1、 Recommendation ITU-R RS.1884(02/2011)Methodology for determining terrestrial and space-to-Earth sharing and coordination criteria for meteorological aidsin the 400.15-406 MHz and1 668-1700 MHz bandsRS SeriesRemote sensing systemsii Rec. ITU-R RS.1884 Foreword The role of the Radiocommunication Sect
2、or 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 the basis of which Recommendations are adopted. The regulatory and policy
3、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 on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC
4、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 Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and
5、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 play-out; film for television BS Broadcasting service (sound) BT Broadcasti
6、ng 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 and meteorology SF Frequency sharing and coordination between fixed-satell
7、ite 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 the procedure detailed in Resolution ITU-R 1. Electronic Publication Gen
8、eva, 2011 ITU 2011 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R RS.1884 1 RECOMMENDATION ITU-R RS.1884 Methodology for determining terrestrial and space-to-Earth sharing and coordination criteria for meteor
9、ological aids in the 400.15-406 MHz and 1 668-1 700 MHz bands (2011) Scope This Recommendation provides information on determining terrestrial and space-to-Earth sharing and coordination criteria for meteorological aids (radiosondes, dropsondes and rocketsondes) operating in the 400.15-406 MHz and 1
10、 668.4-1 700 MHz bands. The ITU Radiocommunication Assembly, considering a) that frequency bands allocated to the meteorological aids service may be shared by systems operating in other services, including the Earth exploration-satellite and meteorological-satellite services; b) that sharing and coo
11、rdination criteria for these systems should relate to the maximum level of interference that can be accepted from an individual interferer; c) that the methodology used to develop sharing and coordination criteria for the Earth exploration-satellite and meteorological-satellite services may be appli
12、ed to systems operating in the meteorological aids service in order to determine acceptable single-entry levels of interference that are greater than or equal to the permissible levels, recommends 1 that the methodology given in Annex 1 should be used for the development of sharing and coordination
13、criteria and in compatibility studies between Earth exploration-satellite and meteorological-satellite services, and meteorological aids service; 2 that the example given in Annex 2 should be used as a guide in implementation of the methodology given in Annex 1; 3 that the interference criteria give
14、n in Recommendation ITU-R RS.1263 for meteorological aids operating in the 400.15-406 MHz and 1 668.4-1 700 MHz bands, should be considered in the development of coordination criteria for the specific systems operating in the Earth exploration-satellite and meteorological-satellite services. 2 Rec.
15、ITU-R RS.1884 Annex 1 Methodology for determining sharing and coordination criteria 1 Initial division of interference criteria In cases involving space and terrestrial services, it is useful to initially divide the permissible level of total interfering signal power (i.e. interference criteria) bet
16、ween interference via terrestrial signal paths (i.e. for earth and terrestrial station transmissions) and space-to-Earth signal paths because the assumed number of interferers and the associated interference statistics usually differ between these two categories of interfering services. In other cas
17、es, this initial division is unnecessary. The initial division is accomplished using the following equations: is (20) = i (20) (As /100) (1a) it (20) = i (20) is (20) (1b) it (pt) = i (p) is (ps) (2a) ps= p (as /100) (2b) pt= p ps(2c) where: i (20) : permissible level of total interfering signal pow
18、er (W) to be exceeded for no more than 20% of the time (i.e. long-term interference criteria) is (20), is (ps) : interfering signal power (W) level budgeted for space-to-Earth signals that is to be exceeded for no more than 20% and ps% of the time, respectively it (20), it (pt) : interfering signal
19、power (W) level budgeted for terrestrial signal paths that is to be exceeded for no more than 20% and pt% of the time, respectively As : percentage of permissible level of total interfering signal power (W) allotted for interference from space-to-Earth signals i (p) : permissible level of total inte
