1、 Report ITU-R M.2168-1(11/2010)Compatibility between a proposed new aeronautical mobile (R) service (AM(R)S) system and both radionavigation-satellite service (RNSS) operating in the5 000-5 010 MHz band and radio astronomy in the adjacent band 4 990-5 000 MHzM SeriesMobile, radiodetermination, amate
2、urand related satellite servicesii Rep. ITU-R M.2168-1 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
3、 limit 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 Pro
4、perty Right (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/pate
5、nts/en 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 Reports (Also available online at http:/www.itu.int/publ/R-REP/en) Series Title BO Satellite delivery BR Recording for produ
6、ction, 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 S
7、A Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management Note: This ITU-R Report was approved in English by the Study Group under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 20
8、11 ITU 2011 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R M.2168-1 1 REPORT ITU-R M.2168-1 Compatibility between a proposed new aeronautical mobile (R) service (AM(R)S) system and both radionavigation-satell
9、ite service (RNSS) operating in the 5 000-5 010 MHz band and radio astronomy in the adjacent band 4 990-5 000 MHz*(2009-2010) TABLE OF CONTENTS Page Objective 2 1 Introduction 2 2 System characteristics 2 2.1 AM(R)S system 2 2.2 RNSS systems . 3 2.3 Radio astronomy . 4 3 Analysis methodology 4 3.1 A
10、nalysis parameters 4 3.2 Interference to AM(R)S 4 3.3 Interference to RNSS 5 3.4 Interference to radio astronomy 5 4 Compatibility study results and discussion 5 4.1 RNSS 5 4.2 Radio astronomy results . 8 5 Conclusions 9 Appendix A IEEE 802.16e 9 *This Report should be brought to the attention of Ra
11、diocommunication Study Groups 4 and 7. 2 Rep. ITU-R M.2168-1 Objective This Report addresses the feasibility of an allocation for AM(R)S for surface applications at airports with particular emphasis on technical and operational issues relating to the protection of RNSS in the band 5 000 and 5 010 MH
12、z and of the radio astronomy service in the band 4 990-5 000 MHz from AM(R)S. 1 Introduction 1.1 Studies within ITU-R have identified a number of AM(R)S applications for airport surfaces. These range from uploads of routing and electronic flight bag information, to scheduling de-icing facilities, an
13、d surface mapping to preclude runway incursion and aid in obstacle avoidance. In general those applications share the characteristics of short-range (a few kilometres maximum) and high bandwidth per airport. Limitation to ground transmission and the geographic separation of airports will likely faci
14、litate airport-to-airport channel reuse. 1.2 To accommodate future growth in surface applications, the 5 000-5 010 MHz band has been selected for evaluation as potential additional spectrum for the airport surface local area network (LAN) currently being developed for operation in the 5 091-5 150 MH
15、z band. The 5 000-5 010 MHz band currently has aeronautical radionavigation service (ARNS), aeronautical mobile-satellite (R) service (AMS(R)S, reference Radio Regulations No. 5.367), and radionavigation-satellite service (RNSS) Earth-to-space (E-s) allocations. Taking into account that a final dete
16、rmination on compatibility cannot be made until both the AM(R)S and RNSS systems are fully defined, this paper presents the results of initial considerations on compatibility between a proposed new AM(R)S system and RNSS (E-s) systems operating simultaneously in the 5 000-5 010 MHz band. In addition
17、, considerations on compatibility of the proposed new AM(R)S system with the radio astronomy service (RAS) operating in the adjacent 4 990-5 000 MHz band are also examined. 2 System characteristics 2.1 AM(R)S system 2.1.1 In order to address the mix of aviation applications intended for the airport
18、surface, an airport safety service LAN is being developed for operation in the 5 091-5 150 MHz band. Based on projected spectrum requirements for such a system, its operation in the 5 000-5 010 MHz band is also under consideration. One candidate architecture is the airport network and location equip
19、ment (ANLE) system. ANLE is visualized as a high-integrity, safety communications, wireless LAN for the airport area, combined with an interconnected grid of multilateration sensors. Simple transmitters would be added to surface-moving vehicles, allowing for the development of a high-fidelity, compl
