1、 Recommendation ITU-R F.1509-4 (01/2018) Technical and operational requirements that facilitate sharing between point-to-multipoint systems in the fixed service and the inter-satellite service in the band 25.25-27.5 GHz F Series Fixed service ii Rec. ITU-R F.1509-4 Foreword The role of the Radiocomm
2、unication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulato
3、ry and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/
4、ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-
5、R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound)
6、 BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination betwee
7、n fixed-satellite and fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic P
8、ublication Geneva, 2018 ITU 2018 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R F.1509-4 3 RECOMMENDATION ITU-R F.1509-4* Technical and operational requirements that facilitate sharing between point-to-multip
9、oint systems in the fixed service and the inter-satellite service in the band 25.25-27.5 GHz (Question ITU-R 118/7) (2001-2009-2013-2015-2018) Scope This Recommendation provides maximum e.i.r.p. density of transmitting hub and subscriber point-to-multipoint stations in the fixed service towards the
10、direction of the geostationary-satellite orbit to enable sharing with the inter-satellite service in the frequency band 25.25-27.5 GHz. The reference e.i.r.p. density in this Recommendation takes into account the need for transmission at the minimum necessary level while taking into account use of a
11、utomatic transmitter power control (ATPC) at the fixed service (FS) stations for precipitation events. Keywords Data relay satellites, orbital locations, e.i.r.p., spectral density Abbreviations ATPC Automatic transmitter power control DRS Data relay satellite e.i.r.p. Equivalent isotropically radia
12、ted power FS Fixed service GSO Geostationary-satellite orbit POCS Proximity operations communication system Related ITU Recommendations Recommendation ITU-R F.758 System parameters and considerations in the development of criteria for sharing or compatibility between digital fixed wireless systems i
13、n the fixed service and systems in other services and other sources of interference. Recommendation ITU-R F.1249 Technical and operational requirements that facilitate sharing between point-to-point systems in the fixed service and the inter-satellite service in the band 25.25-27.5 GHz. Recommendati
14、on ITU-R F.1336 Reference radiation patterns of omnidirectional, sectoral and other antennas for the fixed and mobile service for use in sharing studies in the frequency range from 400 MHz to about 70 GHz. Recommendation ITU-R SA.609 Protection criteria for radiocommunication links for manned and un
15、manned near-Earth research satellites. * This Recommendation was jointly developed by Radiocommunication Study Groups 7 and 5, and future revisions should be undertaken jointly. 4 Rec. ITU-R F.1509-4 Recommendation ITU-R SA.1018 Hypothetical reference system for systems comprising data relay satelli
16、tes in the geostationary orbit and user spacecraft in low Earth-orbits. Recommendation ITU-R SA.1155 Protection criteria related to the operation of data relay satellite systems. Recommendation ITU-R SA.1276 Orbital locations of data relay satellites to be protected from the emissions of fixed servi
17、ce systems operating in the band 25.25-27.5 GHz. The ITU Radiocommunication Assembly, considering a) that the band 25.25-27.5 GHz is allocated to the fixed, mobile and inter-satellite services on a primary basis; b) that in addition to point-to-point fixed service (FS) systems, point-to-multipoint (
18、P-MP) FS systems are planned to operate in the 25.25-27.5 GHz band; c) that space-to-space radiocommunication links in the inter-satellite service are used in the 25.25-27.5 GHz band; d) that space-to-space links are established between low-orbiting user satellites and geostationary data relay satel
19、lites (DRS) and also proximity operations communication system (POCS) between users in proximity of low-orbiting space stations; e) that these links, particularly the space-to-space links of a DRS network, are designed to operate with margins on the order of 2 dB to 4 dB; f) that satellite links are
20、 susceptible to interference from the emissions of fixed service systems within a field-of-view that is of large geographical extent; g) that specifying particular orbital locations to be protected rather than the orbital arc will impose less burden on the fixed service for band sharing, particularl
