EN IEC 61280-2-8:2021

Fibre optic communication subsystem test procedures - Part 2-8: Digital systems - Determination of low BER using Q-factor measurements

IEC 61280-2-8:2021 is available as IEC 61280-2-8:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition. IEC 61280-2-8:2021 specifies two main methods for the determination of low BER values by making accelerated measurements. These include the variable decision threshold method (Clause 5) and the variable optical threshold method (Clause 6). In addition, a third method, the sinusoidal interference method, is described in Annex B. This second edition cancels and replaces the first edition published in 2003. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - correction of errors in Formula (8) in 5.5.2 and in a related formula in 5.5.3; - correction of errors in the references to clauses, subclauses, figures, procedures, and in the Bibliography; - alignment of the terms and definitions in 3.1 with those in IEC 61281-1.

Prüfverfahren für Lichtwellenleiter-Kommunikationsuntersysteme - Teil 2-8: Digitale Systeme - Bestimmung von geringen Bitfehlerraten (BER) mit Hilfe von Q-Faktor Messungen

Procédures d’essai des sous-systèmes de télécommunications fibroniques - Partie 2-8: Systèmes numériques - Détermination de faibles valeurs de BER en utilisant des mesures du facteur Q

IEC 61280-2-8:2021 est disponible sous forme de IEC 61280-2-8:2021 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente. L'IEC 61280-2-8:2021 spécifie deux méthodes principales permettant de déterminer de faibles valeurs de BER en réalisant des mesures accélérées. Ces méthodes utilisent soit un seuil de décision variable (Article 5), soit un seuil optique variable (Article 6). De plus, une troisième méthode fondée sur le brouillage sinusoïdal est décrite à l’Annexe B. Cette deuxième édition annule et remplace la première édition parue en 2003. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente: - correction d’erreurs dans la Formule (8) en 5.5.2 et dans une formule associée en 5.5.3; - correction d’erreurs dans les références aux articles, paragraphes, figures et procédures, ainsi que dans la bibliographie; - alignement des termes et définitions en 3.1 sur ceux de l’IEC 61281-1.

Postopki preskušanja optičnega komunikacijskega podsistema - Digitalni sistemi - 2-8. del: Ugotavljanje nizkega razmerja bitne napake (BER) s pomočjo meritev Q-faktorja (IEC 61280-2-8:2021)

General Information

• Status: Published
• Publication Date: 15-Apr-2021
• ICS: 33.180.10 - Fibres and cables
• Technical Committee: CLC/SR 86C - Fibre optic systems and active devices
• Drafting Committee: IEC/SC 86C - IEC_SC_86C
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 16-Apr-2021
• Completion Date: 16-Apr-2021
• Ref Project: SIST EN IEC 61280-2-8:2021 - Fibre optic communication subsystem test procedures - Digital systems - Part 2-8: Determination of low BER using Q-factor measurements (IEC 61280-2-8:2021)

Relations

• Replaces: EN 61280-2-8:2003 - Fibre optic communication subsystem test procedures - Digital systems - Part 2-8: Determination of low BER using Q-factor measurements
• Effective Date: 26-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2021
Nadomešča:
SIST EN 61280-2-8:2004
Postopki preskušanja optičnega komunikacijskega podsistema - Digitalni sistemi -
2-8. del: Ugotavljanje nizkega razmerja bitne napake (BER) s pomočjo meritev Q-
faktorja (IEC 61280-2-8:2021)
Fibre optic communication subsystem test procedures - Digital systems - Part 2-8:
Determination of low BER using Q-factor measurements (IEC 61280-2-8:2021)
Prüfverfahren für Lichtwellenleiter-Kommunikationsuntersysteme - Teil 2-8: Digitale
Systeme - Bestimmung von geringen Bitfehlerraten (BER) mit Hilfe von Q-Faktor
Messungen (IEC 61280-2-8:2021)
Procédures d’essai des sous-systèmes de télécommunications fibroniques - Partie 2-8:
Systèmes numériques - Détermination de faibles valeurs de BER en utilisant des
mesures du facteur Q (IEC 61280-2-8:2021)
Ta slovenski standard je istoveten z: EN IEC 61280-2-8:2021
ICS:
33.180.01 Sistemi z optičnimi vlakni na Fibre optic systems in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61280-2-8

NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2021
ICS 33.180.10 Supersedes EN 61280-2-8:2003 and all of its
amendments and corrigenda (if any)
English Version
Fibre optic communication subsystem test procedures - Part 2-8:
Digital systems - Determination of low BER using Q-factor
measurements
(IEC 61280-2-8:2021)
Procédures d'essai des sous-systèmes de Prüfverfahren für Lichtwellenleiter-
télécommunications fibroniques - Partie 2-8: Systèmes Kommunikationsuntersysteme - Teil 2-8: Digitale Systeme -
numériques - Détermination de faibles valeurs de BER en Bestimmung von geringen Bitfehlerraten (BER) mit Hilfe
utilisant des mesures du facteur Q von Q-Faktor Messungen
(IEC 61280-2-8:2021) (IEC 61280-2-8:2021)
This European Standard was approved by CENELEC on 2021-04-06. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61280-2-8:2021 E

