1、 Rec. ITU-R BO.1834 1 RECOMMENDATION ITU-R BO.1834* Coordination between geostationary-satellite orbit fixed-satellite service networks and broadcasting-satellite service networks in the band 17.3-17.8 GHz and among the broadcasting-satellite service and associated feeder-link networks serving Regio
2、n 2 in the bands 17.3-17.8 GHz and 24.75-25.25 GHz (2007) Scope This Recommendation addresses the issue of inter-service coordination between BSS networks serving Region 2 and FSS networks serving Regions 1 and/or 3 in all or part of the frequency band 17.3-17.8 GHz. This issue arises as a consequen
3、ce of the introduction of the primary BSS allocation in Region 2 as of 1 April 2007, and the existing primary space-to-Earth FSS allocation in Region 1 (17.3-17.8 GHz) and Region 3 (17.7-17.8 GHz). It also addresses the issue of intra-service coordination among BSS and associated feeder-link network
4、s in all or part of the frequency bands 17.3-17.8 GHz and 24.75-25.25 GHz. Representative FSS and BSS network characteristics are considered in order to perform a technical analysis of the coordination requirements. The ITU Radiocommunication Assembly, considering a) that, per No. 5.517 of the Radio
5、 Regulations (RR), as of 1 April 2007, the broadcasting-satellite service (BSS) allocation in Region 2 in the band 17.3-17.8 GHz is in effect; b) that there is a requirement for identifying the need for coordination between fixed-satellite service (FSS) networks serving Regions 1 and/or 3, and BSS n
6、etworks serving Region 2; c) that simple methods for identifying the need to coordinate between FSS and BSS networks and among BSS and associated feeder-link networks would accelerate the coordination process; d) that typical network characteristics of BSS and FSS networks can be assumed for the est
7、ablishment of a coordination arc to be applied between such networks; e) that, when a coordination arc applies for the determination of coordination requirements, administrations can request, under the provisions of No. 9.41 of the RR, to be included in the coordination process for networks outside
8、the established coordination arc defined in Appendix 5 of the RR; f) that, in the cases referred to in considering e), administrations requesting to be included in the coordination process may need some information in order to help them in conducting this coordination, * The Syrian Arab Republic is
9、of the view that this Recommendation does not provide additional information with regard to the decisions adopted by WRC-2000 and WRC-03. 2 Rec. ITU-R BO.1834 recognizing a) that, per No. 5.517 of the RR, the fixed-satellite service (space-to-Earth) in Region 2 in the band 17.7-17.8 GHz shall not cl
10、aim protection from and shall not cause harmful interference to the broadcasting-satellite service in this band, recommends 1 that administrations, when conducting coordination under the provisions of No. 9.7 of the RR, between assignments pertaining to GSO BSS and associated feeder-link networks se
11、rving Region 2 in the frequency bands 17.3-17.8 GHz and 24.75-25.25 GHz, should take into consideration the material provided in Annex 1 in order to facilitate this coordination; 2 that administrations, when conducting coordination under the provisions of No. 9.7 of the RR, between assignments perta
12、ining to a GSO FSS network serving Region 2 in the frequency band 17.3-17.8 GHz and assignments pertaining to a GSO BSS network serving Region 1 and/or 3 in the same frequency band, should take into consideration the material provided in Annex 2 in order to facilitate this coordination. Annex 1 Coor
13、dination among GSO BSS and associated feeder-link networks serving Region 2 in the 17.3-17.8 GHz and 24.75-25.25 GHz unplanned frequency bands 1.1 Introduction WRC-03 adopted a provisional value of 16 as the coordination arc applicable for the BSS in bands above 17.3 GHz. Resolution 901 (WRC-03) inv
14、ites ITU-R to “conduct studies on the applicability of the coordination arc concept for space radiocommunication services not yet covered by these Regulations”. This Annex provides the results of a study to determine the applicability of the provisional coordination arc value for triggering coordina
15、tion for the 25/17 GHz BSS frequency band in Region 2. Based on information supplied by Canada in accordance with Appendix 4 of the RR, the analysis was performed for two Canadian BSS networks using the unplanned bands 24.75-25.25 GHz (feeder link) and 17.3-17.8 GHz (downlink). Both the traditional
16、BSS system and multimedia forward link were examined. The coordination filings for the CAN-BSS network are divided into two different groups embracing two system designs, and eleven orbital positions. The first group, called CAN-BSS-A for the purpose of this study, covers five orbital positions rang
17、ing from 78 W to 103 W. The second group, CAN-BSS-B, covers the remaining six orbital positions from 82 W to 118.7 W. Appendix 8 of the RR contains a method for calculating the need for coordination between two geostationary satellites sharing the same frequency band. It is based on the increase of
