1、 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 IEC 61280-2-1:2010(E) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2010 IEC, Geneva, Switzerland All rights reser
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9、TANDARD Fibre optic communication subsystem test procedures Part 2-1: Digital systems Receiver sensitivity and overload measurement INTERNATIONAL ELECTROTECHNICAL COMMISSION N ICS 33.180.01 PRICE CODE ISBN 2-8318-1084-2 Registered trademark of the International Electrotechnical Commission 2 61280-2-
10、1 IEC:2010(E) CONTENTS FOREWORD.3 1 Scope and object5 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 in
11、terface.7 4 Equipment under test (EUT) .8 5 Test procedure .8 5.1 Operating conditions and test environment8 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 determination10 5.4 Measurement of overload level11 5.4.1 P
12、ower level calibration.11 5.4.2 Overload level determination .12 5.4.3 Calculation of overload level12 6 Measurement uncertainties.13 7 Test results 13 7.1 Required information .13 7.2 Available information.13 Bibliography14 Figure 1 Optical fibre system .5 Figure 2 Setup for the measurement of inpu
13、t 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 terminal11 Figure 5 Setup for the measurement of overload level for an amplifier or regenerator 12 Table 1
14、 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 o
15、rganization 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 activiti
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24、ions. 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 pat
25、ent 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 f
26、irst 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 “t
27、est 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 stan
28、dard 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 foun
29、d 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, withdra
30、wn, 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 IE
31、C 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 specifi
32、ed 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 regenerat
33、ors 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 char
34、acteristics of the optical input interface of the receiver, amplifier or regenerator shown. Measurement Point Optical Fibre Link System Output Optical Receive Interface Receive Equipment System Input Optical Transmit Interface Transmit Equipment Optical Amplifier/ Regen. Optical Fibre Link Optical F
35、ibre Link Optical Receive Interface Receive Equipment System Output System Input Optical Transmit Interface Transmit Equipment Optical Amplifier/ Regen. Optical Fibre Link Measurement Point Measurement Point Optical Fibre Link Optical Fibre Link System Output Optical Receive Interface Receive Equipm
36、ent System Output System Output Optical Receive Interface Receive Equipment Optical Receive Interface Optical Receive Interface Receive Equipment System Input Optical Transmit Interface Transmit Equipment System Input System Input Optical Transmit Interface Transmit Equipment Optical Transmit Interf
37、ace Transmit Equipment Optical Amplifier/ Regen. Optical Amplifier/ Regen. Optical Fibre Link Optical Fibre Link Optical Fibre Link Optical Receive Interface Receive Equipment System Output System Input Optical Transmit Interface Transmit Equipment Optical Amplifier/ Regen. Optical Fibre Link Optica
38、l Fibre Link Optical Fibre Link Optical Receive Interface Receive Equipment System Output Optical Receive Interface Receive Equipment Optical Receive Interface Optical Receive Interface Receive Equipment System Output System Output System Input Optical Transmit Interface Transmit Equipment System In
39、put System Input Optical Transmit Interface Transmit Equipment Optical Amplifier/ Regen. Optical Amplifier/ Regen. Optical Fibre Link Optical Fibre Link Measurement PointFigure 1 Optical fibre system It should be noted that the performance of fibre optic receivers may differ for different signal for
40、mats. It is therefore necessary to use the signal format that represents actual operating conditions. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. IEC 469/10 6 61280-2-1 IEC:2010(E) 2.1 bit error ratio (BER) the number of errored bits divided
41、by the total number of bits, over some stipulated period of time IEC 61931, definition 2.9.33 2.2 bit sequence a defined sequence of ones (1) and zeros (0) in a digital signal 2.3 bit pattern a predetermined sequence of 1s and 0s in a digital signal which is repeated at regular intervals 2.4 errored
42、 block ratio (EBR) the number of errored blocks, containing a defined number of digits, divided by the total number of blocks received in a specified period of time. An errored block may contain more than one errored bit 2.5 overload level the maximum input power above which a specified quality of p
43、erformance is no longer achieved 2.6 pseudo random binary sequence (PRBS) a repeated bit sequence which simulates a random pattern of 1s and 0s. It is generated by the addition of the r thpreceding digit of a sequence of n bits and eliminating the sequence of n 0s (or n 1s). The pattern repeats afte
44、r 2 n -1 bits 2.7 receiver sensitivity the minimum power required to achieve a specified quality of performance IEC 61931, definition 2.7.58, modified 2.8 system input and output signals for the purpose of this specification, the system input and output are defined as signals which interface with ex
45、ternal equipment. These signals have specified formats specific to the application and may be electrical or optical. The signals are accessed via physical interfaces that are specific to the equipment 3 Apparatus 3.1 General The test setup is shown in Figure 2. It is important that test cords 3 and
46、4 are of a similar type and make and are of equal length. 3.2 BER test set The BER test set is made up of the elements described here. 61280-2-1 IEC:2010(E) 7 3.2.1 Data generator The data generator of the BER test set shall be capable of providing a data input to the system which may be a pseudo-ra
47、ndom sequence or otherwise specified bit pattern with the signal format (pulse shape, amplitude, etc.) that is consistent with the requirements at the system input interface of the EUT. As a minimum requirement the data generator shall be capable of providing the following output date formats; other
48、 data formats may be used in compliance with the system requirements. a 2 23 -1 pseudo-random data stream; an all 1 data stream; a 1 + 15 zeros data stream. The format (pulse shape, amplitude, etc.) of the test signal shall be compliant with that required at the transmit input interface. The receive
49、r portion of the test equipment shall be able to interface with the system output for the measurement of digital errors. 3.2.2 Error counter The error counter of the BER test set shall be able to interface with the output of the EUT. It shall be capable counting single errors or errored blocks at the data rate of system output interface of the EUT. If the error counter has the facility for computing the BER or EBR value it must be capable of calculating a valu
