1、 International Telecommunication Union ITU-T G.655TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2009) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Transmission media and optical systems characteristics Optical fibre cables Characteristics of a non-zero dispersion-shif
2、ted single-mode optical fibre and cable Recommendation ITU-T G.655 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS G.200
3、G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AND LINE TEL
4、EPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 General G.600G.609 Symmetric cable pairs G.610G.619 Land coaxial cable pairs G.620G.629 Submarine cables G.630G.639 Free space optical systems G.640G.649 Optical fibre cables G.650G.659Characteristics of optical comp
5、onents and subsystems G.660G.679 Characteristics of optical systems G.680G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSI
6、ON MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.655 (11/2009) i Recommendation ITU-T G.655 Characteristi
7、cs of a non-zero dispersion-shifted single-mode optical fibre and cable Summary This Recommendation describes the geometrical, mechanical, and transmission attributes of a single-mode optical fibre which has the absolute value of the chromatic dispersion coefficient greater than some non-zero value
8、throughout the wavelength range from 1530 nm to 1565 nm. This dispersion reduces the growth of non-linear effects which are particularly deleterious in dense wavelength division multiplexing systems. The last revision in 2006 adds two new categories of this fibre in Tables D and E. Both of these cat
9、egories limit the chromatic dispersion coefficient by a pair of bounding curves versus wavelength for the range of 1460 nm to 1625 nm. Although the dispersion can change sign at wavelengths less than 1530 nm, the inclusion of these lower wavelengths is intended to provide information to support coar
10、se wavelength division multiplexing applications which do not have significant non-linear impairments, at channels from 1471 nm and higher. These tables are introduced to distinguish the two main families of ITU-T G.655 fibres that are supported by multiple vendors. Table 1, “G.655.A attributes“, Ta
11、ble 2, “G.655.B attributes“, and Table 3, “G.655.C attributes“, of the 2003 edition have not been changed, of which, only the G.655.C attributes table is included in this current edition. This is the latest revision of a Recommendation that was first created in 1996. This revision adds a new note in
12、 the G.655.C, G.655.D and G.655.E attributes tables, allowing higher maximum cabled attenuation for short cables. Jumper cable cut-off wavelength is deleted as well. This revision is expected to improve harmonization with IEC standards. Source Recommendation ITU-T G.655 was approved on 13 November 2
13、009 by ITU-T Study Group 15 (2009-2012) under Recommendation ITU-T A.8 procedures. ii Rec. ITU-T G.655 (11/2009) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). Th
14、e ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standa
15、rdization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information
16、technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Com
17、pliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other o
18、bligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implement
19、ation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As
20、 of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to
21、consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.655 (11/2009) iii CONTENTS Page 1 Scope 1 2 References. 2 3 Terms and defin
22、itions . 2 4 Abbreviations 2 5 Fibre attributes 2 5.1 Mode field diameter . 3 5.2 Cladding diameter 3 5.3 Core concentricity error 3 5.4 Non-circularity . 3 5.5 Cut-off wavelength . 3 5.6 Macrobending loss 3 5.7 Material properties of the fibre . 4 5.8 Refractive index profile 4 5.9 Longitudinal uni
23、formity of chromatic dispersion . 4 5.10 Chromatic dispersion coefficient 4 6 Cable attributes . 5 6.1 Attenuation coefficient . 5 6.2 Polarization mode dispersion (PMD) coefficient . 6 7 Tables of recommended values 6 Appendix I Information for link attributes and system design . 11 I.1 Attenuation
24、 . 11 I.2 Chromatic dispersion 11 I.3 Differential group delay (DGD) . 12 I.4 Non-linear coefficient . 12 I.5 Tables of common typical values . 12 I.6 Examples of implementation 13 I.7 Chromatic dispersion coefficient limits for Tables 2 and 3 . 13 Bibliography. 17 iv Rec. ITU-T G.655 (11/2009) Intr
25、oduction The following paragraphs provide a summary of the evolution of Recommendation ITU-T G.655, from its first 1996 version to the latest 2009 edition. 1996 Edition 1.0. 2000 Edition 2.0. This revision includes the addition of tables for different levels of system support. 2003 Edition 3.0. In a
26、ccordance with the agreement on spectral bands, the description of the L band upper limit is changed from 16xx to 1625 nm. Terms of base subcategory and subcategory are revised to base category and category, respectively. PMD requirements are added for all categories and two categories have reduced
27、limits (compared to 0.5 ps/km). For the macrobending test, mandrel diameter is reduced to 30 mm radius. As seen above, this Recommendation has evolved considerably over the years; therefore, the reader is warned to consider the appropriate version to determine the characteristics of an already deplo
28、yed product, taking into account the year of production. In fact, products are expected to comply with the Recommendation that was in force at the time of their manufacture, but may not fully comply with subsequent versions of the Recommendation. 2006 Edition 4.0. This revision adds two new categori
29、es of this fibre in Tables D and E. Both of these categories limit the chromatic dispersion coefficient by a pair of bounding curves versus wavelength for the range of 1460 nm to 1625 nm. Although the dispersion can change sign at wavelengths less than 1530 nm, the inclusion of these lower wavelengt
