MHz band is allocated on a primary basis to the fixed, mobile, and MetSat (space-to-Earth) services and, in Region 2, to the mobile-satellite (Earth-to-space) service. The EESS is permitted provided such operations do not interfe
32、re with primary allocations. In Region 3 space research (space-to-Earth) is allocated on a primary basis in four countries. Space-to-Earth systems in the 1670-1 675 MHz band may need to limit their emissions in order to protect the radioastronomy service operating in the adjacent band, such that ter
33、restrial stations produce most of the interference. Above 1675 MHz, it is expected that a greater number of space stations will operate and produce about the same long-term interference levels as terrestrial systems and relatively greater interference levels in the short term (Le., as a result of te
34、mporal variations in MetSat earth station antenna gain towards the interfering satellites). The expectation that mobile earth stations could contribute substantially to interference arriving via terrestrial paths does not warrant different interference allocations for interfering terrestrial paths in Region 2, since terrestrial stations and mobile earth stations are unlikely to use the same frequencies in the same area. Further information is provided in Recommen- dation ITU-R SA.1158.