21、y for those stations located at high latitudes, recognizing a) that the protection criteria for POCS links may be found in Recommendation ITU-R SA.609, and the protection criteria for DRS links may be found in Recommendation ITU-R SA.1155; b) that a limited number of DRS networks, as described in Re
22、commendation ITU-R SA.1018, are either deployed or in the implementation phase in the geostationary orbit, at orbital locations given in Recommendation ITU-R SA.1276-5 (see Note 1); c) that Recommendation ITU-R F.758 provides a large variety of fixed wireless system parameters generalized by represe
23、ntative systems for specific frequency ranges, recommends 1 that for each transmitter of a hub station of a P-MP FS network operating in the 25.25-27.5 GHz band (see Annex 1 for the background of the e.i.r.p. limits): 1.1 the e.i.r.p. spectral density of the emission in the direction of any geostati
24、onary-satellite orbit (GSO) location specified in Recommendation ITU-R SA.1276 should not exceed the following values in any 1 MHz band for the elevation angle above the local horizontal plane (see Notes 1, 2 and 3): +8 dBW for 0 20 Rec. ITU-R F.1509-4 5 +14 10 log(/5) dBW for 20 148 dB(W/MHz) For o
25、rbits in which I 148 dB(W/MHz) Duration I 148 dB(W/MHz) (s) Percentage of orbit I 148 dB(W/MHz) Peak I (1) (dB(W/MHz) 174 W 145 6.1 to 30.9 12 5 to 50 0.1 to 0.8 143.8 41 W 145 7.7 to 71 11 10 to 60 0.2 to 1.0 137.8 85 E 145 N/A 0 N/A N/A 148.3 (1) The small differences in the peak levels found by t
26、he temporal and spatial analysis are due to: sampling effects between a spatial and temporal analysis, small model differences in hub antenna elevation pattern 3 dB beamwidth, upper elevation side-lobe contribution differences, operating frequency, and the inclusion of atmospheric bending effects (R
27、ecommendation ITU-R F.1333) in the spatial model. It is concluded that during the few orbits in which the interference level exceeds 148 dB(W/MHz), the protection level is exceeded by slightly more than 0.1% up to a worst case of about 1% of the time for a DRS located at 41 W and 174 W. For a DRS lo
28、cated at 85 E, the protection criteria of Recommendation ITU-R SA.1155 is satisfied. 4 Results of Study B The following sections present the results of the temporal and spatial analysis based on another study. In this study, an e.i.r.p. spectral density of +14 dB(W/MHz) per hub station will be assum
29、ed, in view of a need that certain systems may require an e.i.r.p. density larger than +8 dB(W/MHz). Two user satellites will be considered, international space station (orbital altitude of 400 km and inclination angle of 51.6) and EOS (orbital altitude of 800 km and inclination angle of 98.6). Shar
30、ing criterion of 142 dB(W/MHz) will be assumed instead of a protection criterion of 148 dB(W/MHz). 4.1 Results Temporal analysis For the purpose of this analysis, the worst-case interference scenario is presented, which is the 41 W DRS. Figure 10 illustrates the aggregate emissions from LMDS hubs re
31、ceived by the DRS as it tracks the international space station over a period of 30 days in 5 s increments. Figure 11 presents a similar graph for the DRS tracking the EOS. Rec. ITU-R F.1509-4 21 FIGURE 10 Interference into 41 W DRS while tracking the international space station F .15 09 -100 3012520
32、0148142T i m e s ( da ys )I(dB(W/MHz)FIGURE 11 Interference into 41 W DRS while tracking the EOS F .15 09 -110 30125200148142T i m e s ( da ys )I(dB(W/MHz)As shown in both Figures, the emissions from the LMDS deployments, operating at an e.i.r.p. of +14 dB(W/MHz) per hub station fall predominantly b
33、elow the sharing criterion of 142 dB(W/MHz). For the DRS tracking the international space station, the cumulative emissions exceeding the sharing criterion account for only approximately 0.1% of the time over the full 30 day period. This is illustrated in Fig. 12. As illustrated in Fig. 13, the cumu
34、lative emissions received by the DRS tracking 22 Rec. ITU-R F.1509-4 the EOS exceed the sharing criteria by approximately 0.06% of the time. It should be noted that these events originate from known predictable locations on Earth, which can be easily identified through simulation. FIGURE 12 Cumulati
35、ve interference into DRS 41 W while tracking the international space station over 30 days F .1509-12200 195 190 185 180 175 170 165 160 155 150 145 140 135 1301011031025210102152525252Ix ( dB ( W / M H z ) )%oftimewhenisIIxFIGURE 13 Cumulative interference into DRS 41 W while tracking EOS over 30 da