30、hs is intended to provide information to support coarse wavelength division multiplexing applications which do not have significant non-linear impairments, at channels from 1471 nm and higher. These tables are introduced to distinguish the two main families of G.655 fibres that are supported by mult
31、iple vendors. Tables A, B, and C have not been changed. Tables A and B are not included in this version of this Recommendation, but are in the 2003 edition. 2009 Edition 5.0. IEC 60794-2-11 (2005) is added as one of the Informative references. The tables have been renumbered. Tables 1, 2, and 3 of e
32、dition 5.0 correspond, respectively, to Tables 3, 4, and 5 of edition 4.0. Uncabled fibre PMD coefficient requirements have been added in Tables 2 and 3. A new note has been introduced in Tables 1 to 3, to allow higher maximum cabled attenuation for short cables. Rec. ITU-T G.655 (11/2009) 1 Recomme
33、ndation ITU-T G.655 Characteristics of a non-zero dispersion-shifted single-mode optical fibre and cable 1 Scope This Recommendation describes a single-mode fibre with a chromatic dispersion coefficient (absolute value) that is greater than some non-zero value throughout the wavelengths larger than
34、1530 nm. This dispersion reduces the growth of non-linear effects that can be particularly deleterious in dense wavelength division multiplexing (DWDM) systems. At lower wavelengths, the dispersion coefficient can cross zero, but chromatic dispersion coefficient values at these wavelengths may be sp
35、ecified to support coarse wavelength division multiplexing (CWDM) systems that do not have significant impairments due to non-linear effects. These fibres were originally intended for use at wavelengths in a prescribed region between 1530 nm and 1565 nm. Provisions have been made to support transmis
36、sion at higher wavelengths of up to 1625 nm and lower wavelengths down to 1460 nm. In clause 7, Tables 2 and 3 distinguish the two main families of ITU-T G.655 fibre implementations that are supported by multiple vendors. The G.655.A, G.655.B and G.655.C attributes tables can be used to define other
37、 implementations. The G.655.A and G.655.B attributes tables of the 2003 edition are not included in the current version of this Recommendation. The geometrical, optical, transmission and mechanical parameters are described below in three categories of attributes: fibre attributes are those attribute
38、s that are retained throughout cabling and installation; cable attributes that are recommended for cables as they are delivered; link attributes that are characteristics of concatenated cables, describing estimation methods of system interface parameters based on measurements, modelling, or other co
39、nsiderations. Information for link attributes and system design are in Appendix I. This Recommendation, and the different performance categories found in the tables of clause 7, is intended to support the following related system Recommendations: ITU-T G.691; ITU-T G.692; ITU-T G.693; ITU-T G.695; I
40、TU-T G.696.1; ITU-T G.698.1; ITU-T G.957; ITU-T G.959.1. This Recommendation contains a combination of fibre designs able to cover a broad spectrum of applications. Some re-arrangement might be considered in the future. However, the system compatibility of fibres with different characteristics is no
41、t proved and, in general, their simultaneous use in one system might be questioned and should be agreed in advance between the user and manufacturers. The meaning of the terms used in this Recommendation and the guidelines to be followed in the measurement to verify the various characteristics are g
42、iven in ITU-T G.650.1 and ITU-T G.650.2. The characteristics of this fibre, including the definitions of the relevant 2 Rec. ITU-T G.655 (11/2009) parameters, their test methods and relevant values, will be refined as studies and experience progress. 2 References The following ITU-T Recommendations
43、and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore enc
44、ouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone d
45、ocument, the status of a Recommendation. ITU-T G.650.1 Recommendation ITU-T G.650.1 (2004), Definitions and test methods for linear, deterministic attributes of single-mode fibre and cable. ITU-T G.650.2 Recommendation ITU-T G.650.2 (2007), Definitions and test methods for statistical and non-linear
46、 related attributes of single-mode fibre and cable. 3 Terms and definitions For the purposes of this Recommendation, the definitions given in ITU-T G.650.1 and ITU-T G.650.2 apply. Values shall be rounded to the number of digits given in the tables of recommended values before conformance is evaluat
47、ed. 4 Abbreviations This Recommendation uses the following abbreviations: AeffEffective area CWDM Coarse Wavelength Division Multiplexing DGD Differential Group Delay DWDM Dense Wavelength Division Multiplexing GPa GigaPascal PMD Polarization Mode Dispersion PMDQStatistical Parameter for PMD link SD
48、H Synchronous Digital Hierarchy TBD To Be Determined WDM Wavelength Division Multiplexing 5 Fibre attributes Only those characteristics of the fibre providing a minimum essential design framework for fibre manufacturers are recommended in this clause. Ranges or limits on values are presented in the
49、tables of clause 7. Of these, cable manufacture or installation may significantly affect the cabled fibre cut-off wavelength and PMD. Otherwise, the recommended characteristics will apply equally to individual fibres, fibres incorporated into a cable wound on a drum, and fibres in an installed cable. Rec. ITU-T G.655 (11/2009) 3 5.1 Mode field diameter Both a nominal value and tolerance about that nominal value shall be specified at 1550 nm. The nominal that is specified shall be within the range found in clau
