1、 Rep. ITU-R SM.2091 1 REPORT ITU-R SM.2091*,*Studies related to the impact of active space services allocated in adjacent or nearby bands on radio astronomy service (2007) TABLE OF CONTENTS Page 1 Introduction 5 2 Methodology. 5 2.1 General 5 2.2 Detailed description of the flow chart (see Fig. 1) .
2、 8 3 Compatibility analysis between RAS systems operating in the 150.05-153.0 MHz band and mobile-satellite service (space-to-Earth) systems operating in the 137-138 MHz band. 17 3.1 RAS. 17 3.2 MSS 18 3.3 Compatibility threshold 19 3.4 Interference assessment 19 3.5 Mitigation techniques . 25 4 Com
3、patibility analysis between RAS systems operating in the 322-328.6 MHz band and mobile-satellite service (space-to-Earth) systems operating in the 387-390 MHz band 26 4.1 RAS. 26 4.2 MSS 27 4.3 Compatibility threshold 29 4.4 Interference assessment 29 4.5 Mitigation techniques . 33 *Syria reserves i
4、ts right not to accept any proposed protection criteria contained in this Report, as a result of the use of allocated frequency bands for FSS, RNSS, MSS and BSS in adjacent bands to the radio astronomy service. *The Arab Administrations represented at RA-03 indicated that they do not accept the cont
5、ent of Recommendation ITU-R RA 769, which is referenced in this Report. 2 Rep. ITU-R SM.2091 Page 5 Compatibility analysis between RAS systems operating in the 406.1-410 MHz band and mobile-satellite service (space-to-Earth) systems operating in the 400.15-401 MHz band 34 5.1 RAS. 34 5.2 MSS 34 5.3
6、Compatibility threshold 35 5.4 Interference assessment 36 5.5 Mitigation techniques . 42 6 Compatibility analysis between RAS systems operating in the 608-614 MHz band and broadcasting-satellite service (space-to-Earth) systems that may operate in the 620-790 MHz band. 43 6.1 RAS. 43 6.2 BSS . 44 6.
7、3 Compatibility threshold 46 6.4 Interference assessment 47 6.5 Mitigation techniques . 50 7 Compatibility analysis between RAS systems operating in the 1 400-1 427 MHz and 1 610.6-1 613.8 MHz bands and non-GSO mobile-satellite service (space-to-Earth) systems operating in the 1 525-1 559 MHz band .
8、 51 7.1 RAS. 51 7.2 MSS 54 7.3 Compatibility threshold 59 7.4 Interference assessment 59 7.5 Mitigation techniques for the RAS . 65 7.6 Results of studies 66 8 Compatibility analysis between RAS systems operating in the 1 400-1 427 MHz band and BSS (space-to-Earth) systems operating in the 1 452-1 4
9、92 MHz band 66 8.1 RAS. 66 8.2 BSS . 69 8.3 Compatibility threshold 69 8.4 Interference assessment 69 8.5 Mitigation techniques . 72 8.6 Results of studies 73 Rep. ITU-R SM.2091 3 Page 9 Compatibility analysis between the RAS in the 1 400-1 427 MHz band and GSO mobile-satellite systems (space-to-Ear
10、th) operating in the 1 525-1 559 MHz band 73 9.1 RAS. 73 9.2 MSS 75 9.3 Compatibility threshold 76 9.4 Interference assessment 76 9.5 Mitigation techniques . 77 9.6 Results of studies 78 10 Compatibility analysis between RAS systems operating in the 1 610.6-1 613.8 MHz band and RNSS systems operatin
11、g in the 1 559-1 610 MHz band 78 10.1 RAS. 78 10.2 RNSS 80 10.3 Compatibility threshold 92 10.4 Interference assessment 92 10.5 Mitigation methods. 99 10.6 Results of studies 100 11 Compatibility analysis between RAS systems operating in the 1 610.6-1 613.8 MHz band and MSS (space-to-Earth) systems
12、operating in the 1 613.8-1 626.5 MHz band 101 11.1 RAS. 101 11.2 MSS 103 11.3 Compatibility threshold 103 11.4 Interference assessment 103 11.5 Mitigation techniques . 104 11.6 Results of studies 105 12 Compatibility analysis between RAS systems operating in the 1 610.6-1 613.8 MHz band and GSO MSS
13、(space-to-Earth) systems operating in the 1 525-1 559 MHz band 106 12.1 RAS. 106 12.2 MSS 107 12.3 Compatibility threshold 108 12.4 Interference assessment 109 12.5 Mitigation techniques . 110 12.6 Results of studies 110 4 Rep. ITU-R SM.2091 Page 13 Compatibility analysis between the RAS systems (sp
14、ace-to-Earth) operating in the 2 690-2 700 MHz band and the BSS, and FSS (space-to-Earth) systems operating in the 2 655-2 690 MHz band. 111 13.1 RAS. 111 13.2 Active band. 113 13.3 Compatibility threshold 114 13.4 Interference assessment 114 13.5 Mitigation techniques . 116 13.6 Results of studies
15、117 14 Compatibility analysis between RAS systems operating in the 10.6-10.7 GHz band and FSS (space-to-Earth) systems operating in the 10.7-10.95 GHz band 118 14.1 RAS. 118 14.2 FSS 119 14.3 Compatibility threshold 119 14.4 Interference assessment 119 14.5 Mitigation techniques . 127 14.6 Results o
16、f studies 129 15 Compatibility analysis between RAS systems operating in the 22.21-22.5 GHz band and BSS (space-to-Earth) systems operating in the 21.4-22 GHz band. 130 15.1 RAS. 130 15.2 BSS . 132 15.3 Compatibility threshold 133 15.4 Interference assessment 133 15.5 Mitigation methods. 133 15.6 Re
17、sults of studies 134 16 Compatibility analysis between RAS systems operating in the 42.5-43.5 GHz band and FSS and BSS (space-to-Earth) systems operating in the 41.5-42.5 GHz band . 134 16.1 RAS. 134 16.2 FSS and BSS. 138 16.3 Compatibility threshold 140 16.4 Interference assessment 140 16.5 Mitigat
