1、 Recommendation ITU-R F.1509-3 (09/2015) 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.1509-3 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, 2015 ITU 2015 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R F.1509-3 1 RECOMMENDATION ITU-R F.1509-3* 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) 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 direc
10、tion of the geostationary-satellite orbit to enable sharing with the inter-satellite service in the 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 automatic transm
11、itter power control (ATPC) at the fixed service (FS) stations for precipitation events. Keywords Data relay satellites, orbital locations, e.i.r.p., spectral density The ITU Radiocommunication Assembly, considering a) that the band 25.25-27.5 GHz is allocated to the fixed, mobile and inter-satellite
12、 services on a primary basis; b) that in addition to point-to-point fixed service (FS) systems, point-to-multipoint (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;
13、 d) that space-to-space links are established between low-orbiting user satellites and geostationary data relay satellites (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 l
14、inks of a DRS network, are designed to operate with margins on the order of 2 dB to 4 dB; f) that satellite links are 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 t
15、o be protected rather than the orbital arc will impose less burden on the fixed service for band sharing, particularly for those stations located at high latitudes, * This Recommendation was jointly developed by Radiocommunication Study Groups 7 and 5, and future revisions should be undertaken joint
16、ly. 2 Rec. ITU-R F.1509-3 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 Recommendation ITU-R SA.
17、1018, are either deployed or in the implementation phase in the geostationary orbit, at orbital locations given in Recommendation ITU-R SA.1276-4 (see Note 1); c) that Recommendation ITU-R F.758 provides a large variety of fixed wireless system parameters generalized by representative systems for sp
18、ecific 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 geostationary-satellite orbit
19、(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 +14 10 log(/5) dBW for 20 148 dB(W/MHz) For orbits in which I 148 dB(W/MHz) Duration I 14
20、8 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 the temporal and spatial analysis are due to:
21、 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 (Recommendation ITU-R F.1333) in the spatial m
22、odel. 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 located at 85 E, the protection criteria of Re
23、commendation 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 assumed, in view of a need that certain systems m
24、ay 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). Sharing criterion of 142 dB(W/MHz) will be assum
25、ed 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 received by the DRS as it tracks the internati
26、onal space station over a period of 30 days in 5 s increments. Figure 11 presents a similar graph for the DRS tracking the EOS. 18 Rec. ITU-R F.1509-3 FIGURE 10 Interference into 41 W DRS while tracking the international space station F .15 09 -100 30125200148142T i m e s ( da ys )I(dB(W/MHz)FIGURE
27、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 below the sharing criterion of 142 dB(W/MHz).
28、 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 cumulative emissions Rec. ITU-R F.1509-3 19 rece
29、ived by the DRS tracking 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 Cumulative interference into DRS 41 W while tracking
30、 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 ) )%oftimewhenisIIx20 Rec. ITU-R F.1509-3 FIGURE 13 Cumulative interference into DRS 41 W while tracking EOS over 30 days F .15 09 -13200 19
31、5 190 185 180 175 170 165 160 155 150 145 140 135 1301011031025210102152525252Ix ( dB ( W / M H z ) )%oftimewhenisIIxThe above results are consistent with the outcome of the spatial analysis discussed below. 4.2 Results Spatial analysis The results of the spatial analysis are given for three DRS orb
32、ital 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 14 illustrates the spatial interference pro
33、file 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. Rec. ITU-R F.1509-3 21 FIGURE 14 Spatial interfere
34、nce 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 ( de gr e e s )Roll(deg
35、rees)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 dek22 Rec. ITU-R F.1509-3 FIGURE 15 Spatial interference profile for 174 W DRS F .1509-15dB ( W / M H z )
36、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 S s e r vi c e a r e
37、 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.1509-3 23 FIGURE 16 Spatial interference profile for 85 E DRS F . 1509- 16dB(W / M H z )0.001.002.003.004.005.006.007.008.009.0010.0011.0012.0013
38、.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 dek0.001.002.003.004.005.006.007.008
39、.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 (higher side-lobes), and it
40、 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 without overly constrai
41、ning 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 mitigating factors which
42、 would support a sharing criterion of 142 dB(W/MHz), for example: 24 Rec. ITU-R F.1509-3 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 interference and to
43、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 varies from administrati
44、on 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
45、range of point-to-point and P-MP systems. Consequently, the aggregate emission level from multipoint systems into DRS systems is likely to be much less than characterized in this study. 5 Extension to other LMDS deployments The results described in 3 and 4 are based on specific assumptions regarding
46、 the radius of the LMDS cell. This section describes a simple means to extend the results to LMDS deployments that use smaller cells. In general, smaller cell sizes will lead to a larger number of cells in a mature deployment of LMDS systems in urban population centres. As a consequence of the small
47、er cell size, the hub station e.i.r.p. required to provide the same link margin to the outermost subscriber will decrease as the square of the distance, assuming line-of-sight propagation. Thus, the relative reduction in the e.i.r.p. spectral density for cells smaller than the reference cell is give
48、n by: 0log20 rrii (10) where: i : e.i.r.p. spectral density reduction factor for the i-th cell (dB) ri : radius of the i-th cell (km) r0 : radius of the reference cell, i.e. 5 km. The application of the reduction factor is straightforward. For example, assume that the e.i.r.p. spectral density of th
49、e 5 km reference cell is +8 dB(W/MHz); were the cell size reduced to 2.5 km, the e.i.r.p. spectral density would be reduced to +2 dB(W/MHz). It is noted that the application of this approach will tend to limit the aggregate e.i.r.p. spectral density from any urban population centre to a level that is independent of the cell size. Note that the deployment objective for many f
