1、 Rec. ITU-R S.1718 1 RECOMMENDATION ITU-R S.1718 Power flux-density values in the band 11.7-12.7 GHz and associated calculation methodology which may be used when the power flux-density values in 6 of Annex 1 to Appendix 30 of the Radio Regulations are exceeded (Question ITU-R 236/4) (2005) Scope Se
2、ction 6 of Annex 1 to RR Appendix 30 provides power flux-density (pfd) values to determine if a proposed BSS network in one Region needs to coordinate with an FSS network in another Region, in the frequency band 11.7-12.7 GHz. The mask in that section provides the envelope of pfd values to trigger c
3、oordination with a wide range of FSS earth station antenna sizes. This Recommendation gives a table of levels equivalent to those in 6 of Annex 1 to RR Appendix 30 for particular combinations of FSS earth station antenna size and system noise temperature, and also describes the methodology by which
4、these levels were computed and a methodology to determine such levels for other earth station antenna sizes by interpolation. The ITU Radiocommunication Assembly, considering a) that systems in the FSS and the BSS have allocations in the band 11.7-12.7 GHz; b) that the use of this band by the planne
5、d BSS is subject to the coordination procedure of Article 4 of Appendix 30 of the Radio Regulations (RR) and to the coordination requirements contained in the “Remarks” column in Article 11 of RR Appendix 30; c) that 6 of Annex 1 to RR Appendix 30 provides thresholds to determine if there is a need
6、to coordinate planned BSS networks in one region with respect to FSS networks in another region in the band 11.7-12.7 GHz, further considering a) that pfd values in 6 of Annex 1 to RR Appendix 30 are thresholds to determine if coordination is required between a planned BSS network operating in one r
7、egion with respect to an FSS network in another region; b) that such threshold values should necessarily be protective of FSS links with a wide range of technical characteristics; c) that 6 of Annex 1 to RR Appendix 30 also provides a pfd mask which corresponds to the envelope of the permissible int
8、erfering pfd into the range of GSO FSS earth station antenna sizes used in the 11.7-12.7 GHz band; d) that technical information is needed to address instances when the pfd values in 6 of Annex 1 to RR Appendix 30 are exceeded and coordination of the corresponding BSS assignments with FSS assignment
9、s is necessary, 2 Rec. ITU-R S.1718 recommends 1 that in cases where, as a result of the application of Article 4 of RR Appendix 30 or the coordination requirements contained in the “Remarks” column in Article 11 of RR Appendix 30, the pfd values in 6 of Annex 1 to RR Appendix 30 are exceeded, the p
10、fd values given in Table 1 may be used by administrations, during their bilateral or multilateral coordination of their BSS assignments with FSS assignments, to identify levels equivalent to those in 6 of Annex 1 to RR Appendix 30 for particular antenna sizes (see also Notes 1 to 10); 2 that, notwit
11、hstanding recommends 1, the pfd level produced at the surface of the Earth within the service area of the affected FSS assignment by a planned BSS network operating in another region should not exceed 103.6 dB(W/(m2 27 MHz). TABLE 1 Applicable pfd values (dB(W/(m2 27 MHz) corresponding to various FS
12、S antenna sizes Antenna size (cm) 45 (see Note 5) 60 80 120 240 500 800 1 100 Orbital separation between wanted and interfering space stations pfd values (dB(W/(m2 27 MHz) = 0 134.2 136.7 138.7 141.4 147.4 152.5 155.6 158.4 0 See Note 3 and Table 2 of Annex 1 NOTE 1 The applicable pfd value should b
13、e derived from Table 1 using the antenna diameters calculated from the maximum antenna gains as given in the RR Appendix 4 information provided to the Bureau under RR No. 9.30 for the affected FSS assignment in question. NOTE 2 In calculating the compliance of the pfd levels produced by the interfer
