1、 IEC 61280-2-8 Edition 1.0 2003-02 INTERNATIONAL STANDARD NORME INTERNATIONALE Fibre optic communication subsystem test procedures Digital systems Part 2-8: Determination of low BER using Q-factor measurements Procdures dessai des sous-systmes de tlcommunication fibres optiques Systmes numriques Par
2、tie 2-8: Dtermination de faible Taux dErreur Binaire (TEB) en utilisant des mesures du facteur Q IEC 61280-2-8:2003 colour inside THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2003 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reprod
3、uced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or IECs member National Committee in the country of the requester. If you have any questions about IEC copyright or have an enquiry about obtain
4、ing additional rights to this publication, please contact the address below or your local IEC member National Committee for further information. Droits de reproduction rservs. Sauf indication contraire, aucune partie de cette publication ne peut tre reproduite ni utilise sous quelque forme que ce so
5、it et par aucun procd, lectronique ou mcanique, y compris la photocopie et les microfilms, sans laccord crit de la CEI ou du Comit national de la CEI du pays du demandeur. Si vous avez des questions sur le copyright de la CEI ou si vous dsirez obtenir des droits supplmentaires sur cette publication,
6、 utilisez les coordonnes ci-aprs ou contactez le Comit national de la CEI de votre pays de rsidence. IEC Central Office Tel.: +41 22 919 02 11 3, rue de Varemb Fax: +41 22 919 03 00 CH-1211 Geneva 20 infoiec.ch Switzerland www.iec.ch About the IEC The International Electrotechnical Commission (IEC)
7、is the leading global organization that prepares and publishes International Standards for all electrical, electronic and related technologies. About IEC publications The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the latest edition
8、, a corrigenda or an amendment might have been published. Useful links: IEC publications search - www.iec.ch/searchpub The advanced search enables you to find IEC publications by a variety of criteria (reference number, text, technical committee,). It also gives information on projects, replaced and
9、 withdrawn publications. IEC Just Published - webstore.iec.ch/justpublished Stay up to date on all new IEC publications. Just Published details all new publications released. Available on-line and also once a month by email. Electropedia - www.electropedia.org The worlds leading online dictionary of
10、 electronic and electrical terms containing more than 30 000 terms and definitions in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical Vocabulary (IEV) on-line. Customer Service Centre - webstore.iec.ch/csc If you wish to give us you
11、r feedback on this publication or need further assistance, please contact the Customer Service Centre: csciec.ch. A propos de la CEI La Commission Electrotechnique Internationale (CEI) est la premire organisation mondiale qui labore et publie des Normes internationales pour tout ce qui a trait llect
12、ricit, llectronique et aux technologies apparentes. A propos des publications CEI Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possdez ldition la plus rcente, un corrigendum ou amendement peut avoir t publi. Liens utiles: Recherche de publicati
13、ons CEI - www.iec.ch/searchpub La recherche avance vous permet de trouver des publications CEI en utilisant diffrents critres (numro de rfrence, texte, comit dtudes,). Elle donne aussi des informations sur les projets et les publications remplaces ou retires. Just Published CEI - webstore.iec.ch/jus
14、tpublished Restez inform sur les nouvelles publications de la CEI. Just Published dtaille les nouvelles publications parues. Disponible en ligne et aussi une fois par mois par email. Electropedia - www.electropedia.org Le premier dictionnaire en ligne au monde de termes lectroniques et lectriques. I
15、l contient plus de 30 000 termes et dfinitions en anglais et en franais, ainsi que les termes quivalents dans les langues additionnelles. Egalement appel Vocabulaire Electrotechnique International (VEI) en ligne. Service Clients - webstore.iec.ch/csc Si vous dsirez nous donner des commentaires sur c
16、ette publication ou si vous avez des questions contactez-nous: csciec.ch. IEC 61280-2-8 Edition 1.0 2003-02 INTERNATIONAL STANDARD NORME INTERNATIONALE Fibre optic communication subsystem test procedures Digital systems Part 2-8: Determination of low BER using Q-factor measurements Procdures dessai
