1、 Rep. ITU-R M.2118 1 REPORT ITU-R M.2118 Compatibility between proposed systems in the aeronautical mobile service*and the existing fixed-satellite service in the 5 091-5 250 MHz band (2007) Introduction This Report is related to Agenda items 1.5 and 1.6 of WRC-07. It proposes a methodology based on
2、 Appendix 8 of the Radio Regulations and other ITU-R documents and Recommendations, for the compatibility analyses between possible new systems in the aeronautical mobile service and non-GSO MSS feeder links in the fixed-satellite service in the 5 091-5 250 MHz band. 1 Structure of the Report This R
3、eport sets forth a general methodology for computing the aggregate Ts/Tsseen by the FSS from new systems, and the T/T levels seen by any one of the new systems due to the other new systems. The new systems include AM(R)S, systems of Aeronautical Mobile Telemetry (AMT) limited to flight testing, and
4、aeronautical security1. The methodology is then applied, in detail, in each of three annexes. Annex 1 explores sharing with AM(R)S. Annex 2 discusses sharing by systems of AMT. Annex 3 describes a proposed aviation security system and the resulting sharing scenarios. In addition, the impact of FSS o
5、n these new AMS systems is also considered. 2 Methodology The methodology is based on Appendix 8 of the Radio Regulations (RR), including Document 8B/195, and Recommendations cited above. It is based on a computation of an aggregate Ts/Ts, where Tsis the noise temperature of the satellite (that is,
6、Ts= Tspace station), performed using equation (1): ()()CklggpTTTNnn nuenteSSSnnn=1211(1) where C is the proposed criterion for sharing assessment. *Limited to aeronautical mobile telemetry for aircraft flight testing (referred to as AMT) and AMS for aeronautical security, and AM(R)S. 1Terminology: A
7、n aeronautical mobile service that supports aeronautical security transmissions ensure confidential and secure radiocommunications between aircraft and ground intended for systems used in response to interruption of aircraft operations that have not been permitted by the appropriate authorities. 2 R
8、ep. ITU-R M.2118 The parameters are defined as follows (see Appendix 8): Ts: receiving system noise temperature of the receiver channel under consideration of the space station, referred to the output of the receiving antenna for that channel of the space station (K) Ts: apparent increase in the rec
9、eiving system noise temperature of the satellite S, caused by an aggregate interfering emission, referred to the output of the receiving antenna of this satellite (K) g2(): receiving antenna gain of satellite S in the direction (numerical power ratio) g1n(t ): transmitting antenna gain of the earth
10、station number n (AM(R)S or AMS) in the direction of satellite S (numerical power ratio) pen: maximum power density per Hz delivered to the antenna of the transmitting earth station number n (averaged over the worst 4 kHz band) (W/Hz) e:direction, from satellite S, of the transmitting earth station
11、number n tn: direction, from the earth station number n, of the satellite S k: Boltzmanns constant (1.38 1023J/K) lun: free-space transmission loss on the uplink (numerical power ratio), evaluated from the earth station number n, to satellite S N: number of earth station (AM(R)S for AI 1.6 and AMS f
12、or AI 1.5) n: index of the earth station. In order to perform computations using equation (1), a scenario for the location of the earth stations (AM(R)S or AMS) is needed as well as a worst-case assumption on the maximum number of earth stations operating at the same time in the satellite receiver b
13、andwidth and visibility. The methodology consists in computing equation (1) for each time step of the above-defined scenario. 3 Proposed criteria for sharing assessment In the studies of this document, the following criteria2are considered: In the band 5 091-5 150 MHz (aggregate Ts/Tsfor all other p
14、rimary services of 6%): A maximum Ts/Tsof 3% for the ARNS; A maximum Ts/Tsof 2% for the AM(R)S or the AMS limited to aeronautical security applications; A maximum Ts/Tsof 1% for the AMS limited to AMT. In the band 5 150-5 250 MHz (aggregate Ts/Tsof 6%): A maximum Ts/Tsof 3% for the MS (RLAN); 2In co
15、mmon with other applications using bands allocated to the FSS, in keeping with Recommendation ITU-R S.1432, WP 4A considers it appropriate for MSS feeder up-links to be designed to allow an aggregate of 6% of the total noise to interference from other primary services in the band 5 091-5 150 MHz. Th
16、us on the assumption that there is unlikely to be significant MLS development in this band before 2018, it would seem reasonable to allow 3% of the MSS feeder up-link noise budget to interference from the aeronautical radionavigation service, and the other 3% for all other services. Rep. ITU-R M.211
17、8 3 A maximum Ts/Tsof 3% for other services: A maximum Ts/Tsof 1% for the AMS limited to AMT; A maximum Ts/Tsof 2% for other services (not precise). 4 List of characteristics used in the compatibility analyses For an FSS system considered in the analyses that follow, the following criteria have been