14、ing BSS network with those given in Table 1, the affected FSS receive earth station antenna should be assumed to be compliant with the antenna pattern specified in Recommendation ITU-R BO.1213, extrapolated to the relevant frequency within the 11.7-12.7 GHz band, for antennas of 2.4 m in diameter or
15、 less, and with the antenna pattern specified in 3 of Annex 3 to RR Appendix 7, for antennas of more than 2.4 m in diameter. NOTE 3 In calculating the compliance of the pfd levels produced by the interfering BSS network with those given in Table 1, the minimum orbital separation between the wanted a
16、nd interfering networks should be assumed, including the station-keeping accuracies. For any value of the orbital separation between the wanted and interfering space stations, the applicable pfd should be relaxed from the value corresponding to 0 orbital separation by adding the off-axis antenna dis
17、crimination, as calculated under the assumptions in Note 2. NOTE 4 For FSS antenna diameters different from those in Table 1, the method given in Annex 2 is an example of possible way to interpolate. NOTE 5 The values for less than 60 cm antenna diameter are only applicable for Region 3 FSS networks
18、 in the orbital arc 110 E-124 E with respect to assignments in the Regions 1 and 3 List in the orbital arc 105 E-129 E: for which RR Appendix 4 information for coordination had been received by the Bureau prior to 30 March 2002; and Rec. ITU-R S.1718 3 which had been brought into use prior to 30 Mar
19、ch 2002 and for which the date of bringing into use had been confirmed to the Bureau; and for which the complete due diligence information, in accordance with Annex 2 to Resolution 49(Rev.WRC-2000), had been received by the Bureau prior to 30 March 2002. NOTE 6 The values in Table 1 may be exceeded
20、by mutual agreement between the concerned administrations. NOTE 7 This Recommendation and the associated methodology do not release administrations from their coordination obligation under Articles 4 and 11 of RR Appendix 30. NOTE 8 The pfd values in Tables 1 and 2 in Annex 1 were derived using the
21、methodology contained in Annex 1 and assuming a 6% noise increase interference allowance, a frequency of 11.7 GHz, an antenna efficiency of 65%, and total link noise temperature values of 174 K for antennas with up to 60 cm diameter, 198 K for 80 cm diameter, 238 K for 120 cm and 240 cm, 317 K for 5
22、00 cm, and 396 K for 800 cm or more. During coordination between concerned administrations, other values for link noise temperature increase and link noise temperature may be considered. NOTE 9 As the FSS also uses narrow-band transmissions the pfd should be expressed in units of dB(W/(m2 40 kHz). T
23、his requires reducing the pfd value by 10 log(27 000/40) = 28.3 dB. NOTE 10 This Recommendation is not intended to be used by the Bureau in its analysis of networks to determine whether or not the criteria in Annex 1 of RR Appendix 30 are exceeded. Annex 1 Methodology to calculate pfd levels for FSS
24、 networks using particular earth station antenna sizes for use when the trigger levels in 6 of Annex 1 to RR Appendix 30 are exceeded 1 Description of the methodology The pfd required to protect an interfered-with FSS network is related to the receive earth station antenna gain and total link noise
25、temperature of the interfered-with FSS network by the following formula: pfd () = 10 log(T/T) + 10 log(k T bref) + 10 log(4/(0.3/f)2) Ga() (1) where: : orbital separation between interfered-with and interfering satellites (see Note 3) : topocentric angle between the interfered-with and interfering s