36、ys F .15 09 -13200 195 190 185 180 175 170 165 160 155 150 145 140 135 1301011031025210102152525252Ix ( dB ( W / M H z ) )%oftimewhenisIIxRec. ITU-R F.1509-4 23 The above results are consistent with the outcome of the spatial analysis discussed below. 4.2 Results Spatial analysis The results of the
37、spatial analysis are given for three DRS orbital positions including 41 W, 174 W, and 85 E. The 41 W and 174 W represent the worst-case scenario, and 85 E is a typical case where interference exists. It should be noted that for many orbital slots, the sharing criterion is not exceeded at all. Figure
38、 14 illustrates the spatial interference profile of LMDS emissions into the 41 W DRS. As shown, the emissions exceeding the 142 dB(W/MHz) sharing criterion are concentrated around specific predictable locations. Figures 15 and 16 depict similar graphs for the 174 W and 85 E orbital positions. FIGURE
39、 14 Spatial interference profile for 41 W DRS F .1509-14dB ( W / M H z )0.001.002.003.004.005.006.007.008.009.0010.0011.0012.0013.001.002.003.004.005.006.007.008.009.0010.0011.0012.0013.000.001.002.003.004.005.006.007.008.009.0010.001 1.0 01.002.003.004.005.006.007.008.009.0010.001 1.0 0P i t c h (
40、de gr e e s )Roll(degrees)136.00 t o 130.00142.00 t o 136.00148.00 t o 142.00G e os t a t i ona r y D R S 41 W , = 0, r e s . = 0.2 , 8 dB ( W / M H z ) , 43 1 L M D S s e r vi c e a r e a s , 94 4 h ubs w or l dw i dek24 Rec. ITU-R F.1509-4 FIGURE 15 Spatial interference profile for 174 W DRS F .15
41、09-15dB ( W / M H z )0.001.002.003.004.005.006.007.008.009.0010.0011.0012.0013.001.002.003.004.005.006.007.008.009.0010.0011.0012.0013.00P i t c h ( de gr e e s )136.00 t o 130.00142.00 t o 136.00148.00 t o 142.00G e os t a t i ona r y D R S 174 W , = 0, r e s . = 0.2, 8 dB ( W / M H z ) , 431 L M D
42、 S s e r vi c e a r e a s , 944 hubs w or l dw i dek0.001.002.003.004.005.006.007.008.009.0010.001 1.001.002.003.004.005.006.007.008.009.0010.001 1.00Roll(degrees)Rec. ITU-R F.1509-4 25 FIGURE 16 Spatial interference profile for 85 E DRS F . 1509- 16dB(W / M H z )0.001.002.003.004.005.006.007.008.00
43、9.0010.0011.0012.0013.001.002.003.004.005.006.007.008.009.0010.0011.0012.0013.00P i t c h (d e gre e s )136.00 t o 130.00142.00 t o 136.00148.00 t o 142.00G e os t a t i ona ry D RS 85 E , = 0, re s . = 0.2 , 8 dB(W / M H z ), 4 31 L M D S s e rvi c e a re a s , 94 4 h ubs w orl dw i dek0.001.002.00
44、3.004.005.006.007.008.009.0010.0011.001.002.003.004.005.006.007.008.009.0010.0011.00Roll(degrees)It should be noted that the above graphs are based on simulation runs using k = 0 for the antenna radiation patterns in Recommendation ITU-R F.1336. Simulation runs were also performed using k = 1 (highe
45、r side-lobes), and it was observed the overall interference profile remained relatively constant, suggesting the sidelobe contributions are negligible. 4.3 Discussion of results ( 4) As indicated from the above analysis, a sharing criterion of 142 dB(W/MHz) allows sharing between the two services wi
46、thout overly constraining either service. Sharing criteria, unlike protection criteria, must recognize the specific nature of the services in the band and reflect the need to accommodate those services. In the case of DRS sharing the 25.25-27.5 GHz band with P-MP FS systems there are a number of mit
47、igating factors which would support a sharing criterion of 142 dB(W/MHz), for example: 26 Rec. ITU-R F.1509-4 As discussed, the use of sectorized antenna systems with downtilt will be common place in P-MP deployments. Systems will require a significant level of sectorization to control intra-systems
48、 interference and to achieve frequency reuse levels that support business cases. The emissions that do exceed the sharing criterion originate from predictable locations on Earth, allowing a priori measures to be taken to avoid interference. The use of the band 25.25-27.5 GHz by the fixed service var
49、ies from administration to administration. In some countries, operators are authorized for point-to multipoint systems, in other countries, operators use a mix of point-to-point and P-MP systems (some broadband operators use multiple point-to-point systems from a central site). In addition, current band plans support a range of point-to-point and P-MP systems. Consequently, the aggregate
