1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
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4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AIR6005 AEROSPACE INFORMATION REPORT AIR6005 Issued 2009-12 General Requirements for WDM Backbon
5、e Networks RATIONALE It is desirable to architect a new standard Wavelength Division Multiplexed (WDM) fiber optic network architecture for aerospace platforms that will not only supplement current aircraft system, but can enable replacement of applicable legacy interconnects to maximize the benefit
6、s of fiber optic network technology and revolutionize networking in aerospace platforms through the use of a flexible, scalable and high capacity networking infrastructure. One of the objectives of a WDM-based solution is to enable migrating these legacy communications needs over to a lighter weight
7、, optically multiplexed WDM network. In this manner, the weight of the typically heavy electrical cable harnesses can be eliminated, justifying the introduction of optical communications, while enabling new applications that can be supported by the available optical fiber bandwidth. This document de
8、scribes network interfaces and requirements a WDM Optical Backbone network (WDM OBN), a transparent optical network which contains optical components and optical interfaces to perform optical transport, optical add/drop, optical amplification, optical routing, and optical switching functions. TABLE
9、OF CONTENTS 1. SCOPE 4 2. REFERENCES 4 2.1 SAE Publications . 4 2.2 ANSI Publications 4 2.3 IEC Publications 5 2.4 U.S. Government Publications 5 2.5 Applicable References . 5 3. INTRODUCTION . 6 3.1 Motivation 6 3.2 Network Abstraction 7 3.3 System Applications 8 3.4 WDM LAN Challenges and Rational
10、e . 8 3.5 Purpose . 10 3.5.1 Requirements Format: . 11 3.5.2 Taxonomy 11 3.5.3 Assumptions 14 3.5.4 Overview of Related Documents . 14 3.6 Structure of Document . 16 3.7 Terminology . 16 4. NETWORKS IN AVIONIC APPLICATIONS 17 4.1 Existing Avionic Network Applications . 17 4.1.1 Market Drivers . 17 4
11、.1.2 Aircraft Systems 18 4.1.3 Cable Plant 22 4.1.4 Critical Network Characteristics 23 4.1.5 Aircraft Systems Differentiators . 27 4.1.6 Connection Latency Andrew Lee, Sept. 12. 2006, IEEE/AVFOP conference, Annapolis, MD The Theory of Networking and Architectures, Casey Reardon, Oct. 26, 2006, SAE
12、WDM LAN task group meeting, Jacksonville, Florida Virtual Prototyping of WDM Avionics Networks presentation by Casey B. Reardon, Ian A. Troxel, and Alan D. George; HCS Research Laboratory, University of Florida; September 2005, IEEE/AVFOP Conference Presentation. High Performance Single Mode Fiber O
13、ptic Cable for Aerospace Applications, by Graldine Trouillard and Aurlien Bergonzo RONIA Results: WDM-based Networks in Aircraft Applications, Sarry F. Habiby and Michael J. Hackert, IEEE/AVFOP 2008 Conference, October 2008, San Diego, CA. “Open System Interconnection Model and Notation” ITU-T Recom
14、mendation X.200, July 1994. “Impact of filter concatenation on the performance of metropolitan area optical networks utilizing directly modulated lasers”, Ioannis Tomkos, Robert Hesse, Neo Antoniades, and Aleksandra Boskovic, OFC 2001 Conference, WBB4. Khrais, N., Elrefaie, A., Wagner, R., and Ahmed
15、, S., IEEE Photonic Technology. Letters., vol. 7, p. 1348-1350, 1995. Khrais, N. N., Elrefaie, A., and Wagner, R. E., Electron. Lett., vol. 31, p. 1179-1180, 1995. Zhensheng Jia, Jianjun Yu, Lei Zong, and Gee-Kung Chang, “Transport of 8x2.5-Gb/s Wireless Signals over Optical Millimeter Wave through
16、12 Straight-Line WSSs and 160-km Fiber for Advanced DWDM Metro Networks,” in Optical Fiber Communication Conference and Exposition and The National Fiber Optic Engineers Conference, OSA Technical Digest (CD) (Optical Society of America, 2008), paper OMO3. SAE AIR6005 Page 6 of 88 3. INTRODUCTION 3.1
17、 Motivation The purpose of this document is to define requirements for optical networks in aircraft applications and understand the rationale behind them. The specifications derived from these requirements will enable aerospace network engineers and designers to design and use wavelength division mu
18、ltiplexed (WDM) systems and technology to implement a flexible, scalable and upgradeable optical network supporting the systems and subsystems aboard an avionics platform. While the physical plant definition will differ from platform to platform, the method for network access and transport across a
19、backbone single-mode fiber network can be standardized, e.g. as in access and transport across an Ethernet or fiber channel Local Area Network (LAN). Additional context in terms of scope and purpose are provided in Sections 1 and 3.5. This document provides inputs (requirements) for the AS5659 Speci