18、the equivalent satellite noise temperature due to interference. Given that coordination is required for any T/T greater or equal to 6%, this method can be reengineered to find the required orbital spacing between satellites. Rec. ITU-R BO.1834 3 1.2 Assumptions and results 1.2.1 Assumptions In order
19、 to perform the analysis, a certain number of assumptions were made. 1. A homogeneous satellite model was used for the interfering satellite, based on the design of the wanted satellite for each group. 2. Since the coordination filings are identical for each of the two groups, a single central satel
20、lite longitude was chosen to represent each group. 3. The wanted and interfering earth stations were assumed to be in the same location as this represents the worst-case scenario. In both the traditional broadcast and multimedia cases, the downlink beams are designed to uniformly cover the entire se
21、rvice area (in this case North and/or South America depending on the network). The traditional broadcast configuration uses one regional beam to illuminate the service area whereas the multimedia configuration uses many smaller steerable spot beams to illuminate the service area. 4. As Recommendatio
22、n ITU-R S.465 does not define the main lobe, the antenna pattern in Annex 3 of Appendix 8 of the RR was used to define the antenna gain for those off-axis angles outside the range of Recommendation ITU-R S.465-5. This is consistent with the software implementation of earth station antenna patterns f
23、or use in coordination, as developed by BR. 5. The signal polarity was assumed to be the same between beams. 1.2.2 Results of analysis for traditional BSS configurations Table 1 illustrates both the maximum and average (mean) values for the orbital separation required for coordination under the T/T
24、method, for both the North American and South American beams. The CAN-BSS-A group uses a 25 MHz transponder bandwidth, while CAN-BSS-B group uses a 27 MHz bandwidth. The coordination arc is defined as the nominal orbital position of the satellite plus and minus the required orbital separation based
25、on the T/T method. TABLE 1 Required orbital separation for Canadian networks using a traditional broadcast configuration Broadcasting-satellite service North American beams: CAN-BSS-A CAN-BSS-B MAX MEAN MAX MEAN 9.08 6.94 6.13 5.72 Broadcasting-satellite service South American beams: CAN-BSS-A CAN-B
26、SS-BMAX MEAN MAX MEAN 8.88 7.11 6.03 5.44 4 Rec. ITU-R BO.1834 1.2.3 Results of analysis for multimedia broadcast configuration (forward-link only) Table 2 illustrates both the maximum and average (mean) values for the orbital separation required for coordination under the T/T method. Unlike the tra
27、ditional broadcast configurations above, which have different beams for North and South America, the service area for the multimedia configuration covers the visible Earth. TABLE 2 Required orbital separation for Canadian networks using a multimedia broadcast configuration Multimedia-satellite servi
28、ce Forward link: CAN-BSS-A CAN-BSS-B MAX MEAN MAX MEAN 17.95 16.11 16.47 15.74 Comparing Tables 1 and 2, it is observed that the coordination arc values of multimedia broadcast configuration are significantly larger than that of the traditional broadcast configuration. The major difference between t
29、he traditional broadcast and multimedia configurations are that while the traditional mode uses one regional shaped beam, the multimedia mode uses several smaller spot beams. Due in part to the higher gain of the spot beams, the e.i.r.p. for the multimedia configuration is higher compared to the tra
30、ditional broadcast configuration. There is also an increase in the intersystem interference as multiple beams are required to cover the intended service area. Frequency reuse plans as well as channel and traffic planning can and are used to help mitigate this interference. The methodology of Appendi
31、x 8 of the RR assumes that both the wanted and interfering earth stations operate at the exact same frequency. This represents the absolute worst-case scenario does not take into account any mitigation techniques. This accounts for the increase in orbital separation required to reach a T/T equal to
32、6%. 1.3 Conclusion The coordination arc values calculated for the CAN-BSS networks using the traditional BSS design, which uses one shaped beam to cover the entire service area, range from 5 to 9. This is well within the proposed value of 16. Without taking into account any interference mitigation t
33、echniques, the multimedia broadcast design, utilizing spot beams and higher gain antennas, requires larger coordination arc values, which range from 16 to 18. This is slightly above the proposed coordination arc value contained in Appendix 5 of the RR. Consequently, the results presented in this Ann
