1、 Recommendation ITU-R F.1247-4 (09/2015) Technical and operational characteristics of systems in the fixed service to facilitate sharing with the space research, space operation and Earth exploration-satellite services operating in the bands 2 025-2 110 MHz and 2 200-2 290 MHz F Series Fixed service
2、 ii Rec. ITU-R F.1247-4 Foreword The role of the Radiocommunication 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 th
3、e basis of which Recommendations are adopted. The regulatory 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
4、on IPR is described in the Common Patent Policy for ITU-T/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
5、 Implementation of the Common Patent Policy for ITU-T/ITU-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 pla
6、y-out; film for television BS Broadcasting service (sound) 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 an
7、d meteorology SF Frequency sharing and coordination between 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
8、the procedure detailed in Resolution ITU-R 1. Electronic Publication 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.1247-4 1 RECOMMENDATION ITU-R F.1247-4* Technical and operational ch
9、aracteristics of systems in the fixed service to facilitate sharing with the space research, space operation and Earth exploration-satellite services operating in the bands 2 025-2 110 MHz and 2 200-2 290 MHz (Question ITU-R 118/7) (1997-2000-2009-2013-2015) Scope This Recommendation provides operat
10、ional characteristics of fixed service systems to facilitate sharing with systems in the space science services that operate in the bands 2 025-2 110 MHz and 2 200-2 290 MHz. It provides, inter alia, the orbital locations of the GSO satellites toward which emissions should be limited. Keywords Data
11、relay satellites, orbital locations, e.i.r.p., spectral density The ITU Radiocommunication Assembly, considering a) that the bands 2 025-2 110 MHz and 2 200-2 290 MHz are allocated in the Radio Regulations (RR) to the fixed, mobile, space research (SR), space operation (SO) and Earth exploration-sat
12、ellite (EES) services on a primary basis; b) that a variety of point-to-point and point-to-multipoint fixed service (FS) systems operate in the 1-3 GHz range and are described in Recommendations ITU-R F.758 and ITU-R M.1143; c) that, as a result of the World Administrative Radio Conference for Deali
13、ng with Frequency Allocations in Certain Parts of the Spectrum (Malaga-Torremolinos, 1992) (WARC-92), other services were allocated in the 1-3 GHz range which has created incompatible sharing conditions with the fixed service; d) that the SR, SO and EES services have operated satisfactorily for many
14、 years with the fixed service in the bands 2 025-2 110 MHz and 2 200-2 290 MHz but, should large numbers of fixed service systems be introduced, it will be important to identify preferred fixed service technical and operational characteristics to ensure long-term compatibility; e) that the SR, SO an
15、d EES services operate space-to-space radiocommunication links in the bands 2 025-2 110 MHz and 2 200-2 290 MHz, in addition to Earth-to-space and space-to-Earth links, respectively; f) that these links, particularly the space-to-space links of a data relay satellite (DRS) network, are designed to o
16、perate with margins on the order of 2 dB to 4 dB; g) that the protection criteria for Earth-to-space and space-to-Earth links may be found in Recommendations ITU-R SA.363 and ITU-R SA.609, and the protection criteria for DRS links may be found in Recommendations ITU-R SA.1155 and ITU-R SA.1274; * Th
17、is Recommendation was jointly developed by Radiocommunication Study Groups 7 and 5, and future revision should be undertaken jointly. 2 Rec. ITU-R F.1247-4 h) that the number of fixed service systems in these bands may increase to an extent that practical sharing criteria that are less stringent tha
18、n Recommendation ITU-R SA.1155 may need to be used as given in Recommendation ITU-R SA.1274; j) 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; k) that a limited number of DRS networks, as d
19、escribed in Recommendation ITU-R SA.1018, are either operating or planned for deployment in the geostationary orbit, as listed in Recommendation ITU-R SA.1275; l) that specifying particular orbit locations to be protected rather than the orbital arc will impose less burden on the fixed service for b
