IEC 61280-2-1:2010

IEC 61280-2-1 ®
Edition 2.0 2010-03
INTERNATIONAL
STANDARD
Fibre optic communication subsystem test procedures –
Part 2-1: Digital systems – Receiver sensitivity and overload measurement

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: inmail@iec.ch
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) 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, a corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
ƒ IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
ƒ Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
ƒ Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: csc@iec.ch
Tel.: +41 22 919 02 11
Fax: +41 22 919 03 00
IEC 61280-2-1 ®
Edition 2.0 2010-03
INTERNATIONAL
STANDARD
Fibre optic communication subsystem test procedures –
Part 2-1: Digital systems – Receiver sensitivity and overload measurement

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
N
ICS 33.180.01 ISBN 978-2-88910-474-1
– 2 – 61280-2-1 © IEC:2010(E)
CONTENTS
FOREWORD.3
1 Scope and object.5
2 Terms and definitions .5
3 Apparatus.6
3.1 General .6
3.2 BER test set .6
3.2.1 Data generator .7
3.2.2 Error counter .7
3.3 Optical power meter .7
3.4 Variable optical attenuator.7
3.5 Optical splitter .7
3.6 Test cords .7
3.7 Optical transmit interface.7
4 Equipment under test (EUT) .8
5 Test procedure .8
5.1 Operating conditions and test environment.8
5.2 Connector end-face cleaning.8
5.3 Measurement of input sensitivity .8
5.3.1 Optical input power calibration.10
5.3.2 BER or EBR determination.10
5.4 Measurement of overload level.11
5.4.1 Power level calibration.11
5.4.2 Overload level determination .12
5.4.3 Calculation of overload level.12
6 Measurement uncertainties.13
7 Test results .13
7.1 Required information .13
7.2 Available information.13
Bibliography.14

Figure 1 – Optical fibre system .5
Figure 2 – Setup for the measurement of input sensitivity of a receive terminal.9
Figure 3 – Setup for the measurement of input sensitivity of an amplifier or regenerator .9
Figure 4 – Setup for the measurement of overload level for a receive terminal.11
Figure 5 – Setup for the measurement of overload level for an amplifier or regenerator .12

Table 1 – Minimum monitoring time.10

61280-2-1 © IEC:2010(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE OPTIC COMMUNICATION SUBSYSTEM
TEST PROCEDURES –
Part 2-1: Digital systems –
Receiver sensitivity and overload measurement

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of 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 IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61280-2-1 has been prepared by subcommittee 86C: Fibre optic
systems and active devices, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition, published in 1998, and constitutes
a technical revision.
The main changes with respect to the previous edition are listed below:
– revised to include the requirements associated with data communication equipment,
regenerators and amplifiers;
– the term “jumper lead” has been replaced by “test cord”:
– a section for definitions has been added;
– a section on measurement uncertainties has been added.

– 4 – 61280-2-1 © IEC:2010(E)
The text of this standard is based on the following documents:
CDV Report on voting
86C/881/CDV 86C/945/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 61280 series, published under the general title Fibre optic
communication subsystem test procedures, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

61280-2-1 © IEC:2010(E) – 5 –
FIBRE OPTIC COMMUNICATION SUBSYSTEM
TEST PROCEDURES –
Part 2-1: Digital systems –
Receiver sensitivity and overload measurement

1 Scope and object
This part of IEC 61280 describes the test procedures applicable to digital fibre optic
communication and data systems.
The object of this test procedure is to measure the minimum and maximum optical powers
required and allowed at the optical input port of a fibre optic system to ensure its operation
within specified limits. Another objective is to verify that the guaranteed error performance is
obtained at the minimum and the maximum optical input powers specified by the terminal
equipment manufacturer.
Figure 1 shows the typical elements associated with optical fibre systems. Optical amplifiers
or regenerators may be used in long haul telecom systems, but are not usually associated
with data transport systems such as Ethernet, etc. In bi-directional systems the transmitter
and corresponding receiver are usually co-located, as indicated by the dotted lines. This
specification is concerned with the characteristics of the optical input interface of the receiver,
amplifier or regenerator shown.
OpOpOpOpOpOpticticticticticticaaaaaallllll OOOOptptptptiiiicacacacallll Fi Fi Fi Fibbbbrrrre Lie Lie Lie Linnnnkkkk OpOpOpOpticticticticaaaallll OOOOptptptptiiiicacacacallll Fi Fi Fi Fibbbbrrrre Lie Lie Lie Linnnnkkkk
OpOpOpOpticticticticaaaallll
ReReReReReRecccccceeeeeeiiiiiivvvvvveeeeee AmAmAmAmpppplllliiiiffffiiiieeeerrrr////
TrTrTrTransansansansmmmmiiiitttt
InInInInInInteteteteteterrrrrrfafafafafafacccccceeeeee ReReReReggggeeeennnn.
SSSSSystystystystysteeeeemmmmm InInInInteteteterrrrfafafafacccceeee
SSSSSystystystystysteeeeemmmmm
OOOOOuuuuutttttputputputputput
IIIIInpunpunpunpunputtttt
RecRecRecRecReceieieieieivvvvveeeee
TTTTrrrransansansansmmmmiiiitttt
EEEEEquiquiquiquiquipppppmmmmmeeeeentntntntnt
EEEEquiquiquiquippppmmmmeeeentntntnt
OOOptptptiiicacacalll Fi Fi Fibbbrrre Lie Lie Linnnkkk OOOptptptiiicacacalll Fi Fi Fibbbrrre Lie Lie Linnnkkk
OpOpOpOpticticticticaaaallll OpOpOpticticticaaalll OpOpOpOpOpticticticticticaaaaalllll
TrTrTrTransansansansmmmmiiiitttt AmAmAmpppllliiifffiiieeerrr///
ReReReReReccccceeeeeiiiiivvvvveeeee
InInInInteteteterrrrfafafafacccceeee ReReRegggeeennn. InInInInInteteteteterrrrrfafafafafaccccceeeee
SSSSystystystysteeeemmmm SSSSystystystysteeeemmmm
OOOOuuuuttttputputputput
IIIInpunpunpunputttt
TTTTrrrransansansansmmmmitititit RecRecRecReceiveiveiveiveeee
EEEEquiquiquiquippppmmmmeeee
...