20、rfering signal power (W) to be exceeded for no more than p% of the time (i.e. short-term interference criteria) p : percentage of time associated with the short-term interference criteria ps : percentage of time that space-to-Earth signals may exceed the interference threshold pt : percentage of tim
21、e that signals propagated over terrestrial paths may exceed the interference threshold as : portion of the percentage of time p allotted to interference from space-to-Earth signals. In equations (1a) and (1b), the long-term interference criteria are divided on a power basis among interference catego
22、ries. This is because long-term space-to-Earth and terrestrial interference levels are expected to be present simultaneously. Rec. ITU-R RS.1884 3 The short-term interference criteria are divided, in equations (2a), (2b) and (2c), among space-to-Earth and terrestrial interference categories. Short-t
23、erm enhanced levels of interference are not likely to occur simultaneously. However, interference from space-to-Earth paths at their long-term levels must be considered when the short-term interference budget is established for terrestrial interfering signal paths, and vice versa. Values for the par
24、ameters Asand asshould be selected to correspond with the relative levels of interference expected from space and terrestrial services. These parameter values are estimated from the allocations, interfering service characteristics, and anticipated usage of the subject frequency band. 2 Determination
25、 of permissible single-entry interference levels Equations (3), (4a) and (4b) accomplish subdivision of the interference budgeted to space-to-Earth signal paths (and terrestrial signal paths, where applicable) in order to establish an appropriate permissible level of interfering signal power from in
26、dividual transmitters (i.e. single-entry interference). i(20) = i (20) / n (3) i(p) = i (p) / yn (i (20) (1 y) (4a) p = p / n (4b) where primed () parameters denote the permissible level of single-entry interfering signal power (i.e. sharing criteria) and: i (20): permissible level of interfering si
27、gnal power (W) for individual space or terrestrial interferers (depending on value of i (20) that is used) to be exceeded for no more than 20% of the time i (20): permissible level of total interfering signal power (W) for space or terrestrial interferers to be exceeded for no more than 20% of the t
28、ime p : percentage of time associated with the short-term interference criteria (equals psor pt in cases where the initial subdivision of interference is made) p : percentage of time calculated for use in specifying short-term single-entry sharing criteria n : equivalent number of space or terrestri
29、al interferers i (p) : permissible level of interfering signal power (W) for individual space or terrestrial interferers (depending on value of i ( p) that is used) to be exceeded for no more than p % of the time i ( p) : permissible level of total interfering signal power (W) for space or terrestri
30、al interferers to be exceeded for no more than p% of the time y : fraction of space or terrestrial interferers producing interference at enhanced levels (0 y 1), (y is analogous to a correlation coefficient and is usually equal to 1/n, i.e. interference entries are mutually uncorrelated). 4 Rec. ITU
31、-R RS.1884 Equations (3), (4a) and (4b) are similar in nature to equations (1a), (1b), (2a), (2b) and (2c). Long-term interference allowances are subdivided on a power basis and short-term interference allowances are subdivided on a percentage of time basis. In equation (4), only some of the interfe
32、rers are assumed to be enhanced to their short-term levels because they are uncorrelated. While these interference entries are enhanced, all other entries are assumed to be at their long-term levels. Annex 2 Example of the application of the methodology 1 Introduction This example is for calculation
33、 of sharing and coordination criteria for meteorological aids systems operating in the bands 400.15 to 406 MHz (referred to as the 403 MHz band throughout) and 1 668.4 to 1 700 MHz (referred to as the 1 680 MHz band throughout). For reference purposes these bands are allocated to the meteorological
34、aids service (MetAids) on a primary basis. 2 Methodology for calculation of MetAids sharing and coordination criteria The interference criteria for MetAids are given in Recommendation ITU-R RS.1263-1 and are presented in Tables 1 and 2. With these values, the sharing and coordination criteria for Me
