1、 Recommendation ITU-R M.1903(01/2012)Characteristics and protection criteriafor receiving earth stations in the radionavigation-satellite service(space-to-Earth) and receiversin the aeronautical radionavigationservice operating in the band1 559-1 610 MHzM SeriesMobile, radiodetermination, amateurand
2、 related satellite servicesii Rec. ITU-R M.1903 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
3、of frequency range 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 R
4、ight (IPR) ITU-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
5、where the Guidelines 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 prod
6、uction, archival 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
7、SA Space applications 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 ap
8、proved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2012 ITU 2012 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R M.1903 1 RECOMMENDATION ITU-R M.1903 Character
9、istics and protection criteria for receiving earth stations in the radionavigation-satellite service (space-to-Earth) and receivers in the aeronautical radionavigation service1operating in the band 1 559-1 610 MHz (Questions ITU-R 217-2/4 and ITU-R 288/4) (2012) Scope Characteristics and protection
10、criteria for radionavigation-satellite service (RNSS) receiving earth stations and aeronautical radionavigation service (ARNS) receiving stations operating in the band 1 559-1 610 MHz are presented in this Recommendation. This information is intended for performing analyses of radio frequency interf
11、erence impact on RNSS (space-to-Earth) and ARNS receivers operating in the band 1 559-1 610 MHz from radio sources other than in the RNSS. The ITU Radiocommunication Assembly, considering a) that systems and networks in the radionavigation-satellite service (RNSS) provide worldwide accurate informat
12、ion for many positioning, navigation and timing applications, including safety aspects for some frequency bands and under certain circumstances and applications; b) that any properly equipped earth station may receive navigation information from systems and networks in the RNSS on a worldwide basis;
13、 c) that there are various operating and planned systems and networks in the RNSS; d) that there is an essential need to protect systems and networks operating in the ARNS and RNSS in the band 1 559-1 610 MHz; e) that RNSS safety services exist, and that the use of these services will expand in the
14、future; f) that the International Civil Aviation Organization (ICAO) has developed standards for the global navigation satellite system (GNSS), whose elements include systems and networks in the RNSS; g) that the International Maritime Organization (IMO) requires ships to equip with RNSS for navigat
15、ion in narrow waterways and for docking; h) that there are a large number of aeronautical and non-aeronautical RNSS applications that use or plan to use the 1 559-1 610 MHz band; j) that Recommendation ITU-R .1787 provides technical descriptions of systems and networks in the RNSS and technical char
16、acteristics of transmitting space stations operating in the bands 1 164-1 215 MHz, 1 215-1 300 MHz and 1 559-1 610 MHz; 1For the purposes of this Recommendation, references to the aeronautical radionavigation service (ARNS) include only terrestrial transmitters that transmit an RNSS-like signal inte
17、nded for reception by receivers that also receive RNSS signals. As a result, the criteria specified in this Recommendation for RNSS receivers also apply to these ARNS receivers. 2 Rec. ITU-R M.1903 k) that Recommendation ITU-R .1904 provides technical characteristics and protection criteria of recei
18、ving space stations operating in the RNSS (space-to-space) in the bands 1 164-1 215 MHz, 1 215-1 300 MHz and 1 559-1 610 MHz; l) that Recommendation ITU-R M.1901 provides guidance on this and other ITU-R Recommendations related to systems and networks in the RNSS operating in the frequency bands 1 1
19、64-1 215 MHz, 1 215-1 300 MHz, 1 559-1 610 MHz, 5 000-5 010 MHz and 5 010-5 030 MHz, recognizing a) that the band 1 559-1 610 MHz is allocated on a primary basis to the RNSS (space-to-Earth) (space-to-space) and ARNS in all three Regions; b) that there are a number of receivers of RNSS signals used
20、in safety service applications that process these signals in different ways, as described in Annex 2; c) that there are a number of different existing and planned augmentations of systems and networks in the RNSS which support safety services; d) that Recommendation ITU-R M.1343 defines the essentia