20、fications document being developed by the SAE AS-3A1 WDM LAN Development Subcommittee. WDM technology is viewed as a basis for the desired networking solution as it enables support of many different legacy and novel applications (through transparency); it provides optical layer scalability, both in
21、terms of overall bandwidth and the number of provisioned applications, through the assignment of wavelengths or shared wavelengths. Many WDM commercial telecom and datacom systems exist that incorporate a number of existing, commercially supported standards, yet there are technology challenges (e.g.
22、 integration, packaging outlined below) to overcome before WDM components and networks can be adopted for the targeted applications. By developing a WDM LAN standard we expect to define the critical parameters that can facilitate deployment of standardized systems. These standards will insure intero
23、perability between the optical equipment network elements within these systems. The commercial industry is motivated to utilize these standards to minimize the amount of tailored development of engineered systems. The development of a WDM LAN standard is expected to have similar broad applicability
24、for avionics and ship-board applications. The main focus of this document is on the optical backbone network (OBN) portion of a WDM LAN based on single mode fiber to enable a scalable optical network aboard aircraft, hereafter referred to as a WDM Optical Backbone Network or WDM OBN. Nonetheless, we
25、 also provide a taxonomy (Sec. 3.5.2) that delineates a range of cable plant, application and optical network architectures that can be specified using this document as a baseline. As such, this document is intended to have a broad scope and enable an “inclusive” standard that can be applied to airb
26、orne as well as ship-board and other mobile network systems. The various platforms envisioned include those depicted in Table 1. Additional networking categories of interest include: a. On Board access networks (to WDM LAN OBN) 1. Passive Optical Networks 2. Point to Point Links b. Interfaces to ext
27、ernal networks Consequently, the set of optical backbone network requirements identified in this document will provide the framework for an upgradable cable infrastructure network over time. TABLE 1 POTENTIAL WDM LAN PLATFORMS Military Aircraft Ships 1) Transport 2) Tactical 3) Rotorcraft 4) UAVs 5)
28、 Aircraft Carriers 6) Destroyers 7) EW Ships 8) Small Boats Commercial 9) Transport (Passenger it is challenging to manage the life cycle cost of numerous unrelated networks which use different standards and different connection methods, while they all are tightly packed into the same physical platf
29、orm. An important part of installation and maintenance of equipment aboard military platforms has to do with space, weight, and access. For example, replacement of wire and cable infrastructure aboard a fighter aircraft can be invasive and expensive, causing unintended collateral effects on other ai
30、rcraft subsystems. Diversity of protocols typically exists with these systems resulting in incompatibility and the need for cable plant upgrades when interconnection of system elements is required. Developing a network layer that can provide novel functionality aboard an aircraft, such as through a
31、WDM OBN, can provide a transparent optical layer that enables the connectivity and performances desired, while still offering a level of network layer scalability and flexibility. BackboneNetworkNetCntrlToday the physical layer uses multiple overlay linksVision: Aircraft Backbone NetworkNetworking r
32、equires novel infrastructure, access and controlsAdding new equipment requires physical changes to cable or bus infrastructureAdding new equipment is simplifiedvia standard interface tooptical backbone networkFIGURE 1 - WDM LAN OBN: NETWORK ABSTRACTION; EVOLUTION OF AIRCRAFT NETWORKS The primary bas
33、is for introducing a WDM LAN into any platform is to group future-proof parts of the wire and cable infrastructure, dedicated to data communications, into a single entity. The intent is that an OBN within the WDM LAN will be designed and installed once, and provides connectivity directly to all subs
34、ystems which require high bandwidth communication. (Signals from low bandwidth devices may be multiplexed together before the aggregated signals access the backbone network). The WDM OBN will be operated and maintained as a separate system, providing networked communication services to devices that
