1、 Recommendation ITU-R S.1673-1(01/2010)Methodologies for the calculationof the worst-case interference levelsfrom a non-geostationary HEO-typefixed-satellite service system into geostationary fixed-satellite servicesatellite networks operating in the 10 to 30 GHz frequency bandsS SeriesFixed-satelli
2、te serviceii Rec. ITU-R S.1673-1 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 ra
3、nge on the 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-
4、R policy 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 Guide
5、lines for 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, archiva
6、l and play-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 applic
7、ations and 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 Engli
8、sh under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2010 ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R S.1673-1 1 RECOMMENDATION ITU-R S.1673-1 Methodologies for th
9、e calculation of the worst-case interference levels from a non-geostationary HEO-type fixed-satellite service system*into geostationary fixed-satellite service satellite networks operating in the 10 to 30 GHz frequency bands (Question ITU-R 231/4) (2003-2010) Scope This Recommendation provides metho
10、dologies to assess worst-case interference levels from a non-geostationary HEO-type system operating in the fixed-satellite service into a geostationary satellite network operating in the same service. The methodologies described in this Recommendation are applicable in the 10 to 30 GHz frequency ba
11、nds. These methodologies use worst-case assumptions that overestimate the actual levels of interference. The ITU Radiocommunication Assembly, considering a) that many FSS frequency bands may be used for both GSO and non-GSO satellite networks in accordance with the Radio Regulations (RR); b) that no
12、n-GSO FSS systems shall not cause unacceptable interference to GSO FSS networks in accordance with the provisions of the RR; c) that in some FSS frequency bands, the level of acceptable interference from non-GSO systems to GSO networks has been quantified in terms of epfd and epfd limits and those l
13、imits are specified in RR Article 22 for particular frequency bands; d) that administrations may need to calculate the interference levels, including the worst-case interference level, that are generated from a non-GSO system into any GSO network in the FSS frequency bands other than those for which
14、 epfd and epfd limits are specified in the RR; e) that methodologies have been developed considering the provisions of the RR for the evaluation of interference levels from non-GSO systems to GSO networks; f) that the methodologies referred to in considering e) were based mainly on low- and medium-a
15、ltitude circular orbit non-GSO FSS systems and a more simplified methodology might be appropriate for the calculation of interference from non-GSO HEO-type FSS systems (see Note 1), in which limited portions of the orbit are used as “active” arcs for operation which are spatially separated from the
16、GSO, into GSO FSS networks, recognizing a) that Section II of RR Article 22 addresses “Control of interference to geostationary-satellite systems”, *See Recommendation ITU-R S.1758 for a characterization of high Earth orbit type (HEO-type) systems in the FSS. 2 Rec. ITU-R S.1673-1 noting a) that stu
17、dies on implementation of non-GSO HEO-type FSS systems in the 10 to 30 GHz frequency range have also been made; b) that in frequency bands other than those referred to in considering c) above it is up to the affected administrations to determine whether a non-GSO FSS system is causing unacceptable i
18、nterference to a GSO FSS network; c) that the non-GSO HEO-type FSS systems referenced in noting a) are characterized by the use of limited operational or “active” arcs that, while differing in size from system-to-system, are spatially separated from the GSO, recommends 1 that the worst-case interfer
19、ence level, from a non-GSO HEO-type FSS system described in the noting above into a GSO FSS network, be calculated by considering that all co-frequency non-GSO satellites in such a system that are transmitting towards the same geographic region of the Earth are producing their maximum pfd levels; 2
20、that for non-GSO HEO-type FSS systems in some frequency bands between 10 and 30 GHz where epfd and epfd limits are not specified within the RR (see Note 2), the methodology in Annex 1 to this Recommendation should be used for the calculation of the worst-case levels of interference into GSO FSS netw
21、orks from these non-GSO HEO-type FSS systems (see Notes 3, 4 and 5); 3 that for non-GSO HEO-type FSS systems in some frequency bands between 10 and 30 GHz where epfd and epfd limits are specified within the RR (see Note 2), the methodology in Annex 2 to this Recommendation should be used for the cal
22、culation of the worst-case levels of interference into GSO FSS networks from these non-GSO HEO-type FSS systems (see Notes 4 and 6). NOTE 1 For the purpose of this Recommendation a satellite system using either of the following orbits is categorized as a non-geostationary HEO-type satellite system.