21、l technical requirements of mobile earth stations (MESs) for global non-GSO MSS systems in the bands 1-3 GHz; e) that No. 5.362B provides that the band 1 559-1 610 MHz is also allocated to the fixed service on a primary basis until 1 January 2010 in a number of countries; that the fixed service may
22、continue to operate on a secondary basis in these countries from 1 January 2010 to 1 January 2015, after which the allocation is no longer valid; that in a number of other countries the band 1 559-1 610 MHz is allocated to the fixed service on a secondary basis until 1 January 2015, after which time
23、 the allocation is no longer valid; and that administrations of all countries listed in No. 5.326B are urged to take all practicable steps to protect the RNSS and the ARNS and not authorize new frequency assignments to fixed-service systems in the band; f) that No. 5.362C provides that the band 1 55
24、9-1 610 MHz is also allocated to the fixed service on a secondary basis in a number of countries until 1 January 2015, after which the allocation is no longer valid; and that administrations of all countries listed in No. 5.326C are urged to take all practicable steps to protect the RNSS and not aut
25、horize new frequency assignments to fixed-service systems in the band, recommends 1 that the characteristics and protection criteria of receiving earth stations given in Annex 2 should be used in performing analyses of the interference impact on ARNS and RNSS (space-to-Earth) receivers operating in
26、the band 1 559-1 610 MHz from radio sources other than in the RNSS; 2 that a safety margin, as discussed in Annex 1, should be applied for the protection of the safety aspects and applications of the RNSS and ARNS, when performing interference analyses; 3 that the following Notes should be considere
27、d as part of this Recommendation. NOTE 1 This Recommendation is not intended to be used to form the basis for future modifications to maximum unwanted emission levels for the band 1 559-1 610 MHz that are stated in the Annexes to Recommendations ITU-R M.1343-1 and ITU-R M.1480 for MSS MESs, and ITU-
28、R SM.1757 for UWB. The maximum unwanted emission levels for the band 1 559-1 610 MHz stated in Recommendations ITU-R M.1343-1 and ITU-R M.1480 have been developed pursuant to a specific interference scenario, and are not intended to be applied to any service other than MSS MESs operating in the 1-3
29、GHz range without further study. Levels given in Recommendation ITU-R SM.1757 are specific to ultra-wideband technology. NOTE 2 The 6 dB aeronautical radionavigation safety margin, as discussed in 3 of Annex 1, was developed for a specific aeronautical radionavigation application of the RNSS and ARN
30、S in the Rec. ITU-R M.1903 3 band 1 559-1 610 MHz, and was not intended to be applied to non-aeronautical applications. The level of the safety margin, if any, to be applied to non-aeronautical safety applications of RNSS is to be established on the basis of further study. Annex 1 Margin for safety
31、applications in the RNSS 1 Introduction There is a long history within ITU and ICAO of reserving a portion of the interference link budget for a margin in order to ensure that the safety aspects of the radionavigation service are protected. These margin values typically lie in the range of 6 to 10 d
32、B, or more. Furthermore, there is ample precedent for a safety margin for radionavigation safety applications in ITU-R, for example: “Regardless of the original intentions of radio spectrum planners, there can be no doubt that the pressure on the radio spectrum for additional allocations to the vari
33、ous radio communication services can result in aeronautical protection criteria being effectively regarded as non-aeronautical sharing criteria. As a consequence, a safety service must take considerable precautions to ensure that any radio service sharing the same radio band is constrained sufficien
34、tly to leave an adequate margin under all likely circumstances so that the aggregate harmful interference never exceeds the required protection criteria.”2Also, Recommendation ITU-R M.1318-1 contains, in its Annex, a model for the evaluation of interference to RNSS receivers from radio sources other
35、 than in the RNSS. That model includes the use of a factor called “protection margin (dB)”. Its description states that it is used “to ensure protection as provided by RR No. 4.10.” 2 Purpose of safety margin A safety margin (which may also be called a public safety factor), is critical for safety-o
