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 theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2010 SAE International All rights reserved. No part of this publication ma
3、y be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside US
4、A) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AS5750AAEROSPACESTANDARDAS5750 REV. A Issued 2009-01 Revised 2010-07Loss Budget Specification f
5、or Fiber Optic Links RATIONALEThe aerospace industry requires precise standards for avionics system design. To ensure that the aerospace fiber optics industry also adopts these same high standards, it is essential that a common set of fiber optic system design procedures be established. This documen
6、t outlines procedures needed for digital avionics fiber optic link system design that help to assure it complies with aerospace industry best practices. Revision A provides an update to aerospace industry best practices.This document also provides an easily specified document for use during a comple
7、x system acquisition referencing back to previously approved standard AS5603 for the detailed calculations. 1. SCOPE This document defines a quantified means of specifying a digital fiber optic link loss budget: x Between end users and system integrators x Between system integrators and subsystem su
8、ppliers x Between subsystem suppliers and component vendors The standard specifies methods and the margin required for categories of links. 2. APPLICABLE DOCUMENTS The following publications for a part of this document to the extent specified herein. The latest issue of SAE publications shall apply.
9、 The applicable issue of the other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable
10、 laws and regulations unless a specific exemption has been obtained. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.AS5603 Digital Fiber Optic Loss Budget M
11、ethodology for Aerospace Platforms SAE AS5750A Page 2 of 43. REQUIREMENTS In order to perform a digital optical loss budget calculation, a method and several parameters must be selected and defined.Standards document AS5603 details three methods for calculating a digital optical loss budget. These i
12、nclude the Worst Case Method, the Statistical Method, and the Numerical (Simulation) Method. As described by AS5603, these methods require increasing effort but provide increasing accuracy. The entity requesting the digital optical loss budget calculation shall select one of methods listed in Table
13、1. If the requesting entity does not select one of the methods listed in Table 1, the Worst Case Method shall be selected. The entity performing the digital optical loss budget calculation shall use one of the allowed methods corresponding to the selected method specified in Table 1. TABLE 1 - ALLOW
14、ED DIGITAL OPTICAL LOSS BUDGET METHODS Selected Method Allowed Method of Calculation Worst Case Statistical Numerical(Simulation)I Worst Case Allowed Allowed Allowed II Statistical X Allowed Allowed III Numerical (Simulation) X X Allowed Standards document AS5603 lists two parameters that are requir
15、ed for calculating a digital optical loss budget and one parameter that is suggested. The first required parameter is the required margin, MREQ, of the optical system. The second required parameter is the confidence level, C, needed for meeting the MREQof the system. The suggested parameter is the r
16、equired saturation margin, MREQ(SAT),of the optical system. Because these parameters are inherently linked together, relevant categories defining these parameters are called out in Table 2 of this document. The entity requesting the digital optical loss budget calculation shall select one of the cat
17、egories in Table 2. If the requesting entity does not select one of the categories listed in Table 2, Category B shall be selected. TABLE 2 - DIGITAL OPTICAL LOSS BUDGET CATEGORIES AND DEFINED PARAMETERS CategoryRequired Optional Intended Use MREQC MREQ(SAT)dB % dB A 1.5 99.9999 0 Flight Critical Sy
18、stems B 3 99.99 C 4.5 99 0 D 1.5 99.99 Mission Critical Systems E 3 99 0 F 4.5 95 G 0 99.99 0 Non-MissionCritical Systems H 1.5 99 I 3 95 0 J 0 95 Prototypes Z As Defined As Defined As Defined As Defined SAE AS5750A Page 3 of 4Category A, B, and C are intended for flight critical systems (flight saf
19、ety or safety of flight) and for systems with high availability requirements. Note that these three categories are intended to yield statistically equivalent performance. Category D, E, and F are intended for mission critical systems (mission essential). Note that these three categories are intended
20、 to yield statistically equivalent performance. Category G, H, and I are intended for non-mission critical systems (non-mission essential). Note that these three categories are intended to yield statistically equivalent performance. Category J is intended for experimental and demonstration systems w
21、ith limited lifetimes. This category is also used to show feasibility of systems where the exact components and cable runs are not production-defined, such as experimental systems. Category Z is intended for systems where the requesting entity and the performing entity have negotiated specific param
22、eters for the target system. 4. DOCUMENTATION Unless otherwise specified, the following data shall be reported: a. Title of results: Digital Fiber Optic Loss Budget Calculation b. Identification of standard used (AS5750) c. Identification of fiber optic link whose loss budget is being calculated (ad
23、equate information accurately documenting link physical characteristics and operational parameters, e.g. fiber type, length, wavelength, etc.). d. Date the loss budget calculation was performed e. Loss budget calculation method used (I Worst Case, II Statistical, or III Numerical (Simulation) f. Ide
24、ntification of loss budget category (A, B, C, etc) g. For category Z, defined parameter values for MREQ, C, and optionally MREQ(SAT)h. Numerical results of the loss budget calculation i. Pass / fail results of the loss budget calculation United States military applications require that the following
25、 information shall also be reported for each test. For other (nonmilitary) applications, this information need not be reported but shall be available for review upon request. j. Responsible entity performing the loss budget calculation 5. SPECIFICATION AND INFORMATION REQUIREMENTS The following deta
26、ils shall be specified when using this standard: a. Base loss budget calculation method to be used (I Worst Case, II Statistical, or III Numerical (Simulation). If no method has been selected, I Worst Case is selected by default b. Loss budget calculation category to be used (A, B, C, etc). If no ca
27、tegory has been selected, category A is selected by default c. If loss budget calculation category Z, the specific defined parameter values for MREQ, C, and optionally MREQ(SAT)d. Relevant physical and operational parameters, e.g. fiber type, length, wavelength, etc, SAE AS5750A Page 4 of 46. NOTES
28、6.1 A change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY SAE COMMITTEE AS-3, FIBER OPTICS AND APPLIED PHOTONICS