20、ete 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 series” standards1. As noted in Report ITU-R M.2118, because of the “mobility” capabiliti
21、es built into IEEE 802.16e, it is expected that it will prove to be compliant with aviation requirements. As a result, the remainder of this analysis will reference that protocol. Example AM(R)S parameters are shown in Table 1. Due to the signal modulation utilized, it is expected that the AM(R)S si
22、gnal will look noise-like to RNSS and RAS receivers. 1While the system would be based on the IEEE 802 series standards, it is expected that system elements would be tailored for the aviation application. Such tailoring might include bandpass filtering to facilitate sharing with adjacent band MLS, im
23、proved receiver sensitivities, and sectorized antennas. Rep. ITU-R M.2168-1 3 TABLE 1 Example AM(R)S based on IEEE 802.16 e parameters Parameter ANLE Operational bandwidth (MHz) 20(1)Receiver sensitivity Rxs(dBm) 83.4(2)Base station antenna gain Gt(dBi) 8.0 Subscriber unit antenna gain Gr(dBi) 6.0 A
24、ssumed link margin (dB) 11 Path loss exponent 2.3 Free-space characteristic distance d0(m) 462 Transmitter power required Pt 32.2 dBm(3)(1) Though this is larger than the band being examined (5 000-5 010 MHz), it results in the worst-case (i.e. highest) transmitter power requirements for the AM(R)S
25、system. Since the maximum sub-carrier power and spacing remains constant (see Appendix A), the total power transmitted in the 5 000-5 010 MHz band would be 3 dB less.(2) This sensitivity is for a receiver using all the sub-carriers within a 20 MHz bandwidth. Receiver sensitivity varies versus sub-ca
26、rrier/channel bandwidth, so a receiver using only all the sub-carriers in the 5 000-5 010 MHz band would be 3 dB more sensitive.(3) This is the power required to close the link to users at 3 km assuming worst-case receiver sensitivity. The scalable OFDMA implementation and power control (as describe
27、d in the IEEE 802.16e standard) will reduce the power based on actual transmitted bandwidth (by a factor of 10 log (No. used subcarriers/total subcarriers), and based on actual measured signal-to-noise (such that the minimum signal-to-noise is maintained for the selected modulation).2.1.2 Regarding
28、the time waveform of the AM(R)S signal, for a system based on IEEE 802.16e standards it is envisioned that there really will be no “basic” message duration, rather the parameters are selectable from a “menu” of options. This flexibility of the AM(R)S system is anticipated to exist both in channel ba
29、ndwidth (i.e. the spectral domain), and message frame duration (i.e. the time domain). In general each frame consists of a forward link (FL; base-to-subscriber) and a reverse link (RL; subscriber-to-base) portion shared on a time division duplex manner where FL and RL transmissions occur on the same
30、 frequency channel, but in different (time) portions of the frame. A typical division might be 2/3 FL, and 1/3 RL. It is also envisioned that there will be a brief guard time between all FL and RL frames. Depending on the channel bandwidth during a message frame, a number of message symbols are tran
31、smitted. Those symbols are distributed in frequency across the sub-carriers for the selected channel bandwidth. Further details on IEEE 802.16e are contained in Appendix A. 2.2 RNSS systems Details of the RNSS parameters used for this Report are provided below. The T/T analysis presented in 4 provid
32、es compatibility analysis results for all RNSS systems in the band 5 000-5 010 MHz. The resulting maximum allowable aggregate interference using the T/T criterion is calculated. 2.2.1 The 5 000-5 010 MHz band is allocated to RNSS (E-s), and as such would be used for RNSS feeder links. System paramet
33、ers used for the analysis are shown in Table 2. 4 Rep. ITU-R M.2168-1 2.2.2 The aggregate interference levels to RNSS systems operating in the band 5 000-5 010 MHz from all radio sources of primary services in the band other than in the RNSS should not exceed 6% (i.e. I/N of 12.2 dB) of the worst-ca
34、se RNSS receiver system noise. Considering that ARNS and AMS(R)S already exist in this frequency band, 2% of the RNSS receiver system noise due to the aggregate AM(R)S interference should be applied. TABLE 2 RNSS parameters for compatibility analysis Parameter Galileo GPS QZSS Coverage global global
35、 Regional Noise temperature (K) 580 590 400 Bandwidth (MHz) 10 1.1 0.4/channel Feeder loss (LFeed, dB) 1 1 0(1)Maximum RNSS antenna gain (Gr, dBi) 12.8 13.6 16.8(1)Minimum satellite altitude (km) 23 222 20 200 31 600 (1)For QZSS, feeder loss is included in the antenna gain value. 2.3 Radio astronomy