36、f-life applications in order to account for risk of loss of life due to radio-frequency interference that is real but not quantifiable. To support safety-of-life applications, all interference sources must be accounted for. 3 Aeronautical radionavigation applications of safety margin 3.1 Aeronautica
37、l radionavigation safety margin background The utilization of safety margins in navigation systems is well established. ICAO specifies a safety margin for the microwave landing system (MLS) of 6 dB (Annex 10 to ICAO Convention: International Standards and Recommended practices Aeronautical Telecommu
38、nications, Vol. 1 Radio Navigation Aids (Attachment G, Table G-2). The instrument landing system (ILS) applies a safety margin of 8 dB (see Recommendation ITU-R SM.1009-1, Appendix 3 to Annex 2). In each case the margin is defined with respect to the navigation system carrier power. That is, to test
39、 system performance for these systems, the desired signal power is reduced from the nominal level by the safety margin, and then tested to determine whether the system provides the 2This text appeared in Annex 5 of Recommendation ITU-R M.1477 (Geneva, 2000), among other places. 4 Rec. ITU-R M.1903 r
40、equired performance in the presence of interference. In other words, the manufacturer must design the equipment to handle the highest anticipated interference level while receiving a desired signal level lower (by the safety margin) than would be otherwise received. With GNSS3this approach is not po
41、ssible, because reducing the carrier power by 6 dB or more below the designed power could result in satellites being dropped in the tracking algorithm of the receiver. This is because the received GNSS satellite power is relatively limited, and thus GNSS receivers operate over a small dynamic range.
42、 For GNSS receivers, the principal received signal quality measure is the C/N0,EFFratio, the ratio of the recovered carrier power, C, to the effective noise + interference power spectral density, N0,EFF= N0+ I0. GNSS receivers must be capable of operating near the minimum C/N0,EFFvalue, a region whe
43、re important performance parameters, such as detected word error rate or carrier phase error, rise rapidly for small reductions in C/N0,EFFdue, for example, to interference. 3.2 Safety margin for the GNSS in the band 1 559-1 610 MHz As with the MLS and ILS, the approach for the GNSS is to define a l
44、evel of non-aeronautical radio-frequency interference4(RFI) that the receiver must be able to accept and still meet performance specifications. For the GNSS, the receiver RFI test limit (i.e. the design threshold) exceeds the maximum allowable environmental aggregate interference level by a safety m
45、argin. Specifically, if the aggregate continuous interference test limit for GNSS is Jagg,max(dBW) and a safety margin, M (dB), is used, then the maximum safe environmental aggregate continuous RFI, Jsafe,max(dBW) is: Jsafe,max= Jagg,max M For the GNSS in the 1 559-1 610 MHz band, the necessary safe
46、ty margin, M (dB), is 6 dB. A safety margin of 5.6 dB was used in the development of the 70 dB(W/MHz) emission limit adopted in Recommendation ITU-R M.1343-1. However, for general application this margin is adjusted slightly to 6 dB, which brings it into the range of safety service margins which hav
47、e been adopted by ITU-R for other safety applications, as indicated in 3.1 above. For example, a Category I precision approach SBAS Type 1 air navigation receiver (see Table 2 of Annex 2) operating in the 1 575.42 12 MHz band is designed and tested to withstand a wideband aggregate interference thre
48、shold level of 140.5 dB(W/MHz) in the signal tracking mode. Applying the 6 dB safety margin, as indicated in the equation above, to the aggregate threshold results in the safe level of allowable received interference of 146.5 dB(W/MHz). An aeronautical safety margin of at least 6 dB is required to p
49、rotect the GNSS safety applications. Additional margins may be required, depending on: the effects of the statistics on all parameters used in interference analyses unless the worst-case conditions are assumed; and RFI sources that are not specifically included in the interference analysis but that may have a potential to contribute to the interference of GNSS. 3GNSS refers to Global Navigation Satellite System, a set of RNSS systems providing aeronautical radionavigation satellite signals as recognized by ICAO. 4Non-aeronautical interference refers to interference f
