1、 Rec. ITU-R BO.1658 1 RECOMMENDATION ITU-R BO.1658 Continuous curves of epfdversus the geostationary broadcasting-satellite service earth station antenna diameter to indicate the protection afforded by systems complying with the limits of antennas with diameters other than those in Article 22 of the
2、 Radio Regulations (Resolution 137 (WRC-2000) (2003) The ITU Radiocommunication Assembly, considering a) that the 11.7-12.75 GHz frequency band is available to GSO systems in the BSS and non-GSO systems in the FSS; b) that earth stations in the BSS employing satellites in GSO orbits need to be prote
3、cted from unacceptable interference by satellites in non-GSO orbits transmitting in the shared frequency bands; c) that in order to provide the requisite protection from such interference, WRC-2000 adopted validation single-entry limits on the maximum permissible equivalent power flux densities (epf
4、ds) which satellites in non-GSO orbits may radiate in some frequency bands, for certain specified earth station antenna diameters; d) that the Radiocommunication Bureau will certify compliance with the maximum permissible epfdvalidation limits only for those earth station antenna diameters specified
5、 in Article 22 of the Radio Regulations (RR); e) that, as indicated in Resolution 137 (WRC-2000), there is a need for operators to be able to assess the level of interference generated by a non-GSO system meeting the epfdlimits for earth station antennas with diameters other than those specified in
6、RR Article 22, recommends 1 that the methodology in Annex 1 should be used within the specified context, for the guidance of designers of GSO BSS links on the maximum expected epfd levels for earth station antenna diameters other than those specified in RR Article 22 (see Notes 1, 2 and 3). NOTE 1 I
7、t is emphasised that the continuous curves, as a function of antenna diameter, are strictly in reference to single-entry regulatory limits given for the specific antenna diameters as tabulated in Table 1D of RR Article 22. The guidance to the GSO BSS designers is to be taken in this context: the con
8、tinuous curves provide an approximation of how the regulatory limits of RR Article 22 could appear if they were defined for an arbitrary antenna diameter. In this respect these continuous curves are intended to provide guidelines on the upper boundary of interference that GSO BSS earth stations migh
9、t receive. NOTE 2 The epfdlevels in this Recommendation are referenced to a bandwidth of 40 kHz. To convert to other bandwidths, a correction factor of 10 log(B/40) is added to the value of epfd, where B is the required bandwidth (kHz). 2 Rec. ITU-R BO.1658 NOTE 3 Other significantly improved method
10、s may be developed in the future that could replace the method in this Recommendation. Annex 1 Methodology to derive continuous curves of epfdversus BSS earth station antenna diameter in the frequency band 11.7-12.75 GHz The proposed methodology consists of deriving curves by curve-fitting the valid
11、ation epfdlimits given in RR Table 22-1D applicable for the protection of GSO BSS systems with inclination angles less than 2.5 and for earth stations at latitudes below 57.5. These curves, hereafter referred to as validation limit reference curves, are constructed by linear interpolation between va
12、lues of epfd(dB) and by logarithmic interpolation between values of percentage of time for which the epfdmay be exceeded. These reference validation limits on the basis of which the curve fitting is performed, are described in 1.1. The resulting curves are best approximations and may not completely
13、match the values tabulated in RR Article 22. Examples of such curves for epfdare given in 1.2. 1.1 RR Article 22 validation limits in the frequency band 11.7-12.75 GHz The validation limits for the frequency band 11.7-12.75 GHz are given in terms of the percentage of time during which the epfdlevel
14、may be exceeded. These limits are shown in Table 1. TABLE 1 Limits to the epfdradiated by non-GSO FSS systems in certain frequency bands into 30 cm, 45 cm, 60 cm, 90 cm, 120 cm, 180 cm, 240 cm and 300 cm BSS antennas Frequency band (GHz) epfd(dB(W/m2) Percentage of time during which epfdlevel may be
15、 exceeded Reference bandwidth (kHz) Reference antenna diameter and radiation pattern 11.7-12.5 in Region 1; 11.7-12.2 and 12.5-12.75 in Region 3; 12.2-12.7 in Region 2 165.841 165.541 164.041 158.6 158.6 158.33 158.33 100 75 4.0 1.143 0.571 0.571 0 40 30 cm Recommendation ITU-R BO.1443, Annex 1 Rec.
16、 ITU-R BO.1658 3 TABLE 1 (continued) Frequency band (GHz) epfd(dB(W/m2) Percentage of time during which epfdlevel may be exceeded Reference bandwidth (kHz) Reference antenna diameter and radiation pattern 175.441 172.441 169.441 164 160.75 160 160 100 34 2.25 0.643 0.191 0.014 0 40 45 cm Recommendat
17、ion ITU-R BO.1443, Annex 1 176.441 173.191 167.75 162 161 160.2 160 160 100 2.2 0.629 0.114 0.057 0.029 0.003 0 40 60 cm Recommendation ITU-R BO.1443, Annex 1 178.94 178.44 176.44 171 165.5 163 161 160 160 100 67 2.0 0.571 0.286 0.143 0.057 0.009 0 40 90 cm Recommendation ITU-R BO.1443, Annex 1 182.