17、des sous-systmes de tlcommunication fibres optiques Systmes numriques Partie 2-8: Dtermination de faible Taux dErreur Binaire (TEB) en utilisant des mesures du facteur Q INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE U ICS 33.180.10 PRICE CODE CODE PRIX ISBN 978
18、-2-83220-354-5 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale Warning! Make sure that you obtained this publication from an authorized distributor. Attention! Veuillez vous assurer que vous avez obtenu cette publica
19、tion via un distributeur agr. colour inside 2 61280-2-8 IEC:2003 CONTENTS FOREWORD . 4 1 Scope . 6 2 Definitions and abbreviated terms . 6 2.1 Definitions . 6 2.2 Abbreviations . 6 3 Measurement of low bit-error ratios . 7 3.1 General considerations 7 3.2 Background to Q-factor 8 4 Variable decision
20、 threshold method . 10 4.1 Overview . 10 4.2 Apparatus 13 4.3 Sampling and specimens . 13 4.4 Procedure 13 4.5 Calculations and interpretation of results 14 4.6 Test documentation . 18 4.7 Specification information 18 5 Variable optical threshold method . 18 5.1 Overview . 18 5.2 Apparatus 19 5.3 It
21、ems under test. 19 5.4 Procedure for basic optical link 19 5.5 Procedure for self-contained system 20 5.6 Evaluation of results 21 Annex A (normative) Calculation of error bound in the value of Q 23 Annex B (informative) Sinusoidal interference method 25 Bibliography 31 Figure 1 A sample eye diagram
22、 showing patterning effects . 9 Figure 2 A more accurate measurement technique using a DSO that samples the noise statistics between the eye centres 9 Figure 3 Bit error ratio as a function of decision threshold level . 11 Figure 4 Plot of Q-factor as a function of threshold voltage . 11 Figure 5 Se
23、t-up for the variable decision threshold method . 13 Figure 6 Set-up of initial threshold level (approximately at the centre of the eye) . 13 Figure 7 Effect of optical bias . 18 Figure 8 Set-up for optical link or device test 20 Figure 9 Set-up for system test . 20 Figure 10 Extrapolation of log BE
24、R as function of bias 22 Figure B.1 Set-up for the sinusoidal interference method by optical injection . 26 Figure B.2 Set-up for the sinusoidal interference method by electrical injection . 28 Figure B.3 BER Result from the sinusoidal interference method (data points and extrapolated line) . 29 Fig
25、ure B.4 BER versus optical power for three methods 30 61280-2-8 IEC:2003 3 Table 1 Mean time for the accumulation of 15 errors as a function of BER and bit rate . 7 Table 2 BER as function of threshold voltage 15 Table 3 f ias a function of D i. 16 Table 4 Values of linear regression constants . 16
26、Table 5 Mean and standard deviation . 17 Table 6 Example of optical bias test . 21 Table B.1 Results for sinusoidal injection 27 4 61280-2-8 IEC:2003 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ FIBRE OPTIC COMMUNICATION SUBSYSTEM TEST PROCEDURES DIGITAL SYSTEMS Part 2-8: Determination of low BER usi
27、ng Q-factor measurements FOREWORD 1) The IEC (International Electrotechnical Commission) is a worldwide organisation for standardisation comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote international co-operation on all questions conc
28、erning standardisation in the electrical and electronic fields. To this end and in addition to other activities, the IEC publishes International Standards. Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this
29、preparatory work. International, governmental and non-governmental organisations liasing with the IEC also participate in this preparation. The IEC collaborates closely with the International Organisation for Standardisation (ISO) in accordance with conditions determined by agreement between the two
30、 organisations. 2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested National Committees. 3) The documents produced ha
31、ve the form of recommendations for international use and are published in the form of standards, technical specifications, technical reports or guides and they are accepted by the National Committees in that sense. 4) In order to promote international unification, IEC National Committees undertake t
32、o apply IEC International Standards transparently to the maximum extent possible in their national and regional standards. Any divergence between the IEC Standard and the corresponding national or regional standard shall be clearly indicated in the latter. 5) The IEC provides no marking procedure to
33、 indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with one of its standards. 6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. The IEC shall not be held respons