18、 used: TABLE 1 Parameter values used in satellite interference calculations Parameter HIBLEO-4 FL Satellite orbit altitude h (km) 1 414 Satellite receiver noise temperature T (K) 550 Interference threshold H (dBm) in 1.23 MHz (Ts/Ts= 3%) 125.5 Interference threshold H (dBm) in 1.23 MHz (Ts/Ts= 2%) 1
19、27.3 Interference threshold H (dBm) in 1.23 MHz (Ts/Ts= 1%) 130.3 Polarization discrimination Lp(dB) 1 Feed loss Lfeed(dB) 2.9 Satellite receiver bandwidth B (MHz) 1.23 Satellite receive antenna gain (dBi) 4 Some of the parameters that have been used for characterization of AMS systems in the analys
20、es: N: maximum expected AMS operating at the same time in the satellite receiver bandwidth. Worst-case scenario AMS stations location versus time. The antenna gain patterns (ground and airborne). The maximum power density per Hz delivered to the antenna of the transmitting earth station (averaged ov
21、er the worst 4 kHz band) (W/Hz) (Pe). AMS typical emitter filter. AMS typical modulation. Specific values for these parameters are given in the Annexes of this Report. 4 Rep. ITU-R M.2118 5 Conclusion 5.1 Impact into FSS conclusion Analyses indicate, for the systems described in the annexes and visi
22、ble within an FSS satellite antenna footprint, that interference to the FSS from the proposed AMT, AM(R)S, and a future aeronautical security system will represent a Ts/Tsof less than 2.7% (criterion 3%) accounted by typically: 0.7% (criterion 1%) for AMT in the band 5 091-5 250 MHz; less than 2% (c
23、riterion threshold for AM(R)S plus AMS for security) in the band 5 091-5 150 MHz for: either AM(R)S; or AMS for aeronautical security. In the band 5 091-5 150 MHz, in order not to exceed a Ts/Tsof 2% allowable for AM(R)S plus AMS for security, AM(R)S and AMS for security cannot operate co-frequency
24、at the same time (within the field of view of a single non-GSO satellite). The practical means for operating in a time sharing mode would require a very complex coordination procedure. Therefore it is proposed that AM(R)S and AMS for security operate in a non co-frequency basis. With respect to the
25、band 5 091-5 250 MHz, it should be noted that this band is already used by existing allocations and that the addition of new allocations, such as AMS and AM(R)S, will increase interference to the FSS feeder links unless significant steps are taken. These steps would need to include some kind of regu
26、latory arrangement, where necessary, that would ensure the protection of the FSS, utilizing the 5 091-5 250 MHz band, from unacceptable interference. 5.2 Impact from FSS conclusion 5.2.1 Impact into AMS for telemetry limited to flight testing The compatibility between the FSS ground transmitter and
27、the AMS for telemetry limited to flight testing ground receiver can be handled at AMS for telemetry application level by ensuring sufficient distance separation between these stations. Due to the limited number of these ground stations this should be manageable. 5.2.2 Impact into AM(R)S The compatib
28、ility between the FSS ground transmitter and the AM(R)S ground receiver located at airports can be handled by ensuring sufficient distance separation between these stations and/or appropriate frequency separation. Due to the limited number of FSS ground stations and the limited location of AM(R)S gr
29、ound stations at airports this should be manageable. 5.2.3 Impact into AMS for security The compatibility between the FSS ground transmitter and the AMS for security ground receiver can be handled at AMS for security application level by ensuring sufficient distance separation between these stations
30、 and/or appropriate frequency separation. Due to the limited number of these ground stations this should be manageable. The compatibility between the FSS ground transmitter and the AMS for security airborne receiver can be handled at AMS for security application level as any interference suffered wo
31、uld not be frequent. Rep. ITU-R M.2118 5 Annex 1 Aeronautical mobile (R) service 1 Introduction 1.1 The very high frequency (VHF) band 117.975-137 MHz is heavily utilized in the for air-ground communications associated with air traffic services and aeronautical operational control supporting safety
32、and regularity of flight and operating in the aeronautical mobile (route) service (AM(R)S). In fact, use of the band is such that in some regions it is very difficult to find channels to meet current requirements. While regional efforts are underway to extend the capacity through measures such as ch
33、annel splitting and/or functional reassignments, with the expected growth in air service, together with increasing desires for more data to the flight crews, the spectrum shortage issue will become even more challenging. This need was recognized at WRC-03 as evidenced by Agenda item 1.6 for WRC-07.