36、 Details, parameters and approach for compatibility analyses with RAS are contained in relevant ITU-R RA-series Recommendations, in particular Recommendation ITU-R RA.769. Of particular note is that the RAS has a long history of compatible operation with adjacent band mobile applications, as reflect
37、ed by the large number of frequency bands where such operations occur. Of particular note the 4 990-5 000 MHz and the adjacent 4 800-4 990 MHz band are both currently in use by some administrations, on a primary basis to the mobile (except aeronautical mobile) service. This is important because whil
38、e the service being considered in this Report is aeronautical mobile (i.e. AM(R)S), restriction of that service to surface application at airports results in compatibility conditions similar to those for the “mobile (except for aeronautical mobile)” service. 3 Analysis methodology 3.1 Analysis param
39、eters For the analysis, the RNSS was assumed to have the characteristics of Table 2 and the resultant limits on the AM(R)S were derived. For Earth-to-space paths standard free-space propagation was assumed. Total path loss is then computed as the propagation path loss plus any polarization and cable
40、 losses. 3.2 Interference to AM(R)S While sharing studies must take into account both directions, the assessment of RNSS-to-AM(R)S compatibility was relatively simple. In the 5 000-5 010 MHz band the RNSS transmissions come from a high-gain, well-focused dish antenna, generally geographically separa
41、ted from major airports, so the RNSS transmissions would not cause unacceptable levels of interference to a ground-based airport AM(R)S receiver. In the case that an RNSS feeder-link earth station needs to be in close proximity to a major airport, it is expected that local coordination up to and inc
42、luding Rep. ITU-R M.2168-1 5 not using specific AM(R)S channels at that airport can be employed to solve any remaining issues. While reducing the number of channels will reduce maximum useable AM(R)S data rates and may reduce overall efficiency at those airports, those excluded AM(R)S channels could
43、 potentially be used at other airports. 3.3 Interference to RNSS Using the RNSS parameters in Table 2 and the methodology of Recommendation ITU-R M.1827 (which was developed in-part to facilitate compatibility between AM(R)S and fixed satellite service feeder links in the 5 091-5 150 MHz band), aggr
44、egate instantaneous power limits for the AM(R)S were determined. Those limits were based on not increasing the noise temperature of the RNSS satellite system receivers by more than 2%. 3.4 Interference to radio astronomy As noted above, the AM(R)S system planned for the 5 000-5 010 MHz band is an ai
45、rport surface LAN. The LAN will be used for a number of applications and limited to surface applications at major airports. Those characteristics will serve to help ensure protection of radio astronomy (RA) operating in the adjacent 4 990-5 000 MHz band since, in general, RA observatories are not lo
46、cated in close proximity to large airports due to the myriad of other radio-frequency signals present at those sites. As a result, in most cases geographic separation will suffice to ensure the compatibility of the planned AM(R)S systems with RA stations. In the few instances where RA observatories
47、are in relative proximity of major airports (e.g. Arecibo observatory in the United States or Jodrell Bank in the United Kingdom), it is expected that local coordination can be employed to solve any remaining issues. 4 Compatibility study results and discussion 4.1 RNSS The methodology in Recommenda
48、tion ITU-R M.1827 is used to compute the allowed power flux density (pfd) limit for the AM(R)S based on the RNSS protection criteria (Ts/Ts= 2%) and 250 in-view AM(R)S stations transmitting simultaneously at a given satellite in the 5 000-5 010 MHz2band. Assuming Table 2 characteristics for the RNSS
49、, the maximum aggregate interference level acceptable at the receiver input is IAgg-Rec: dB17=KTBIRecAggwhere: K: Boltzmanns constant (1.38 1023J/K); T: represents the receiver noise temperature (K); B: receiver bandwidth (Hz). 2Recommendation ITU-R M.1827 (Annex 1, Section II) assumes a maximum of 250 co-channel AM(R)S stations transmitting concurrently toward the FSS satellite, based on an assumption of 500 airports and a 50% duty cycle. 500 airports was based on the maximum number of existing towered airports in the United States. Because frequency assign