34、ible for identifying any or all such patent rights. International Standard IEC 61280-2-8 has been prepared by subcommittee 86C: Fibre optic systems and active devices, of IEC technical committee 86: Fibre optics. This bilingual version (2012-09) corresponds to the monolingual English version, publis
35、hed in 2003-02. The text of this standard is based on the following documents: FDIS Report on voting 86C/485/FDIS 86C/505/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. The French version of this standard has no
36、t been voted upon. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. 61280-2-8 IEC:2003 5 The committee has decided that the contents of this publication will remain unchanged until 2010. At this date, the publication will be reconfirmed; withdrawn; replaced by a r
37、evised edition, or amended. IMPORTANT The colour inside logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this document using a colour printer. 6 61280-2-8 IEC:20
38、03 FIBRE OPTIC COMMUNICATION SUBSYSTEM TEST PROCEDURES DIGITAL SYSTEMS Part 2-8: Determination of low BER using Q-factor measurements 1 Scope This part of IEC 61280 specifies two main methods for the determination of low BER values by making accelerated measurements. These include the variable decis
39、ion threshold method (Clause 4) and the variable optical threshold method (Clause 5). In addition, a third method, the sinusoidal interference method, is described in Annex B. 2 Definitions and abbreviated terms 2.1 Definitions For the purposes of this document, the following terms and definitions a
40、pply. 2.1.1 amplified spontaneous emission ASE impairment generated in optical amplifiers 2.1.2 bit error ratio BER the number bits in error as a ratio of the total number of bits 2.1.3 intersymbol interference ISI mutual interference between symbols in a data stream, usually caused by non-linear ef
41、fects and bandwidth limitations of the transmission path 2.1.4 Q-factor Q ratio of the difference between the mean voltage of the 1 and 0 rails, and the sum of their standard deviation values 2.2 Abbreviations cw Continuous wave (normally referring to a sinusoidal wave form) DC Direct current DSO Di
42、gital sampling oscilloscope DUT Device under test PRBS Pseudo-random binary sequence 61280-2-8 IEC:2003 7 3 Measurement of low bit-error ratios 3.1 General considerations Fibre optic communication systems and subsystems are inherently capable of providing exceptionally good error performance, even a
43、t very high bit rates. The mean bit error ratio (BER) may typically lie in the region 10 12to 10 20 , depending on the nature of the system. While this type of performance is well in excess of practical performance requirements for digital signals, it gives the advantage of concatenating many links
44、over long distances without the need to employ error correction techniques. The measurement of such low error ratios presents special problems in terms of the time taken to measure a sufficiently large number of errors to obtain a statistically significant result. Table 1 presents the mean time requ
45、ired to accumulate 15 errors. This number of errors can be regarded as statistically significant, offering a confidence level of 75 % with a variability of 50 %. Table 1 Mean time for the accumulation of 15 errors as a function of BER and bit rate BER Bits/s 10 610 710 810 910 1010 1110 1210 1310 14
46、10 151,0M 1,5 s 15 s 2,5 min 25 min 4,2 h 1,7d 17 d 170 d 4,7 years 47 years 2,0M 750 ms 7,5 s 75 s 750 s 2,1 h 21 h 8,8 d 88 d 2,4 years 24 years 10M 150 ms 1,5 s 15 s 2,5 min 25 min 4,2 h 1,7 d 17 d 170 d 4,7 years 50M 30 ms 300 ms 3,0 s 30 s 5,0 min 50 min 8,3 h 3,5 d 35 d 350 d 100M 15 ms 150 ms
47、 1,5 s 15 s 2,5 min 25 min 4,2 h 1,7 d 17 d 170 d 500M 3 ms 30 ms 300 ms 3,0 s 30 s 5,0 min 50 min 8,3 h 3,5 d 35 d 1,0G 1,5 ms 15 ms 150 ms 1,5 s 15 s 2,5 min 25 min 4,2 h 1,7 d 17 d 10G 150 s 1,5 ms 15 ms 150 ms 1,5 s 15 s 2,5 min 25 min 4,2 h 1,7 d 40G 38 s 380 s 3,8 ms 38 ms 380 ms 3,8 s 38 s 6,
48、3 min 63 min 10,4 h 100G 15 s 150 s 1,5 ms 15ms 150 ms 1,5 s 15 s 2,5 min 25 min 4,2 h The times given in Table 1 show that the direct measurement of the low BER values expected from fibre optic systems is not practical during installation and maintenance operations. One way of overcoming this diffi
49、culty is to artificially impair the signal-to-noise ratio at the receiver in a controlled manner, thus significantly increasing the BER and reducing the measurement time. The error performance is measured for various levels of impairment, and the results are then extrapolated to a level of zero impairment using computational or graphical methods according t