18、ion techniques . 141 16.6 Results of studies 144 Rep. ITU-R SM.2091 5 1 Introduction The passive radio astronomy service (RAS) is studying natural phenomena producing radio emissions at frequencies fixed by the laws of nature. Primary allocations have been made to various space services in the Earth
19、-to-space direction such as the fixed-satellite service (FSS), radionavigation-satellite service (RNSS), mobile-satellite service (MSS) and broadcasting-satellite service (BSS) in bands adjacent or nearby to bands allocated to the RAS. The studies in this technical report provide methodology and fra
20、mework for documenting the results of the interference assessment between active services and theRAS operating in adjacent and nearby bands. The methodology is based on the equivalent power flux-density (epfd) concept for calculation of interference resulting from unwanted emissions from non-GSO sat
21、ellite systems. The list of bands that were considered under this study is given in Table 1. The result of these studies can be found in the following sections of this Report. TABLE 1 List of compatibility studies with the RAS (passive) RAS bands Active service bands 150.05-153.0 MHz 137-138 MHz (no
22、n-GSO MSS)322-328.6 MHz 387-390 MHz (MSS)406.1-410 MHz 400.15-401 MHz (non-GSO MSS)608-614 MHz 620-790 MHz (BSS) 1 400-1 427 MHz 1 452-1 492 (BSS) 1 400-1 427 MHz 1 525-1 559 MHz (MSS)1 610.6-1 613.8 MHz 1 559-1 610 MHz (RNSS)1 610.6-1 613.8 MHz 1 613.8-1 626.5 MHz (MSS)1 610.6-1 613.8 MHz 1 525-1 5
23、59 MHz (non-GSO MSS)2 690-2 700 MHz 2 655-2 690 MHz (BSS, FSS)10.6-10.7 GHz 10.7-10.95 GHz (FSS)22.21-22.5 GHz 21.4-22 GHz (BSS) 42.5-43.5 GHz 41.5-42.5 GHz (BSS, FSS)2 Methodology 2.1 General The following general methodology defines a systematic means for deriving mutually acceptable compatibility
24、 criteria between operators of active and passive services operating in their allocated bands. The flow diagram (see Fig. 1) summarizes the methodology with each individual step described in detail in 2.2 below. As the procedure is iterative, several cycles might be required before a solution is fou
25、nd. 6 Rep. ITU-R SM.2091 FIGURE 1 Process for the evaluation of adjacent and nearby band operation of passive and active services Rep. ITU-R SM.2091 7 The first step is to determine the transmission parameters of the active service (box (i). The starting point is the worst-case scenario that is used
26、 to determine whether there is the potential for detrimental interference to passive services by any and all types of active services operating in an adjacent or nearby band. This worst-case power level could often be determined from existing regulatory limits (box (1), such as the pfds found in Art
27、icle 21 of the Radio Regulations (RR). Such regulatory limits for the power transmitted by the active service must then be used to determine the worst-case level of unwanted emission into the passive band (box (ii). The following step is to determine if this worst-case interference level is higher t
28、han the passive service interference threshold for the band under consideration (diamond (a). These threshold levels are given in various ITU-R Recommendations (box (2) such as Recommendations ITU-R RA.769, or ITU-R RS.1029. If this interference threshold is higher than the worst-case level of unwan
29、ted emissions in the band, then there is no adverse impact to the passive service operations. In this case the methodology follows the “Yes” line and the process terminates. At this point, as at all other end points in the methodology, the assumptions used to achieve the end point form the technical
30、 basis for a compatible working arrangement between the active and passive services involved. How these technical assumptions and their resulting conclusions are used is a regulatory exercise and is beyond the technical scope of this Recommendation. However, for the case of diamond (a), if the inter
31、ference is assessed to be greater than the passive service criteria, then it is necessary to follow the “No” branch to diamond (b). On the first iteration, no new information is available so the path continues to box (iii). On later iterations, the threshold in diamond (b) may be different from the
32、passive service criteria used in diamond (a) as a consequence of modified or additional parameters and burden sharing. These modified or additional parameters may result from diamonds (c), (d) or (e). Diamond (b) allows a further assessment whether compatibility has been achieved. If such is the cas
33、e the process follows along the “Yes” branch, and the procedure ends. If such is not the case, the discrepancy has to be assessed, whereby in reaching diamonds (c), (d) or (e) the following alternatives should be investigated: refine the emission parameters of the active service such as the actual s
