1、 Report ITU-R M.2197(11/2010)Technical characteristics and operational objectives for wireless avionicsintra-communications (WAIC)M SeriesMobile, radiodetermination, amateurand related satellites servicesii Rep. ITU-R M.2197 Foreword The role of the Radiocommunication Sector is to ensure the rationa
2、l, 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 functions of the Radiocommu
3、nication 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 referenced in Annex 1 of Re
4、solution 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 the ITU-R patent informatio
5、n 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 production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed ser
6、vice 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-satellite and fixed service systems SM Sp
7、ectrum 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, 2011 ITU 2011 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permissio
8、n of ITU. Rep. ITU-R M.2197 1 REPORT ITU-R M.2197 Technical characteristics and operational objectives for wireless avionics intra-communications (WAIC) (Question ITU-R 249/5) (2010) TABLE OF CONTENTS Page Objective 3 1 Introduction 3 2 Discussion . 3 2.1 Substitution of wiring . 4 2.2 Enhance relia
9、bility 5 2.3 Additional functions . 5 3 WAIC system classification . 6 3.1 Classification process description . 6 3.1.1 System data rate classification . 6 3.1.2 System location classification 6 3.1.3 Class definition 7 3.2 Detailed description of applications by class 7 3.2.1 Classification LI . 7
10、3.2.2 Classification LO . 9 3.2.3 Classification HI 11 3.2.4 Classification HO . 14 4 Typical wireless system characteristics 16 4.1 Reference architecture concept . 16 4.2 Physical architecture . 16 4.2.1 Applications within aircraft structure 17 4.2.2 Applications outside aircraft structure (LO an
11、d HO) . 25 2 Rep. ITU-R M.2197 Page 4.3 Data transfer requirements 31 4.3.1 Factors influencing data transfer requirements 31 4.3.2 Methodology for quantifying data transfer requirements 33 4.3.3 WAIC data transfer requirements for application class LI 33 4.3.4 WAIC data transfer requirements for ap
12、plication class LO . 34 4.3.5 WAIC data transfer requirements for application class HI 35 4.3.6 WAIC data transfer requirements for application class HO 35 4.4 WAIC propagation characteristics 36 4.4.1 Path-loss inside aircraft 36 4.4.2 Propagation outside aircraft . 39 4.5 RF characteristics 39 4.5
13、.1 Antenna system characteristics 40 4.5.2 Shared transmitter/receiver characteristics 43 4.5.3 Receiver characteristics 44 4.5.4 Transmitter characteristics . 45 4.5.5 Spectrum usage and potential channelization plans . 46 4.6 Relationship between frequency, bandwidth, and transmit power level for
14、WAIC systems 49 4.6.1 Power levels for LI and LO systems 50 4.6.2 Power levels for HI and HO systems . 52 5 Summary . 54 5.1 Technical considerations for LI and LO class systems 54 5.2 Technical considerations for HI and HO class systems 54 6 Conclusion 55 Annex 1 Glossary 55 Rep. ITU-R M.2197 3 Obj
15、ective This Report provides technical characteristics and operational objectives of WAIC systems for a single aircraft. This Report does not give an indication of selected frequency bands. The content presented in this Report hence represents the current state of information on WAIC applications ant
16、icipated by the international commercial aviation industry. This Report analyses a representative WAIC system for a single aircraft and derives the maximum required transmission power for low and high, inside and outside application classes as a function of a theoretical carrier frequency and bandwi
17、dth. The results presented in Figs 11 to 17 provide insight into potential trade-offs between the technical characteristics; transmission power, bandwidth and carrier frequency. It is assumed that WAIC systems will require a maximum transmit power of approximately 10 dBm between 1 GHz and 10 GHz giv
18、en the needs of energy-limited sensor nodes. It is also assumed that WAIC systems may require a maximum transmit power of up to 30 dBm between 10-66 GHz. 1 Introduction The commercial aviation industry is developing the next generation of aircraft to provide airlines and the flying public more cost-
19、efficient, safer, and more reliable aircraft. One important way of doing this is to reduce aircraft weight. It is believed that wireless technologies can reduce the weight of systems on an aircraft thereby providing significant cost savings. Reducing the amount of fuel required to fly can also reduc
20、e costs and benefit the environment. Installed wireless avionics intra-communications (WAIC) systems are one way to derive these benefits. WAIC systems consist of radiocommunications between two or more points on a single aircraft. Points of communication may include integrated wireless components a
21、nd/or installed components of the system. In all cases communication is assumed to be part of a closed, exclusive network required for operation of the aircraft. WAIC systems do not provide air-to-ground or air-to-air communications. It is anticipated that WAIC systems will only be used for safety-r
22、elated aircraft applications Also, WAIC systems transmissions may not be limited to the interior of the aircraft structure, depending on the type of aircraft. For example, sensors mounted on the wings or engines could communicate with systems within the airplane. WAIC systems may be used on regional
23、, business, wide-body, and two-deck aircraft, as well as helicopters. These different aircraft types may place different requirements on the WAIC systems and may also impact the type of propagation path between the WAIC transmitter and receiver. As the reliance on wireless technology continues to ex
24、pand, the use of WAIC systems to transmit information important to the safe and efficient operation of an aircraft may provide significant advantages over current wired systems. This Report focuses on technical characteristics and operational objectives of potential WAIC systems on a single aircraft
25、 and does not include bandwidth requirements. The discussion on candidate frequency bands is also not addressed in this Report. This Report does not cover the impact of using wireless technologies for this purpose. 2 Discussion WAIC systems are envisioned to provide communications over short distanc
26、es between points on a single aircraft. WAIC systems are not intended to provide communications, in any direction, between points on an aircraft and another aircraft, terrestrial systems or satellites. WAIC systems are intended to support data, voice and video (to monitor different areas on the airc
27、raft) communications between systems on an aircraft including communications systems used by the 4 Rep. ITU-R M.2197 crew. It is also envisioned that wireless sensors located at various points on the aircraft will be used to wirelessly monitor the health of the aircraft structure and all of its crit
