1、 Rec. ITU-R M.1582 1 RECOMMENDATION ITU-R M.1582 Method for determining coordination distances*, in the 5 GHz band, between the international standard microwave landing system stations operating in the aeronautical radionavigation service and stations of the radionavigation-satellite service (Earth-
2、to-space) (2002) The ITU Radiocommunication Assembly, considering a) that the band 5 000-5 250 MHz is allocated to the aeronautical radionavigation service on a primary basis; b) that the band 5 030-5 150 MHz is intended for the operation of the international standard microwave landing system (MLS)
3、for precision approach and landing; the requirements for this system shall take precedence over other uses of this band in accordance with No. 5.444 of the Radio Regulations (RR); c) that the World Radiocommunication Conference (Istanbul, 2000) (WRC-2000) added a co-primary allocation for the radion
4、avigation-satellite service (RNSS) (Earth-to-space) in the 5 000-5 010 MHz band; d) that emissions from RNSS stations may cause interference to aeronautical MLS receivers during approach and landing; e) that the MLS can be well protected through the implementation of an adequate separation distance
5、between RNSS (Earth-to-space) transmitters and MLS receivers, and other mitigation techniques; f) that RR No. 4.10 provides recognition that special measures are required for the protection of radionavigation and safety services; g) that WRC-2000 has adopted Resolution 603 (WRC-2000) to conduct tech
6、nical, operational and regulatory studies to ensure that stations of the RNSS (Earth-to-space) do not cause harmful interference to the operation of the international standard MLS, recognizing a) that the methods contained herein are based on current specifications for international standard MLS rec
7、eiving equipment, recommends 1 that the method for determining coordination distances between international standard MLS stations operating in the band 5 030-5 150 MHz and RNSS Earth-to-space stations in the 5 000-5 010 MHz band, described in Annex 1, should be used. _ *Within this Recommendation, a
8、 coordination distance must be understood to be the minimum required separation distance beyond which Earth-to-space stations of the RNSS will not cause harmful interference into MLS receivers. However, these protection distances may be decreased on a case-by-case basis, as the result of an agreemen
9、t between the administrations concerned. 2 Rec. ITU-R M.1582 ANNEX 1 Method for determining coordination distances This Annex sets forth a method for determining coordination distances relative to current and planned MLS stations that may be used to enable implementation of stations of the RNSS (Ear
10、th-to-space). Coordination will not be required between RNSS (Earth-to-space) and MLS transmitter sites at the same altitude and which are separated by more than 450 km. Beyond 450 km, MLS airborne stations are expected to be sufficiently beyond the radio line-of-sight of the RNSS (Earth-to-space) e
11、arth station to protect the MLS. This coordination distance is subject to further review. For separation distances provisionally less than 450 km, the need for coordination is identified and dependent on the mitigation factors a) to e), as identified below. Range separation triggers for coordination
12、 may be defined as a result of internationally standardized specifications for MLS out-of-band and inband interference susceptibility criteria. For the purpose of this method, the terms out-of-band and inband are relative to the MLS band 5 030-5 150 MHz (see also item e) below). These triggers may b
13、e denoted Roobfor the out-of-band range separation trigger, and Rinfor the inband range separation trigger, as defined below: 4310)10775.4()km()20/)91(621+=+PoobR (1) where P1is the total e.i.r.p. (dBW) of RNSS (Earth-to-space) earth station in the band 5 000-5 010 MHz, based on free space propagati
14、on from the RNSS station to an MLS equipped aircraft within the MLS service volume. 4310)10775.4()km()20/)160(622+=+PinR (2) where P2is the peak RNSS (Earth-to-space) earth station e.i.r.p. density (dB(W/150 kHz) in the band 5 030-5 150 MHz, based on free space propagation from the RNSS station to a
15、n MLS equipped aircraft within the MLS service volume, and an MLS inband interference threshold of 160 dBW. When performing this initial calculation care must be taken to ensure that no fixed-satellite service earth stations, which have been coordinated using Recommendation ITU-R S.1342 or other RNS
16、S (Earth-to-space) earth stations, lie within the coordination distance of the MLS. If such an earth station exists, then the potential aggregate effect must be taken into account. The MLS service volume is 43 km in radius with the MLS transmitter at the centre. If both Rooband Rinare less than the
17、planned range based on the candidate RNSS (Earth-to-space) earth station location and current or planned MLS transmitter location(s), MLS operations will be unaffected and further analysis and coordination is not required. If either Roobor Rinexceeds the planned range based on the candidate RNSS (Ea
18、rth-to-space) earth station location and current or planned MLS Rec. ITU-R M.1582 3 transmitter location(s), further analysis and coordination is required. Some factors identified below may be considered in a more detailed analysis: a) site-specific signal attenuation factors such as terrain blockin
19、g and radio horizon; b) increased filtering of the transmitted RNSS earth station uplink signal; c) antenna orientation and directive gain characteristics of RNSS (Earth-to-space) earth station transmit antenna; d) alternative locations for the RNSS (Earth-to-space) earth station; e) in regions wher
20、e current and projected MLS deployments are expected to be limited, consideration may optionally be given to the additional frequency separation afforded by MLS operation in the upper channels of the MLS channel plan extending from 5 030 MHz to 5 150 MHz. This option should be at the discretion of t
21、he affected national authorities. Items a) through d) may affect the power level of RNSS (Earth-to-space) earth station emissions in the direction of MLS service volumes. Item e) may affect the operating frequency(ies) of MLS. This, in turn, may reduce the level of relevant RNSS spurious emissions i
22、n the 2.4 MHz band centred on the MLS frequency assignment, which affects Rin. Additional factors may be considered on an individual basis; however, the need to maintain the reliability and integrity requirements of MLS, consistent with the safety of flight service it provides, needs to be addressed.