European foreword
The text of document 86C/1708/FDIS, future edition 2 of IEC 61280-2-8, prepared by SC 86C "Fibre
optic systems and active devices" of IEC/TC 86 "Fibre optics" was submitted to the IEC-CENELEC
parallel vote and approved by CENELEC as EN IEC 61280-2-8:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022-01-06
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-04-06
document have to be withdrawn
This document supersedes EN 61280-2-8:2003 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 61280-2-8:2021 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 61281-1 NOTE Harmonized as EN IEC 61281-1

IEC 61280-2-8 ®
Edition 2.0 2021-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Fibre optic communication subsystem test procedures –

Part 2-8: Digital systems – Determination of low BER using Q-factor

measurements
Procédures d’essai des sous-systèmes de télécommunications fibroniques –

Partie 2-8: Systèmes numériques – Détermination de faibles valeurs de BER en

utilisant des mesures du facteur Q

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-9497-0

– 2 – IEC 61280-2-8:2021 © IEC 2021
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions, and abbreviated terms . 6
3.1 Terms and definitions . 6
3.2 Abbreviated terms . 7
4 Measurement of low bit-error ratios . 7
4.1 General considerations . 7
4.2 Background to Q-factor . 8
5 Variable decision threshold method . 10
5.1 Overview. 10
5.2 Apparatus . 13
5.3 Sampling and specimens . 13
5.4 Procedure . 13
5.5 Calculations and interpretation of results . 15
5.5.1 Sets of data . 15
5.5.2 Convert BER using inverse error function . 16
5.5.3 Linear regression . 17
5.5.4 Standard deviation and mean . 18
5.5.5 Optimum decision threshold . 18
5.5.6 BER optimum decision threshold . 18
5.5.7 BER non-optimum decision threshold . 19
5.5.8 Error bound . 19
5.6 Test documentation . 19
5.7 Specification information . 19
6 Variable optical threshold method . 19
6.1 Overview. 19
6.2 Apparatus . 20
6.3 Items under test . 20
6.4 Procedure for basic optical link . 20
6.5 Procedure for self-contained system . 21
6.6 Evaluation of results . 22
Annex A (normative) Calculation of error bound in the value of Q . 24
Annex B (informative) Sinusoidal interference method . 26
B.1 Overview. 26
B.2 Apparatus . 26
B.3 Sampling and specimens . 26
B.4 Procedure . 27
B.4.1 Optical sinusoidal interference method . 27
B.4.2 Electrical sinusoidal interference method . 28
B.5 Calculations and interpretation of results . 29
B.5.1 Mathematical analysis . 29
B.5.2 Extrapolation . 29
B.5.3 Expected results . 30
B.6 Documentation . 31

IEC 61280-2-8:2021 © IEC 2021 – 3 –
B.7 Specification information . 31
Bibliography . 32

Figure 1 – Sample eye diagram showing patterning effects . 9
Figure 2 – More accurate measurement technique using a DSO that samples noise
statistics between eye centres . 10
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 . 12
Figure 5 – Set-up for the variable decision threshold method . 14
Figure 6 – Set-up of initial threshold level (approximately at the centre of the eye) . 14
Figure 7 – Effect of optical bias . 20
Figure 8 – Set-up for optical link or device test . 21
Figure 9 – Set-up for system test . 21
Figure 10 – Extrapolation of log BER as a function of bias . 23
Figure B.1 – Set-up for the sinusoidal interference method by optical injection . 27
Figure B.2 – Set-up for the sinusoidal interference method by electrical injection . 29
Figure B.3 – BER result from the sinusoidal interference method (data points and
extrapolated line) . 30
Figure B.4 – BER versus optical power for three methods . 31

Table 1 – Mean time for the accumulation of 15 errors as a function of BER and bit rate . 7
Table 2 – BER as a function of threshold voltage . 16
Table 3 – f as a function of D . 17
i i
Table 4 – Values of linear regression constants . 18
Table 5 – Mean and standard deviation . 18
Table 6 – Example of optical bias test . 22
Table B.1 – Results for sinusoidal injection . 28

– 4 – IEC 61280-2-8:2021 © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
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FIBRE OPTIC COMMUNICATION SUBSYSTEM TEST PROCEDURES –

Part 2-8: Digital systems –
Determination of low BER using Q-fac
...