18、44 180.69 179.19 178.44 174.94 173.75 173 169.5 167.8 164 161.9 161 160.4 160 100 10 1.1 1.1 0.5 0.32 0.32 0.15 0.085 0.06 0.03 0.01 0.002 0 40 120 cm Recommendation ITU-R BO.1443, Annex 1 11.7-12.5 in Region 1; 11.7-12.2 and 12.5-12.75 in Region 3; 12.2-12.7 in Region 2 184.941 184.101 181.691 176.
19、25 163.25 161.5 160.35 160 160 100 67 1.5 0.429 0.054 0.026 0.007 0.001 0 40 180 cm Recommendation ITU-R BO.1443, Annex 1 4 Rec. ITU-R BO.1658 TABLE 1 (end) 1.2 Continuous curves for validation limits in the frequency band 11.7-12.75 GHz Example continuous curves for epfd(dB(W/(m2 40 kHz), in the 11
20、.7-12.75 GHz frequency band can be defined by the following sigmoid function, for antenna diameters in the range 0.3 to 3 m: .D.DD Dpepfd (2) where: D : antenna diameter (m) p : percentage of time that the value of epfdmay be exceeded, and the coefficients B(D), T(D), V(D), S(D) and ai(D) are given
21、in Table 2 for the antenna sizes specified in RR Table 22-1D. For other antenna sizes, the coefficients are linearly interpolated between the values for antenna sizes enclosing the desired one. Frequency band (GHz) epfd(dB(W/m2) Percentage of time during which epfdlevel may be exceeded Reference ban
22、dwidth (kHz) Reference antenna diameter and radiation pattern 187.441 186.341 183.441 178 164.4 161.9 160.5 160 160 100 67 0.75 0.214 0.043 0.017 0.006 0.001 0 40 240 cm Recommendation ITU-R BO.1443, Annex 1 11.7-12.5 in Region 1; 11.7-12.2 and 12.5-12.75 in Region 3; 12.2-12.7 in Region 2 191.941 1
23、89.441 185.941 180.5 173 167 162 160 160 100 67 0.5 0.143 0.086 0.049 0.017 0.009 0 40 300 cm Recommendation ITU-R BO.1443, Annex 1 Rec. ITU-R BO.1658 5 TABLE 2 Curve fitting parameters for antenna sizes specified in RR Table 22-1D The error in the resulting curves, when compared with the values of
24、epfdin RR Table 22-1D, is at most 1.6 dB and over most (90%) of the range, is within 0.7 dB. This methodology results in a mean square error of 0.173. Figures 1 and 2 show the epfdlimits from RR Table 22-1D together with the resulting curves for the RR Table 22-1D antenna diameters. 1658-01110180175
25、17016516015510110210210345 cm60 cm90 cm45 cm60 cm90 cmPercentage of time epfd may be exceededepfd(dB(W/(m240 kHz)30 cm RR Table 22-1D 30 cm algorithmFIGURE 1RR Table 22-1D epfd levels versus percentage of timeAntenna size (m) a0a1a2a3a4a5B T V S 0.3 142.91 90.436 149.64 120.74 47.081 7.1256 164.4925
26、995 158.3258057 0.33952 0.124770.45 165.83 13.718 15.328 8.4976 1.8108 0.14127 171.3103027 160.0220947 0.03973 0.291170.6 169.64 15.151 22.033 17.113 6.2700 0.87607 175.1157074 159.9786987 0.26004 0.379530.9 173.31 15.968 28.802 26.494 11.584 1.9465 177.6311951 160.0350037 0.36057 0.299661.2 178.75
27、4.7184 8.1693 8.8981 4.2662 0.75080 180.5879974 160.0374146 0.74204 0.386001.8 179.97 12.163 26.496 29.117 14.632 2.7447 183.0420990 159.9929047 0.68604 0.360482.4 183.60 2.3595 4.1759 6.9599 4.7091 1.1081 184.5879974 160.0373993 0.95509 0.311723.0 186.36 3.9419 10.985 18.309 12.388 2.9152 187.08580
28、02 159.9777985 1.0713 0.260386 Rec. ITU-R BO.1658 1658-021101801751701651601551011021021031851901953 m 3 mPercentage of time epfdmay be exceededepfd(dB(W/(m2 40kHz)1.2 m RR Table 22-1D 1.2 m algorithm1.8 m2.4 m1.8 m2.4 mFIGURE 2RR Table 22-1D epfdlevels versus percentage of time1101801751706516015 10102103 epfd, (dB(W(m2 40 kHz) FIGURE 1R Table 22-1D epfd levs vru percntag of time