34、ex show that a coordination arc of 16 degrees is appropriate for intraservice, intraregional coordination for Region 2 BSS and associated feeder-link systems in the bands 17.3-17.8 GHz and 24.75-25.25 GHz. Rec. ITU-R BO.1834 5 Annex 2 Coordination between GSO FSS (space-to-Earth) networks and Region
35、 2 GSO BSS networks in the band 17.3-17.8 GHz 2.1 Introduction Following the decision of WRC-03 to introduce a preliminary value of 16 for the coordination arc associated with BSS networks in frequency bands above 17.3 GHz, ITU-R reviewed the appropriateness of such a value for the specific case of
36、the interregional coordination between FSS (space-to-Earth) with respect to BSS in Region 2 in the frequency band 17.3-17.8 GHz. This band is allocated, inter alia, to the broadcasting-satellite service in Region 2 and to the fixed-satellite service in the space-to-Earth direction in Region 1. No. 5
37、.516B of the RR applies with regard to the FSS downlink allocation in the frequency band 17.3-17.7 GHz. No. 5.517 of the Radio Regulations applies with regard to the FSS downlink allocation in Region 2 in the frequency band 17.7-17.8 GHz. This Annex records the studies performed within ITU-R on the
38、specific case described above and provides the results derived from these studies. This Annex only addresses the interservice coordination between BSS in Region 2 and FSS (space-to-Earth) in Region 1. The results given in this Annex essentially rely on the fact that there exists a natural geographic
39、al isolation between land masses of the two Regions. Therefore they can not be extended to the intraservice BSS coordination in Region 2. They can, however, easily be extended to FSS (space-to-Earth) in Region 3 with respect to BSS in Region 2, since there exists a similar geographical isolation bet
40、ween these two Regions. 2.2 Methodology The methodology to study the appropriate possible coordination arc value was derived from the method described in Appendix 8 of the Radio Regulations as prescribed by Appendix 5 of the RR for requests for coordination under No. 9.7 of the RR. The purpose of th
41、is analysis is: 1. To assess the e.i.r.p. which could be radiated over Region 2 by an FSS network without triggering a coordination with a BSS network depending of the orbital separation between the two networks. 2. To compare the values found in the studies described above with technical parameters
42、 of BSS and FSS systems intended to be deployed in the band 17.3-17.8 GHz. 2.2.1 Derivation of maximum e.i.r.p. radiated without triggering a coordination From the receiving system noise temperature and the interference criterion, an interference density was computed. The e.i.r.p. density towards a
43、Region was then computed from this interference density taking into account only free space loss: ()=tESdESgklttTdensityprie log10).(. 6 Rec. ITU-R BO.1834 where: e.i.r.p. (density): e.i.r.p. density radiated by a satellite towards a Region (dBW/Hz) TES: receiving earth station system noise temperat
44、ure at antenna output (K) t/t: interference criterion k: Boltzmanns constant ()KJ231038.1 ld: downlink free space loss gES(t): receiving earth station antenna gain towards the interfering satellite t: topocentric angle between wanted and interfering satellites. The free-space loss was computed assum
45、ing a distance of 38 650 km and a frequency of 17.3 GHz. It was further assumed that the topocentric angle is 10% larger than the geocentric angle. No polarization advantage was taken into account. 2.3 Technical parameters of BSS and FSS systems 2.3.1 BSS systems 2.3.1.1 Interference criterion The c
46、riterion is derived from the section of Appendix 5 of the RR dealing with No. 9.7 of the RR under which BSS networks in the band 17.3-17.8 GHz in Region 2 are coordinated: %6=TT2.3.1.2 Receiving earth station characteristics The following characteristics of BSS systems intended to be deployed in the
47、 band 17.3-17.8 GHz are extracted from Appendix 1 to this Annex: antenna diameter: 30 cm1, 45 cm, 60 cm, 90 cm, 120 cm and 140 cm2; antenna radiation pattern: five antenna patterns were considered, namely Annex III of Appendix 8 of the RR, Recommendation ITU-R S.465-5 (complemented by Appendix 8 of
48、the RR for the main beam), Recommendation ITU-R S.580-6 (complemented by Appendix 8 of the RR for the main beam), Recommendation ITU-R BO.1213-1 and the pattern given in Appendix 1 to this Annex; receiving system noise temperature at the output of BSS earth station antenna: two values for the earth
49、station noise temperature were considered, namely 140 K and 170 K. For the purpose of this Annex, the more sensitive value was used, i.e. 140 K. 1Appendix 1 to this Annex does not mention the possible use of 30 cm antennas. It is however felt that this may occur in the future. Therefore, this analysis was conducted by including such an antenna diameter. The results are presented as two separate cases (Tables 4 and 5) depending on the inclusion of the 30 cm antennas or not. 2Community reception may use larger antennas. However
