1、 Recommendation ITU-R S.1856(01/2010)Methodologies for determining whether an IMT station at a given location operating in the band 3 400-3 600 MHz would transmit without exceeding the power flux-density limits in the Radio Regulations Nos. 5.430A, 5.432A,.432B and 5.433AS SeriesFixed-satellite serv
2、iceii Rec. ITU-R S.1856 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 range on th
3、e 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-R policy
4、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 Guidelines for
5、 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, archival and pla
6、y-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 applications an
7、d 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 English under
8、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.1856 1 RECOMMENDATION ITU-R S.1856 Methodologies for determining whe
9、ther an IMT station at a given location operating in the band 3 400-3 600 MHz would transmit without exceeding the power flux-density limits in the Radio Regulations Nos. 5.430A, 5.432A, 5.432B and 5.433A (2010) Scope This Recommendation contains three methodologies that may be used by the concerned
10、 administrations, during their bilateral and/or multilateral discussions, in order to determine whether an IMT base or mobile station proposed to operate in the 3 400-3 600 MHz band would meet the pfd limit in the Radio Regulations (RR) Nos. 5.430A, 5.432A, 5.432B and 5.433A. This Recommendation doe
11、s not address the criteria required for the application of RR Nos. 9.17, 9.18 and 9.21 which are mentioned in the above four provisions, irrespective of whether or not any earth station is in operation. The ITU Radiocommunication Assembly, considering a) that, following decisions taken by WRC-07, in
12、 a number of countries in Region 1 the frequency band 3 400-3 600 MHz is allocated to the mobile service on a primary basis (see Radio Regulations (RR) No. 5.430A); b) that, following decisions taken by WRC-07, in a number of countries in Region 3 the frequency band 3 400-3 500 MHz is allocated to t
13、he mobile service on a primary basis (see RR No. 5.432B) while the frequency band 3 500-3 600 MHz has been allocated for many years to the mobile service on a primary basis in Region 3; c) that, at WRC-07, the frequency band 3 400-3 600 MHz was identified for use by IMT systems in a number of countr
14、ies in Regions 1 and 3; d) that for many years the band 3 400-3 600 MHz has been allocated to the fixed-satellite service (space-to-Earth) on a primary basis throughout Regions 1, 2 and 3; e) that, in order to protect earth stations in the band 3 400-3 600 MHz from cross-border interference by stati
15、ons in the mobile service, RR Nos. 5.430A, 5.432A, 5.432B and 5.433A (WRC-07) state that, before an administration specified in these footnotes brings into use a (base or mobile) station of the mobile service in this band it shall ensure that the power flux-density (pfd) produced at 3 m above ground
16、 does not exceed 154.5 dB(W/(m2 4 kHz) for more than 20% of time at the border of the territory of any other administration; f) that the pfd limit in considering e) may be exceeded on the territory of any country whose administration has so agreed; g) that the RR also state that, in order to ensure
17、that the pfd limit at the border of the territory of any other administration is met, the calculations and verification shall be made, taking into account all relevant information, with the mutual agreement of the administration responsible for the terrestrial station and the administration responsi
18、ble for the earth station; 2 Rec. ITU-R S.1856 h) that, since propagation loss increases with distance, and on overland paths is strongly influenced by the nature of the terrain, IMT stations located at a sufficient distance from the neighbouring countrys border may meet the pfd limit without the ap
19、plication of interference mitigation techniques, and therefore methods to identify the areas in a country where this is so would assist administrations to comply with the requirement in considering e); j) that in the application of the methods mentioned in considering h) it may be appropriate to use
20、 a terrain database covering any country in which it is planned to operate IMT stations in the band 3 400-3 600 MHz; k) that natural or man-made site shielding could attenuate the signal transmitted by an IMT station in the direction of a neighbouring countrys border, noting a) that the allocations