34、In order to determine requirements for new AM(R)S spectrum, a number of aviation studies were completed. 1.2 Results of the studies provide guidance as to future AM(R)S requirements. In particular more spectrum is needed to support: surface applications; air-ground/air-air voice and data link applic
35、ations; advanced surveillance/navigation applications; unmanned aerial vehicle (UAV) control. The 5 091-5 150 MHz band has been identified to satisfy the requirements of the first category-surface applications. 1.3 Studies have turned up a number of AM(R)S applications for the airport surface. These
36、 range from uploads of routing and electronic flight bag information, to de-icing, and surface mapping to preclude runway incursion and aid in obstacle avoidance. In general those applications share the characteristics of short-range (e.g. 3 km) and high bandwidth per airport. Limitation to ground t
37、ransmission, and geographic separation of airports would likely ease airport-to-airport channel reuse. 1.4 To accommodate future growth in surface applications, portions of the 5 GHz band have been selected for evaluation as a potential spectrum location for an airport radio local area network (RLAN
38、). Initial studies have indicated that the 5 GHz band is well suited to the type of applications envisioned, and work is being accomplished to determine if IEEE 802.xx technologies utilized in adjacent bands (i.e. above 5 150 MHz) for commercial, unlicensed terrestrial RLANs can be leveraged3. 3This
39、 proposed AM(R)S application will be implemented only at airports. 6 Rep. ITU-R M.2118 2 System characteristics 2.1 Assumed aviation system 2.1.1 In order to address the mix of aviation applications intended for the airport surface, development of an airport safety-rated RLAN is envisioned for the 5
40、 091-5 150 MHz sub-band. One candidate architecture is the airport network and location equipment (ANLE) system. ANLE is visualized as a high-integrity, safety-rated wireless RLAN for use at airports, combined with an interconnected grid of multilateration sensors. Simple transmitters would be added
41、 to surface-moving vehicles, allowing for the development of a high-fidelity, complete picture of the airport surface environment. In order to speed development and reduce the cost of the ANLE, the system would be based on existing Institute of Electrical and Electronics Engineers (IEEE) “802-Family
42、” standards4. 2.1.2 While there are several protocols in the IEEE 802 family standards, analysis has focused on two candidates for the ANLE application: 802.11a and 802.16e: 802.11a currently operates in the 5 GHz unlicensed band using an orthogonal frequency division multiplexing (OFDM) modulation
43、scheme. It operates using 20 MHz wide channels. 802.16e is designed to support non-line-of-sight (NLOS) communications in the 2-11 GHz band. Though below 6 GHz the standard allows various channel bandwidths, a 20 MHz channel has been defined to be compatible with the 802.11a standard, and is the cha
44、nnel bandwidth assumed for this analysis. One desirable feature of 802.16e is that it has been designed to allow for networking between users with relative speeds of up to 150 km/h suitable for taxing aircraft. 2.1.3 Because of the “mobility” capabilities built into IEEE 802.16e, it is expected that
45、 it will prove to be the most compliant with aviation requirements. As a result, the remainder of Annex 1 will focus on that protocol. 3 Airport LAN characteristics 3.1 As noted above, a key parameter of the sharing study is ANLE transmitter power. Providing connectivity, with conservative margins t
46、o account for fading effects, over the assumed 3 km maximum range drives required transmitter power. ANLE transmitter and receiver antenna gain, ANLE receiver sensitivity, and path loss over the 3 km range in turn drive connectivity between the ANLE transmitter and the ANLE receiver. 3.2 The ANLE tr
47、ansmitter antenna gain versus elevation angle pattern considered in the analysis is adopted from International Telecommunication Union (ITU) Radiocommunication Sector, Recommendation ITU-R F.1336-15and is shown in Fig. 1. For this initial analysis, the radiation pattern was assumed to be omnidirecti
48、onal in the horizontal plane. It must be noted that in practice, many if not all installed ANLE antennas are likely to have sectoral rather than omnidirectional horizontal-plane patterns. Sectoral antennas would allow ANLE 4While the system would be based on the IEEE standards, it is expected that s
49、ystem elements would be tailored for the aviation application. Such tailoring might include bandpass filtering to facilitate sharing with adjacent band MLS, improved receiver sensitivities, and sectorized antennas. 5Reference radiation patterns of omnidirectional, sectoral and other antennas in point-to-multipoint systems for use in sharing studies in the frequency range from 1 GHz to above 70 GHz, Recommendation ITU-R F.1336-1 (1997-2000 version). Rep. ITU-R M.2118 7 transmitters to operate at l