28、ical systems, and communicate information within the aircraft to those who can make the best use of such information. Points of communication may include integrated wireless components and/or installed components of the system. In all cases communication between two points on a single aircraft is as
29、sumed to be part of a closed, exclusive network required for operation of the aircraft. WAIC systems are not intended to provide air-to-ground communications or communications between two or more aircraft. They are also not intended to include communications with consumer devices, such as radio loca
30、l area network (RLAN) devices that are brought on board the aircraft by passengers or for in-flight entertainment applications. WAIC systems are envisioned to offer aircraft designers and operators many opportunities to improve flight safety and operational efficiency while reducing costs to the avi
31、ation industry and the flying public. Because WAIC systems are installed on aircraft, they are as transient as the aircraft itself and will cross national boundaries. Therefore, the ITU-R, national and international organizations involved in radiocommunications and air travel should work together in
32、 addressing this issue. The scope of WAIC applications is limited to applications that relate to the safe, reliable and efficient operation of the aircraft as specified by the International Civil Aviation Organization (ICAO). It is intended that WAIC systems will only be used for safety-related airc
33、raft applications. WAIC systems are envisioned to provide significant benefits to all who use the sky to travel. Some of the potential benefits of WAIC systems are described below. 2.1 Substitution of wiring Cabling and wiring present a significant cost to the aircraft manufacturer, operator, and ul
34、timately the flying public. Costs include the wiring harness designs, labour-intensive cable fabrication, reliability and replacement costs of connectors, as well as the associated operating costs of flying copper and connectors that represent 2-5% of an aircrafts weight. Wiring harness design is on
35、e of the critical factors that determine the time required to design a new aircraft, requiring the designers to specify and determine the routes for miles of wire onboard the aircraft. This includes providing separate routing paths for redundant wiring, so that a single point failure does not affect
36、 redundant circuits, and enables safety critical systems to be properly isolated from other system wiring. Wireless products offer solutions that can reduce the time and costs associated with wiring harness design, harness installation design, aircraft manufacturing time, and aircraft lifecycle cost
37、s. Wiring also constitutes over 50% of the instances of electromagnetic interference on board aircraft. Wiring can act as antennas and collect unwanted energy that may impact interconnected system immunity. Wiring can also radiate energy with the risk of inducing electro-magnetic interference on sur
38、rounding systems. Providing wireless links, in lieu of wiring can provide connectivity without the need for redundant wiring harnesses that are specific to a specific aircraft type, resulting in economies of scale for small, medium and large aircraft. As an airframe is utilized during its lifetime,
39、it may be necessary to install new sensors to monitor portions of the aircraft structure or aircraft systems either as a result of incident or accident awareness or as a result of the availability of new types of sensing technology. On current aircraft, adding a new sensor is very expensive due to t
40、he requirements to install wiring, connections to the central processing system, and modifications to software. WAIC networks could allow new sensors to be mounted with much less difficulty and expense, and enable easier modification of systems and structural monitoring throughout the life of the ai
41、rcraft, which typically exceeds 25 years. Rep. ITU-R M.2197 5 2.2 Enhance reliability Wiring is a significant source of field failures and maintenance costs. It is extremely difficult to troubleshoot and repair such failures in aircraft system wiring which occur primarily at interface points where c
42、onnectors, pins, and sockets come together. The large number of parts and human error also contribute to failure at these interface points. A wireless system may significantly reduce electrical interfaces and thus significantly increase system reliability. Wireless technologies are intended to offer
43、 the means to implement systems that enhance reliability. By having fewer wires on an aircraft, the need for wire maintenance to remediate chafing conditions, aging wiring and associated fire hazards is reduced, thereby improving the safety and reliability of the aircraft. Adding new sensors on an a
44、ircraft to monitor functions such as equipment cooling status that measure the temperature around components to provide a more accurate status of equipment cooling, has the potential to improve the reliability of aircraft. The introduction of these additional sensors has been limited due to wiring w
45、eight and cost impact, but they might be implemented using wireless technology. Aircraft data networks could also take advantage of redundant communication paths offered through mesh networks, which are not cost effective in hard-wired form. Critical aircraft functions must be fault-tolerant, which
46、leads aircraft designers to include redundant components and redundant wiring harnesses. However, the use of identical technology (in this case duplicate wiring harnesses) to provide fault tolerance can make a design susceptible to “common mode failures” such as fire or lightning strike. The use of
47、a wireless link as a backup to a wiring harness introduces redundancy through dissimilar means that can in fact enhance reliability in some critical situations, and can provide connectivity without the need for redundant wiring harnesses specific to a particular aircraft type. 2.3 Additional functio
48、ns Wireless technologies are also envisioned to provide new functionalities to aircraft manufacturers and operators. Manufacturers are provided additional installation options for previously wired systems, while operators are afforded more opportunities to monitor aircraft systems. Currently, there
49、are few dedicated sensors for monitoring the health of aircraft systems and structure as the aircraft ages. Wireless technologies could provide additional opportunities to monitor more systems without increasing the aircrafts weight. Some additional functions that could be incorporated on an aircraft with wireless technology that cannot be performed with wires include engine rotator bearing monitoring and lightning damage sensors. Reliably routing wiring harnesses to engine rotator bearings is impractical due to the movement of parts. Utilizing a special temp