23、Satellites in the system are operational only in the active arc: an orbit with an eccentricity of at least 0.05, an inclination between 35 and 145, an apogee of at least 18 000 km, and a period that is the geosynchronous period (23 h, 56 min) multiplied by m/n where m and n are integers (the ratio m
24、/n may be less than, equal to, or greater than one); or a circular orbit (with an eccentricity of at most 0.005), with the geosynchronous period (23 h, 56 min) and an inclination between 35 and 145. NOTE 2 The frequency bands for which epfd and epfd limits are specified in the RR are 10.7-13.25, 13.
25、75-14.5, 17.3-18.6, 19.7-20.2, 27.5-28.6 and 29.5-30.0 GHz. NOTE 3 The methodology in Annex 1 is complementary to the methodology in Recommendation ITU-R S.1560 for the 4 and 6 GHz frequency bands. NOTE 4 The methodologies in this Recommendation use worst-case assumptions that overestimate the actua
26、l levels of interference. For some systems, especially those with variations in beam pointing, frequency, power, path loss, and/or number of satellites simultaneously illuminating a service area, the overestimation could be considerable. More refined analysis techniques could be used to assess the i
27、nterference profiles in more detail in order to determine realistic interference levels and their associated probabilities of occurrence. NOTE 5 Annex 3 gives an example of the use of the methodology in recommends 2 for a non-GSO HEO-type FSS system. Rec. ITU-R S.1673-1 3 NOTE 6 Annex 4 gives an exa
28、mple of the use of the methodology in recommends 3 for a non-GSO HEO-type FSS system. Annex 1 Methodology for the calculation of the worst-case interference levels from a non-geostationary HEO-type FSS system into geostationary FSS networks operating in some frequency bands between 10 and 30 GHz whe
29、re epfd and epfd limits are not specified in the RR The following methodology should be used for the calculation of the potential levels of interference from the co-frequency operation of non-GSO HEO-type FSS systems into GSO FSS networks operating in some frequency bands between 10 and 30 GHz where
30、 epfd and epfd limits are not specified in the RR. 1 Data concerning the non-GSO FSS system The following information is required concerning the non-GSO FSS system: Space-to-Earth transmissions D-min: Minimum angular separation at a GSO FSS earth station between the LoS to the active transmitting no
31、n-GSO satellites and the LoS to the associated GSO satellite (degrees). pfdD-non-GSO-max:Maximum pfd at the location on the Earths surface of the earth station of the GSO FSS network caused by transmissions from each non-GSO satellite in the constellation (dB(W/(m2 Hz). ND: Maximum number of co-freq
32、uency non-GSO satellites in a satellite system using HEOs transmitting towards the same geographic region of the Earth. An indication of the number of such satellites as a function of the percentage of time is needed. Earth-to-space transmissions U-min: Minimum angular separation at a transmitting n
33、on-GSO FSS earth station between the LoS to the GSO orbit and the LoS to the associated non-GSO satellite (degrees). e.i.r.pnon-GSO-max: Maximum off-axis e.i.r.p. spectral density from the transmitting non-GSO earth station corresponding to the minimum angular separation (U-min) (dB(W/Hz). NU: Maxim
34、um number of co-frequency transmitting non-GSO earth stations in a satellite system using HEOs within a geographic region of the Earth that is likely to be received by a single GSO satellite receive beam. 4 Rec. ITU-R S.1673-1 2 Data concerning the GSO FSS network The following information is requir
35、ed concerning the GSO network: Receive earth station sensitivity GGSO-ES-max: The assumed maximum off-axis gain of the GSO receive earth station in the direction corresponding to the minimum angular separation (D-min) of the non-GSO satellite when it is actively transmitting (dBi). TGSO-ES: Assumed
36、clear-sky receive system noise temperature (including receive antenna noise) of the GSO downlink. To err on the conservative side this need not include degradations caused to the overall link resulting from the uplink (K). Satellite receive sensitivity GGSO-SS-max: Assumed maximum GSO satellite rece