35、are connected to it. Health monitoring and problem diagnosis can be performed with simple network algorithms, so the need to physically access remote nodes would be done only as necessary. Future upgrades of the systems and applications aboard aircraft will be achieved by connecting equipment to the
36、 backbones Optical Network Elements (ONE) and Optical Fiber Interconnects (OFI) defined in more detail below. The client equipment nodes are connected to the OBN using standards-based Network Access Interfaces (NAI), without invasive and costly wire or optical cable upgrades. The ONE and OFI are int
37、erconnected to each other through standards-based optical Backbone Network Interfaces (BNIs). Additional details regarding the WDM OBN interfaces (NAI and BNI) of the ONEs and OFIs are provided in Section 5 of this document. SAE AIR6005 Page 8 of 88 Fundamental requirements exist to ensure that evol
38、ving demands for improved efficiency and throughput on aircraft networks can be met. Creation of a network-centric configuration is the logical approach in meeting the requirements. Understanding the systems and application performance requirements is a precursor to the design of a general purpose W
39、DM LAN that supports present and future device communication. A WDM LAN and the OBN within it are expected to provide improved flexibility in supporting new services on the network while reducing the complexity associated with physical reconfiguration with the addition or removal of network elements
40、. It also provides a potential for accommodating security (such as Multiple Independent Levels of Security, MILS) as a managed network function. 3.3 System Applications In avionics systems the allocation of network resources are typically required for the following systems (these systems are defined
41、 in Section 4.1): Communication, Navigation and Traffic Identification/Surveillance Vehicle Management System Mission/Flight Plan Processing Core Computing Displays and Sensors Cabin Systems Electronic Warfare Stores Management Systems As shown in Figure 1, the system applications are currently impl
42、emented as a collection of data links rather than through a networked approach; by migrating to an optical fiber infrastructure and introducing WDM technology that enable provisioning of the large number of wavelengths (bandwidth resources) available in optical fiber, it is expected that a significa
43、nt improvement in overall system capacity, latency, redundancy and reliability can be achieved. 3.4 WDM LAN Challenges and Rationale The use of a WDM LAN introduces a set of physical layer and operational challenges and requirements that need to be addressed. These challenges point to specific topic
44、s and technical areas where standardization is needed. These include specification of the WDM OBN network interfaces (i.e. BNI and NAI), as well as network operations and management/control. Also, at the optical data plane layer, the wavelength allocation and inter channel performance requirements (
45、e.g. interference or crosstalk) need to be defined. Since the aerospace industry makes a direct correlation between weight and cost, reduction in overall system weight translates into valuable payload that a platform can carry, the loiter or mission time that an aircraft can maintain, and the amount
46、 of fuel a platform requires to first get aloft and then to stay aloft. Therefore, minimizing size, weight, and power (SWAP) is a critical metric for the aerospace industry. In turn, SWAP drives the highest degree of integration for optoelectronic devices. While critical to aerospace applications, w
47、eight reduction has a lesser priority for terrestrial datacom and telecom networking. Component development for these commercial applications is driven more by cost reduction and performance, respectively. Although not obvious, packaging of currently available discreet commercial components incurs a
48、 high packaging cost (to survive the harsh aerospace environment) which is weight and space prohibitive. Consequently, an enabler for a low cost OBN within a WDM LAN is the component miniaturization and integration of the multiple functions needed to create the network connections within an OBN. Thu
49、s, a number of new technologies which provide the possibility of this integration (e.g. silicon photonics) could in fact make OBNs and WDM LANs a viable reality. The contrast between commercial data communications and aerospace application also can be drawn by comparing the importance of reliability and maintainability. Between the complexity of the system (which might be compared to the telecommunications grid) and