34、ystem parameters, available prime power, etc. and/or; refine the reception parameters in the passive band, and/or; develop further mitigation techniques for both the active and passive services, which may include both alternatives (a) and (b). When during the assessment of discrepancies, as indicate
35、d in box (iii), it is shown that the divergence between the two levels is large, then it is clear that the assumptions used in the first iteration are insufficient to resolve the issue and more detailed assumptions about the characteristics and operations of both services must be made. However, if t
36、he divergence is small, it may be possible to modify slightly one of the underlying assumptions so as to enable converging on a solution on the next iteration. A review of the data at hand may suggest what additional assumptions might be beneficial. From this consideration, either one or more of the
37、 active service parameters, passive service parameters, the compatibility criteria or possible mitigation methods can be considered for modification in successive iterations. As many iterations will take place as necessary to either completely close the gap or to have exhausted all potential solutio
38、ns. If all possible solutions have been exhausted and no compatible operation appears to be possible, then the method ends with a “consultative solution”. This implies that the only possible solution is for a specific active system to consult with a specific passive service system operator, in order
39、 to achieve a one-to-one solution, if that is possible. Specifics of such a consultative solution are outside the purview of this Recommendation. 8 Rep. ITU-R SM.2091 This methodology only addresses the potential interference from a single active service operating in its allocated band. Noting that
40、Earth exploration-satellite service (EESS) (passive) may receive interference simultaneously from multiple services, additional consideration may be required to account for the aggregate effects of multiple active services. 2.2 Detailed description of the flow chart (see Fig. 1) 2.2.1 Box (1): Exist
41、ing ITU documents This box refers to documents that may be relevant for determining transmitter emissions. The following Articles of the RR and ITU-R Recommendations and Reports are relevant to determining transmitter power that may fall into passive bands, and are provided for reference. These regu
42、lations and recommendations are to be used as the starting point in the evaluation of potential active service unwanted emissions into passive service bands. Radio Regulations Articles 1, 5, 21, 22 and Appendix 3. ITU-R Recommendations ITU-R F.758: Considerations in the development of criteria for s
43、haring between the terrestrial fixed service and other services ITU-R F.1191: Bandwidths and unwanted emissions of digital fixed-service systems ITU-R SM.326: Determination and measurement of the power of amplitude-modulated radio transmitters ITU-R SM.328: Spectra and bandwidth of emissions ITU-R S
44、M.329: Unwanted emissions in the spurious domain ITU-R SM.1446: Definition and measurement of intermodulation products in transmitter using frequency, phase, or complex modulation techniques ITU-R SM.1539: Variation of the boundary between the out-of-band and spurious domains required for the applic
45、ation of Recommendations ITU-R SM.1541 and ITU-R SM.329 ITU-R SM.1540: Unwanted emissions in the out-of-band domain falling into adjacent allocated bands ITU-R SM.1541: Unwanted emissions in the out-of-band domain. Some data may be needed beyond what these Recommendations provide. This includes: the
46、 duty cycle of the systems; the geographic distribution and densities of the emitters including deployment densities; the antenna aiming or scanning for radiodetermination systems or Earth-to-space transmissions; the beam coverage for space-to-Earth transmissions; relevant spectral masks; and antenn
47、a patterns. Not all of the required data may be available. for all items listed above. Assumptions may be necessary for some parameters. Other information such as deployment may require the development of models. Rep. ITU-R SM.2091 9 2.2.2 Box (2): Existing ITU documents This box refers to documents
48、 relevant to the selection of the appropriate passive service criteria for protection from interference. The various passive service criteria, each developed by the working party responsible for the respective passive services, serve as the input of diamond (a) on the flowchart. These Recommendation
49、s have been developed, over time, in order to assist other working parties dealing with active services in evaluating the potential for interference from their respective services into the passive services. The list of Recommendations to be considered is as follows: ITU-R Recommendations ITU-R RA.769: Protection criteria used for radio astronomical measurements ITU-R RA.1513: Levels of data loss to radio astronomy observations and percentage-of-time criteria resulting from degradation by interference for frequency bands allocated to the radio astronomy on