37、ive antenna gain (dBi). TGSO-SS: Assumed clear-sky receive system noise temperature of the GSO uplink. To err on the conservative side this need not include the overall link including downlink (K). 3 Calculation of downlink interference into the GSO network The following three steps are performed to
38、 calculate the degradation to the GSO network downlink receive system noise temperature from one non-GSO satellite system: Step D1: Calculate the maximum interfering signal power spectral density (PSD) (I0-ES) from a single non-GSO satellite at the GSO earth station antenna output: +=4log102-0 maxES
39、GSOmaxGSOnonDESGpfdI dB(W/Hz) (1) where is the wavelength (m). Step D2: Calculate the noise PSD (N0) at the GSO earth station antenna output: )log(10-0 ESGSOESTkN = dB(W/Hz) (2) where k is Boltzmanns constant. Step D3: Calculate the degradation to downlink receive system noise temperature (T/TD) fro
40、m the constellation of non-GSO satellites: =10-0-010/ESESNIDDNTT (3) Rec. ITU-R S.1673-1 5 4 Calculation of uplink interference into the GSO FSS network The following four steps are performed to calculate the degradation to the GSO network uplink receive system noise temperature due to interference
41、from one non-GSO FSS system: Step U1: Calculate the maximum pfd spectral density (spfd) at the GSO space station (pfdU-non-GSO-max) from a single non-GSO transmitting earth station: Note that this equation assumes that the non-GSO transmitting earth station is located at the minimum distance from a
42、GSO satellite. It should be noted that at this earth station location, the resultant separation angle will be greater than the minimum separation angle that is used in the analysis. Thus, this will overestimate the interference that is received. 60)78635(4(log10.2-=maxGSOnonmaxGSOnonUpriepfd dB(W/(m
43、2 Hz) (4) Step U2: Calculate the interfering signal PSD (I0-SS) at the GSO space station antenna output: +=4log102-0 maxSSGSOmaxGSOnonUSSGpfdI dB(W/Hz) (5) where is the wavelength (m). Step U3: Calculate the noise PSD (N0) at the GSO space station antenna output: )log(10-0 SSGSOSSTkN = dB(W/Hz) (6)
44、where k is Boltzmanns constant. Step U4: Calculate degradation to uplink receive system noise temperature (T/TU): =10-0-010/SSSSNIUUNTT (7) 5 Multiple non-GSO FSS systems The above methodology is useful for the calculation of a single entry interference from a system. The methodology, if applied to
45、the situation where there are M multiple non-GSO FSS systems of this type which share the same frequency bands, is not appropriate because the maximum interfering signal PSD levels from the non-GSO FSS systems and the minimum angular separation from the GSO arc may be different among systems. To app
46、ly the principle of the aforementioned methodology to the multiple non-GSO FSS system case, the following should be considered: After steps D1 and U2, aggregate interfering signal PSD levels in downlink and uplink should be calculated by the summation of each single entry levels from M multiple non-
47、GSO FSS systems, respectively as follows: Step D1m: Calculate the maximum aggregate interfering signal PSD, (IA-0-ES) (dB(W/Hz), from non-GSO satellites in the M multiple non-GSO systems at a GSO FSS the earth station antenna output: =MmIESAmESI110-0-010log10 dB(W/Hz) (8) 6 Rec. ITU-R S.1673-1 I0-ES
48、-m is the maximum aggregate interfering signal PSD from non-GSO satellites in the m-th non-GSO system. This is obtained by using the following equation: mDESmESNII-0-0log10+= dB(W/Hz) (9) ND-mis the maximum number of co-frequency satellites in the m-th non-GSO FSS system using HEOs transmitting towa
49、rds the same geographic region of the Earth. Step D3m: T/TDmin the case of N multiple non-GSO FSS systems can be calculated as follow by using the values which are obtained using steps D1m and D2. =10-0-0-10ESESANIDmTT(10) Step U2m: Calculate the maximum aggregate interfering signal PSD (IA-0-SS) (dB(W/Hz) from earth stations in the M multiple non-GSO systems at the GSO space station antenna output: =