26、atellites at the wanted receiving antenna (degrees) T/T: allowable relative increase in total receive link noise temperature (%) k: Boltzmanns constant (1023J K1) T:total receive link noise temperature (K) bref: reference bandwidth (27 MHz) (see Note 9 of recommends 2) 4 Rec. ITU-R S.1718 Ga(): rece
27、ive antenna gain for topocentric angle of (dBi) f: frequency of the interfered-with and interfering signals (GHz). Note that for a specified (T/T), bref, and T, the allowable interfering pfd is only a function of the receive antenna gain which is a function of satellite orbital separation. 2 Applica
28、tion of the methodology to obtain the levels of pfd specified in Table 2 This methodology is used for calculating the pfd values that protect FSS networks with antenna sizes ranging from 45 cm to 11 m from interfering BSS networks with given orbital separation angles, with the assumptions given in N
29、otes 2 and 8 of the Recommendation and assuming = 1.1 . The corresponding values for these cases are given in Table 2 below, which correspond to the pfd values given in Table 1 for = 0. The link noise temperature values which have been used to derive these values are also given in Table 2. TABLE 2 A
30、pplicable pfd values dB(W/(m2 27 MHz) corresponding to various FSS antenna sizes and orbital separations Separation angles () 45 cm antennaT = 174 K60 cm antenna T = 174 K 80 cm antennaT = 198 K120 cm antennaT = 238 K240 cm antennaT = 238 K500 cm antennaT = 317 K800 cm antenna T = 396 K 1 100 cm ant
31、ennaT = 396 K0.01 134.2 136.7 138.7 141.4 147.4 152.5 155.6 158.4 0.10 134.2 136.7 138.7 141.3 147.2 151.4 152.7 152.9 0.50 134.0 136.3 137.9 139.7 140.8 132.0 133.2 133.2 1.00 133.3 135.1 135.7 134.8 127.9 126.6 125.7 125.7 1.50 132.1 133.0 132.1 126.5 123.5 122.2 121.3 121.3 2.00 130.5 130.1 126.9
32、 120.4 120.4 119.1 118.2 118.2 2.50 128.4 126.4 120.3 117.9 117.9 116.7 115.7 115.7 3.00 125.9 121.8 116.8 116.0 116.0 114.7 113.8 113.8 3.50 122.8 116.5 115.1 114.3 114.3 113.0 112.1 112.1 4.00 119.3 114.2 113.6 112.8 112.8 111.6 110.6 110.6 5.00 111.8 111.8 111.2 110.4 110.4 109.2 108.2 108.2 6.00
33、 109.8 109.8 109.2 108.4 108.4 107.2 106.2 106.2 7.00 108.1 108.1 107.6 106.8 106.8 105.5 104.6 104.6 8.00 106.7 106.7 106.1 105.3 105.3 104.1 103.1(1)103.1(1)9.00 105.4 105.4 104.8 104.0 104.0 102.8(1)101.8(1)101.8(1)10.00 104.3 104.3 103.7 102.9(1)102.9(1)101.6(1)100.7(1)100.7(1)11.00 103.2(1)103.
34、2(1)102.7(1)101.9(1)101.9(1)100.6(1)99.6(1)99.6(1)12.00 102.3(1)102.3(1)101.7(1)100.9(1)100.9(1)99.7(1)98.7(1)98.7(1)(1)As a result of recommends 2, the value of 103.6 dB(W/(m2 27 MHz) is applicable in this case. Rec. ITU-R S.1718 5 Annex 2 Example methodology for determining the pfd ( = 0) values f
35、or an antenna size not included in Table 1 Step 1: Determination of closest parameters xA, yA,xB, yB from Table 1 and the applicable total link noise temperature, T: If 45 d 60 cm then T= 174 K If 60d 80 cm then T is derived using the equation below with xA = 60, yA = 174,xB = 80, yB = 198 If 80 d 1
36、20 cm then T is derived using the equation below with xA = 80, yA = 198,xB = 120, yB = 238 If 120 d 240 cm then T= 238 K If 240 d 500 cm then T is derived using the equation below with xA = 240, yA = 238,xB = 500, yB = 317 If 500 d 800 cm then T is derived using the equation below with xA = 500, yA
37、= 317,xB = 800, yB = 396 If 800 d 1 100 cm then T= 396 K: T= yA+ (yB yA)(d xA)/(xB xA) Step 2: Determination of the applicable maximum gain, Gmax: Gmax= 10 log(0.65( 0.01d/(0.3/f)2) Step 3: Determination of the applicable pfd ( = 0): pfd ( = 0) = 10 log(6/100) 228.6 + 10 log(T) + 74.3 + 10 log(4/(0.3/f)2) Gmaxwhere: T:total FSS link noise temperature (K) d: diameter of the interfered-with receiving antenna (cm) Gmax: maximum gain of the interfered-with receiving antenna (dBi) f: frequency of the interfered-with and interfering signals (GHz).