35、tAids can be determined in accordance with the methodology that was outlined in Annex 1. 2.1 Initial division of interference criteria Annex 1 states that the long-term allowable interference levels for each type of MetAids system listed in Tables 1 and 2 must be subdivided between terrestrial servi
36、ces (it(20) and space-to-Earth paths (is(20). Since long-term interference is present for large percentages of time (the levels from terrestrial services and from space-to-Earth will both be present simultaneously for large percentages of time), the interference is divided on a power basis. Subdivis
37、ion is accomplished using equations (1a) and (1b) of Annex 1. For illustrative purposes within the 403 MHz and 1 680 MHz bands, the power will be subdivided such that 40% is attributed to space-to-Earth paths and 60% will be apportioned to terrestrial paths. The long-term interference criteria for t
38、he terrestrial services and the space-to-Earth paths are presented in Table 3. Rec. ITU-R RS.1884 5 TABLE 1 Interference criteria for radiosonde systems in the MetAids service Parameter Radio direction finding (RDF) radiosonde system1 668.4-1 700 MHz GPS radiosonde system 1 675-1 683 MHz NAVAID with
39、 directional antenna 400.15-406 MHz NAVAID with omnidirectional antenna 400.15-406 MHz System reference bandwidth (kHz) 1 300 150 300 300 Interference signal power (dBW) in the reference bandwidth to be exceeded no more than pLOCK-LOSS(%) of the time 135.3 137.2 141.9 N/A(1)Percentage of time, pLOCK
40、-LOSS (%)(2) 0.02 0.025 0.02 N/A(1)Interference signal power (dBW) in the reference bandwidth to be exceeded no more than pDATA-LOSS (%) of the time 139.4 145.7 149.6 154.4Percentage of time, pDATA-LOSS(%)(2)0.8 0.125 0.2 0.2 Interference signal power (dBW) in the reference bandwidth to be exceeded
41、no more than 20% of the time (2)155.2 152.6 156.1 156.1N/A: Not applicable. (1)Systems with omnidirectional antennas are not vulnerable to losing antenna lock on the signal due to interference or signal fading. (2)This percentage of time shall not be exceeded on a per-flight basis. 6 Rec. ITU-R RS.1
42、884 TABLE 2 Interference criteria for rocketsonde and dropsonde systems in the MetAids service Parameter Airborne dropsonde systems400.15-406 MHz Rocketsonde systems 400.15-406 MHz System reference bandwidth (kHz) 20 3 Interference signal power (dBW) in the reference bandwidth to be exceeded no more
43、 than pLOCK-LOSS(%) of the time N/A(1)116.9 pLOCK-LOSS(%)(2)N/A(1)0.02Interference signal power (dBW) in the reference bandwidth to be exceeded no more than pDATA-LOSS(%) of the time 161.6 122.1 pDATA-LOSS(%)(2)0.060 0.060Interference signal power (dBW) in the reference bandwidth to be exceeded no m
44、ore than 20% of the time 168.9 135.6 N/A: Not applicable. (1)Systems with omnidirectional antennas are not vulnerable to losing antenna lock on the signal due to interference or signal fading. (2)This percentage of time shall not be exceeded on a per-flight basis. TABLE 3 Terrestrial and space-to-Ea
45、rth long-term interference criteria System type as(%) is(20)at(%) it(20)1 680 MHz RDF 40 157.4 dB(W/1.3 MHz) 60 159.2 dB(W/1.3 MHz) GPS radiosonde (1 675-1 683 MHz) 40 154.8 dB(W/150 kHz) 60 156.6 dB(W/150 kHz) 403 MHz NAVAID with directional antenna 40 158.3 dB(W/300 kHz) 60 160.1 dB(W/300 kHz) 403
46、 MHz NAVAID with omnidirectional antenna 40 158.3 dB(W/300 kHz) 60 160.1 dB(W/300 kHz) 403 MHz dropsonde 40 171.1 dB(W/20 kHz) 60 172.9 dB(W/20 kHz) 403 MHz rocketsonde 40 137.8 dB(W/3.0 MHz) 60 136.9 dB(W/3.0 MHz) Rec. ITU-R RS.1884 7 The short-term interference criteria associated with loss of loc
47、k and loss of data must then be calculated using equations (2a) and (2b) of Annex 1. Since short-term interference from the two services is mutually uncorrelated (short-term interference occurs for only very small percentages of time, and the probability of short-term interference from the two servi
48、ces occurring simultaneously is negligible), the short-term criteria are divided on a time basis. Since the probability of long-term levels being present during periods of short-term interference is high, the long-term level must be subtracted from the short-term level in this calculation. For the 4
49、03 MHz and 1 680 MHz bands, the time will be subdivided such that 40% is apportioned to space-to-Earth paths, and 60% will be apportioned to terrestrial paths. The results of the short-term subdivision are presented in Table 4. TABLE 4 Short-term terrestrial and space-to-Earth interference criteria System type ps(%) is(ps)pt(%) it(pt)1 680 MHz RDF Lock loss 0.008 135.3 dB(W/1.3 MHz) 0.012 135.3 dB(W/1.3 MHz) Data loss 0.5 139.5 dB(W/1.3 MHz) 0.75 139.4 dB(W/1.3 MHz) GPS Lock loss 0.01 137.28 dB(W/150 kHz) 0.015 137.25 dB(W/150