21、relating to RR Nos. 5.430A and 5.432B are effective from 17 November 2010, recommends 1 that the method in either 1 or 2 or 3 of Annex 1, or a combination of these methods, as deemed appropriate by the concerned administrations during their bilateral and/or multilateral discussions, may be used for
22、determining whether an IMT base station proposed to operate in the 3 400-3 600 MHz band would meet the pfd limits in RR Nos. 5.430A, 5.432A, 5.432B and 5.433A; 2 that the method described in 2 of the annex may be used to determine the size and shape of the area just inside the border of a country ou
23、tside of which operation of an IMT mobile terminal would meet the pfd limit at 3 m above ground at any point on that border; 3 that the following Note should be considered as part of this Recommendation. NOTE 1 The parameters and the methodology to be used should be agreed by the concerned Administr
24、ations involved in the bilateral and/or multilateral discussions. Annex 1 Methodologies for determining whether a transmit IMT station meets the pfd limits in RR Nos. 5.430A, 5.432A, 5.432B and 5.433A ITU-R has recently developed a Recommendation addressing the calculation of the pfd generated by FS
25、S earth stations transmitting in the band 13.75-14.00 GHz1. As described in 1, 2 and 3 of Annex 1, the methodologies contained in Recommendation ITU-R S.1712 can be adapted for the assessment of compliance with the pfd limit contained in RR Nos. 5.430A, 5.432A, 5.432B and 5.433A2. It is also noted t
26、hat other methodologies beyond adaptations of those in Recommendation ITU-R S.1712 may be appropriate. 1Recommendation ITU-R S.1712 Methodologies for determining whether an FSS earth station at a given location could transmit in the band 13.75-14 GHz without exceeding the pfd limits in No. 5.502 of
27、the Radio Regulations, and guidelines to mitigate excesses. 2The three methods described here are applicable to a fixed base station, while only Method 2 is applicable to a mobile station (see 2.4). Rec. ITU-R S.1856 3 For a number of characteristics used in the methodology described below, the valu
28、es assumed in the examples are illustrative only and, in any particular study, the values used for these characteristics could be expected to reflect the actual characteristics of the IMT stations and other parameters under consideration. 1 Adaptation of Method 1 of Recommendation ITU-R S.1712 Metho
29、d 1 is simple but admittedly overly conservative3. This method produces two curves, using a smooth Earth model, showing the minimum separation distance from a neighbouring countrys land border that an IMT base station would need to meet in order to respect the pfd limits in RR Nos. 5.430A, 5.432A, 5
30、.432B and 5.433A, as a function of the IMT station e.i.r.p. density toward the horizon. The primary curve gives the line-of-sight separation distance. The secondary curve gives the trans-horizon separation distance. An IMT base station deployed at a distance greater than or equal to the minimum sepa
31、ration distance is assumed to meet the pfd limit criterion. Besides determination of whether the path to the border is line-of-sight or trans-horizon, no further analyses are required. Note that deployment in areas excluded by this method is still possible provided a potential site can be shown to m
32、eet the pfd limit criterion through application of an adapted form of Methods 2 or 3 of Recommendation ITU-R S.1712 (see 2 and 3). In order to fully account for the variability of terrain in the real world, Method 1 is separated into three steps of increasing complexity. Step A is by far the simples
33、t and does not account for terrain. In fact, this step assumes a flat Earth where all paths are line-of-sight (LoS). Step B assumes a spherical Earth with a nominal radio horizon but does not consider the effect of intervening terrain. Like Step B, Step C assumes a spherical Earth, but unlike Step B
34、 it does take into consideration the effect of intervening terrain, albeit using a conservative but simplified approach. Each step in order will increase the size of the potential IMT deployment area (exposing the largest area using Step C). It is given that if Step A or Step B shows that a potentia
35、l deployment site meets the pfd limit criterion, then the following step(s) need not be performed. At the discretion of the user, Steps B or C may be employed without previously implementing Step A. In order to calculate the value of the distance, some basic assumptions and propagation models are re