20、and sharing, particularly for those stations located at high latitudes; m) that studies summarized in Annex 1 have shown that technical means may be utilized by the fixed service to reduce the potential for unacceptable interference to the space research, space operation and EES services, recommends
21、 1 that fixed service stations in the bands 2 025-2 110 MHz and 2 200-2 290 MHz, where practicable use: 1.1 automatic transmit-power control (ATPC) such that the mean power is a minimum 10 dB below the maximum transmitter power; 1.2 the lowest practical transmitter power spectral density; 1.3 transm
22、itting antennas with good radiation patterns taking into account Recommendation ITU-R F.699; 2 that, as far as practicable, point-to-point fixed service stations operating in the band 2 200-2 290 MHz avoid radiating at an e.i.r.p. spectral density greater than +8 dB(W/MHz) towards geostationary DRS
23、locations specified in Recommendation ITU-R SA.1275 (see Notes 2 and 6); 2.1 that, as an exception to recommends 2, the e.i.r.p. spectral density of fixed service stations which employ ATPC may be increased above +8 dB(W/MHz) in the direction of the specified geostationary DRS location for less than
24、 0.1% of the month (see Notes 7 and 8); 2.2 that fixed service stations which are unable to comply with recommends 2 should operate towards the lower part of the band 2 200-2 290 MHz (see Note 8); 3 that point-to-multipoint fixed service stations in the bands 2 025-2 110 MHz and 2 200-2 290 MHz, whe
25、re practicable: 3.1 avoid radiating an e.i.r.p. density per link exceeding 5 dB(W/MHz) for both central and out-stations of high power/low density systems for more than 0.1% of the month taking into account ATPC (see Notes 1, 2, 3, 4, 5 and 7); 3.2 use at the central station omnidirectional transmit
26、ting antennas with minimal gain above the horizontal plane. NOTE 1 recommends 2 applies also to point-to-point links between or within point-to-multipoint systems. NOTE 2 The e.i.r.p. spectral density radiated towards a geostationary DRS should be calculated as the product of the transmitted power s
27、pectral density and the gain of the antenna in the direction of the DRS. In the absence of a radiation pattern for the fixed service antenna, the reference radiation pattern of Recommendation ITU-R F.699 should be used. The calculation should take into Rec. ITU-R F.1247-4 3 account the effects of at
28、mospheric refraction and the local horizon. A method for calculating separation angles is given in Annex 2 of Recommendation ITU-R F.1249. NOTE 3 recommends 2 also applies to out-stations of point-to-multipoint (P-MP) systems employing directional antennas with a maximum gain in excess of 14 dBi. NO
29、TE 4 In a high power/low density P-MP system operating in intermittent transmission modes such as TDMA, the out-stations may increase their e.i.r.p. density levels by a factor corresponding to the number of subscribers connected to the out-stations belonging to a central station up to a maximum of 9
30、 dB(W/MHz) (see 3.7 of Annex 1). NOTE 5 recommends 3.1 applies primarily to lower density systems. For higher density systems, the appropriate power levels are lower. For example, parameters for a low power system used by at least one administration operates at typical non-faded e.i.r.p. densities p
31、er link in the order of 5 dB(W/MHz) for central stations and 14 dB(W/MHz) for out-stations, taking into account ATPC, where practicable. NOTE 6 Recommendation ITU-R SA.1275-4 identifies the following geostationary DRS orbital positions: 10.6 E, 16.4 E, 16.8 E, 21.5 E, 47 E, 59 E, 77 E, 80 E, 85 E, 8
32、9 E, 90.75 E, 95 E, 113 E, 121 E, 133 E, 160 E, 167 E, 171 E, 176.8 E and 177.5 E, 12 W, 16 W, 32 W, 41 W, 44 W, 46 W, 49 W, 62 W, 79 W, 139 W, 160 W, 164.2 W, 167.5 W, 170 W, 171 W and 174 W. When Recommendation ITU-R SA.1275 is revised so that new DRS orbital locations are added, the protection of
33、 the space stations in these new orbital slots in revision to this Recommendation applies only to FS stations installed after the enforcement date of the revised Recommendation ITU-R SA.1275. NOTE 7 It should be noted that the time percentages in recommends 2.1 and 3.1 do not directly relate to the
34、DRS time percentage sharing criteria as given in Recommendation ITU-R SA.1274. NOTE 8 A fixed service station employing ATPC, which is unable to comply with the requirement in recommends 2.1, should, where practicable, operate towards the lower part of the band 2 200-2 290 MHz, preferably 2 200-2 24
35、5 MHz and the e.i.r.p. spectral density (in the direction of the specified geostationary DRS location) of such station may be increased above +8 dB(W/MHz) for less than 5% of the month in order to restore performance during shallow fading events, but the time percentage exceeding +11 dB(W/MHz) shoul