36、quired. Those in Recommendation ITU-R P.452 have been used in many similar sharing situations and would appear to be the most appropriate to be used here. An in-depth description of this method follows: Step A: All paths are assumed to be LoS. The LoS curve in Fig. 1 is used to determine the minimum
37、 separation distance as a function of e.i.r.p./4 kHz radiated by the IMT station towards the border. Note that the curve was derived from the LoS loss from Recommendation ITU-R P.452-12 (p = 20%)4. Since this is a flat Earth model, the curve is independent of factors such as local N and 3 For instan
38、ce, in the United States of America, instead of defining a pfd, a coordination distance of 150 km was defined to ensure the protection of existing FSS earth stations from interference produced by BWA (broadband wireless access) transmitters with an e.i.r.p. density of 25 W/25 MHz. In addition, the U
39、S rules specify a minimum separation distance of 56 km to the Canadian and Mexican borders for fixed stations, unless a shorter distance can be coordinated on a case-by-case basis. The methodology used by the United States of America in the derivation of a coordination distance of 150 km can also be
40、 adapted for application to the pfd calculation being addressed here. 4Recommendation ITU-R P.452-13 is currently in force and the Recommendation might be further updated in the future. If so, when following this methodology in the future, it would be advisable to use the version of Recommendation I
41、TU-R P.452 in force at the time. 4 Rec. ITU-R S.1856 antenna height above terrain. If the potential deployment site is farther from the border than the required separation distance from the LoS curve, then the station is assumed to comply with the pfd limit criterion of RR Nos. 5.430A, 5.432A, 5.432
42、B and 5.433A. If the path length is smaller than the required separation distance, then proceed to Step B. 1856-01Step B: This step assumes a spherical Earth and thus requires the determination of a nominal radio horizon. First, find the effective Earth radius (e) using the local N and equations (5)
43、 and (6) of Recommendation ITU-R P.452-12 (convert to metres). The radio horizon can then be calculated from the following equation: RHorizonnominal= ( ) 0001/20 imtehh + (km) where h0= 3 m, and himtis the IMT station height (m) above mean sea level. If the IMT station site is within the nominal rad
44、io horizon in the direction of the border, then the required separation distance is found using the LoS curve of Fig. 1. If the IMT station site is beyond the nominal radio horizon, then determine the required separation distance using the trans-horizon curve of Fig. 1. If the potential deployment s
45、ite is farther from the border than the required separation distance from the applicable curve, then the station is assumed to comply with the pfd limit criterion of RR Nos. 5.430A, 5.432A, 5.432B and 5.433A. If the path length is smaller than the required separation distance, then proceed to Step C
46、. Step C: This step also assumes a spherical Earth. Furthermore, it requires a more detailed analysis of the paths toward the border. Appendix 2 of Annex 1 of Recommendation ITU-R P.452-12 is used to determine if a path is LoS or trans-horizon. The specific procedure is detailed in 4.1 of that Rec.
47、ITU-R S.1856 5 appendix: “Test for a trans-horizon path”. The terrain data can be taken from digital elevation maps or even derived from the elevation contours of printed maps. Since in actual terrain, the path with the lowest loss is not necessarily the shortest path, several paths in radial around
48、 the potential IMT station site should be tested. If any path is shown to be LoS, then the required separation distance is found using the LoS curve of Fig. 1 (using the shortest LoS path). If the test shows that all paths are trans-horizon, then the required separation distance is found using the r
49、elevant trans-horizon curve of Fig. 1. If the potential deployment site is farther from the neighbouring countrys border than the required separation distance from the applicable curve, then the station is assumed to comply with the pfd limit criterion of RR Nos. 5.430A, 5.432A, 5.432B and 5.433A. If the path length is smaller than the required separation distance, the IMT station is likely to be non-compliant with the pfd limit. It is important to note that the required separation distance found with any of the three steps above may not be an absolute mini