36、d be less than 0.1%. NOTE 9 Annex 2 presents material to facilitate the application of this Recommendation to planning and design of new systems in the bands 2 025-2 110 MHz and 2 200-2 290 MHz. 4 Rec. ITU-R F.1247-4 Annex 1 Technical characteristics of fixed service systems to facilitate sharing wi
37、th the space services in the bands 2 025-2 110 MHz and 2 200-2 290 MHz 1 Introduction Studies have shown that interference may be caused by the emissions of fixed service systems to space networks operating in the SR, SO and EES services (the space science services) in the bands 2 025-2 110 MHz and
38、2 200-2 290 MHz (the 2 GHz bands). The space network consists of space-to-space links between a DRS in geostationary-satellite orbit (GSO) and a low-orbiting satellite. The DRS transmits to a low-orbiting satellite in the band 2 025-2 110 MHz and receives transmissions from the low-orbiting satellit
39、e in the band 2 200-2 290 MHz. Thus, the low-orbiting satellite is susceptible to interference from emissions in the band 2 025-2 110 MHz and GSO DRSs are susceptible to interference from the emissions in the band 2 200-2 290 MHz. Low-orbiting satellites may also communicate with ground stations in
40、the ground network using Earth-space links. These links, which use the band 2 025-2 110 MHz to transmit to a low-orbiting satellite and the band 2 200-2 290 MHz to receive from a low-orbiting satellite, are not as susceptible to interference as the links for low-orbiting satellites operating in the
41、space network. Section 2 summarizes the interference environment as might be seen by low-orbiting satellites and GSO DRSs if there is intense use of the 2 GHz bands by the fixed service. Section 3 summarizes the interference mitigation techniques that could be employed by the fixed service to reduce
42、 levels of potential interference. Section 4 presents a summary of the effectiveness of the various mitigation techniques to reduce the level of potential interference to satellites operating in the space network. 2 Potential interference to satellites operating in the space network Monte Carlo simu
43、lations have been used to evaluate the interference to space science services systems from a potentially large number of fixed service systems. It was assumed that the fixed service systems were line-of-sight point-to-point systems consisting of 13 stations per section; that used digital modulation
44、techniques and employed high-gain antennas. The deployment of the fixed service systems was assumed to correspond to the locations of some 1 245 major cities of the world. Excluded from the list were cities of the United States of America since the bands are extensively used for other applications.
45、These assumptions result in more than 16 000 point-to-point stations being deployed throughout the world. There are 13 stations per route. The routes are assumed to be centred at each of the major cities. A trendline is established that is uniformly distributed between 0 and 360. From this point the
46、 geographic position vector and the antenna pointing vector at each station on the route is generated assuming the stations are separated by 50 km. The azimuth angle at each station is the sum of the trendline angle and a random angle uniformly distributed between 12.5. At every other station that i
47、s not an end station, it is assumed that there are two co-channel transmitting antennas: one pointing at the preceding station along the route and the other pointing at the next station along the route. The antennas at the end stations point toward the adjacent station. Each antenna has an elevation
48、 angle of 0, exhibits an on-axis gain of 33 dBi, and an off-axis radiation pattern that conforms to the improved pattern given in Recommendation ITU-R F.699. The transmitter power spectral density at each transmitting station is assumed to be 35 dB(W/kHz) which is consistent with 64-QAM digital syst
49、ems. Rec. ITU-R F.1247-4 5 The effect of the global deployment of these 13 station sections of radio-relay routes on low-orbiting satellites operating in the band 2 025-2 110 MHz is determined by calculating the aggregate interference power received by these satellites as a function of the latitude and longitude of the sub-satellite point of the satellite position vector. It is assumed that the interference to the low-orbiting satellite is coupled into the receiving system through antenna side lobes which exhibit 0 dBi gain. A
