1、 International Telecommunication Union ITU-T L.59TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2008) SERIES L: CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT Optical fibre cables for indoor applications Recommendation ITU-T L.59 Rec. ITU-T L.59 (01/2008
2、) i Recommendation ITU-T L.59 Optical fibre cables for indoor applications Summary Recommendation ITU-T L.59 describes characteristics, construction and test methods for optical fibre cables for indoor applications. In order for an optical fibre to perform appropriately, characteristics that a cable
3、 should have are described. Also, the method of determining whether or not the cable has the required characteristics is described. Required conditions may differ according to the installation environment; detailed test conditions need to be agreed upon between a user and a manufacturer for the envi
4、ronment where a cable is to be used. Source Recommendation ITU-T L.59 was approved on 8 January 2008 by ITU-T Study Group 6 (2005-2008) under Recommendation ITU-T A.8 procedure. ii Rec. ITU-T L.59 (01/2008) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized ag
5、ency in the field of telecommunications, information and communication technologies (ICTs). The 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 vie
6、w to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization 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 Recommendat
7、ions is covered by the procedure laid down in WTSA Resolution 1. In some areas of information 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 concisen
8、ess to indicate both a telecommunication administration and a recognized operating agency. Compliance 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
9、is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory 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. INTEL
10、LECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation 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, wh
11、ether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are
12、cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2009 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission
13、 of ITU. Rec. ITU-T L.59 (01/2008) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Terms and definitions . 3 4 Abbreviations and acronyms 3 5 Characteristics of optical fibres and cables 3 5.1 Optical fibre characteristics 3 5.2 Mechanical characteristics 4 5.3 Environmental conditions. 5 5.4 Fire saf
14、ety . 6 6 Cable construction 6 6.1 Fibre coatings . 6 6.2 Cable element . 7 6.3 Sheath . 8 6.4 Identification of cable. 8 7 Test methods. 8 7.1 Test methods for cable element 8 7.2 Test methods for mechanical characteristics of the cable 9 7.3 Test methods for environmental characteristics. 11 7.4 T
15、est methods for fire safety 11 Appendix I Overview on IEC specifications for indoor optical fibre cable . 12 Appendix II Indoor cable pathway (Japanese experience) Indoor pathway systems for optical fibre cables 13 II.1 General . 13 II.2 Vertical cable pathway systems 13 II.3 Horizontal cable pathwa
16、y systems . 14 II.4 Pathway systems facilities 16 Appendix III Indoor cable specification (Chinese experience) 23 III.1 Fibre attenuation. 23 III.2 Mechanical characteristics 23 III.3 Environmental conditions. 24 III.4 Test methods for mechanical characteristics of the cable 24 III.5 Test methods fo
17、r environmental characteristics. 25 Bibliography. 26 Rec. ITU-T L.59 (01/2008) 1 Recommendation ITU-T L.59 Optical fibre cables for indoor applications 1 Scope This Recommendation: refers to multimode graded index and single-mode optical fibre cables to be used for telecommunication networks within
18、buildings; deals with mechanical and environmental characteristics of the optical fibre cables concerned. The optical fibre dimensional and transmission characteristics, together with their test methods, should comply with ITU-T G.652, ITU-T G.653, ITU-T G.654, ITU-T G.655, ITU-T G.656 and ITU-T G.6
19、57, which describe single-mode optical fibres, and ITU-T G.651.1 and IEC 60793-2-10, which describe multimode graded index optical fibres; deals with fundamental considerations related to optical fibre cable from mechanical and environmental aspects; acknowledges that some optical fibre cables may c
20、ontain metallic elements, for which reference should be made to b-ITU-T handbook (see ITU-T L.1), and other ITU-T L-series Recommendations; recommends that an optical fibre cable should be provided with cable end-sealing and protection during cable delivery and storage, as is common for metallic cab
21、les. If splicing components have been factory-installed, they should be adequately protected; recommends that pulling devices may be fitted to the end of the cable if required. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this t
22、ext, 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 encouraged to investigate the possibility of applying the most recent edition
23、 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 document, the status of a Recommendation. ITU-T G.650.1 Recommendation ITU-
24、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 related attributes of single-mode fibre and cable. ITU-T G.651.1 Recommen
25、dation ITU-T G.651.1 (2007), Characteristics of a 50/125 m multimode graded index optical fibre cable for the optical access network. ITU-T G.652 Recommendation ITU-T G.652 (2005), Characteristics of a single-mode optical fibre and cable. ITU-T G.653 Recommendation ITU-T G.653 (2006), Characteristic
26、s of a dispersion-shifted single-mode optical fibre and cable. ITU-T G.654 Recommendation ITU-T G.654 (2006), Characteristics of a cut-off shifted single-mode optical fibre and cable. 2 Rec. ITU-T L.59 (01/2008) ITU-T G.655 Recommendation ITU-T G.655 (2006), Characteristics of a non-zero dipersion-s
27、hifted single-mode optical fibre and cable. ITU-T G.656 Recommendation ITU-T G.656 (2006), Characteristics of a fibre and cable with non-zero dispersion for wideband optical transport. ITU-T G.657 Recommendation ITU-T G.657 (2006), Characteristics of a bending loss insensitive single mode optical fi
28、bre and cable for the access network. ITU-T L.1 Recommendation ITU-T L.1 (1988), Construction, installation and protection of telecommunication cables in public networks. ITU-T L.46 Recommendation ITU-T L.46 (2000), Protection of telecommunication cables and plant from biological attack. IEC 60189-1
29、 IEC 60189-1 (2007), Low-frequency cables and wires with PVC insulation and PVC sheath Part 1: General test and measuring method. IEC 60189-2 IEC 60189-2 (2007), Low-frequency cables and wires with PVC insulation and PVC sheath Part 2: Cables in pairs, triples, quads and quintuples for inside instal
30、lations. IEC 60189-3 IEC 60189-3 (2007), Low-frequency cables and wires with PVC insulation and PVC sheath Part 3: Equipment wires with solid or stranded conductor wires, PVC insulated, in singles, pairs and triples. IEC 60332-1-1 IEC 60332-1-1 (2004), Tests on electric and optical fibre cables unde
31、r fire conditions Part 1-1: Test for vertical flame propogation for a single insulated wire or cable Apparatus. IEC 60332-3-24 IEC 60332-3-24 (2000), Tests on electric cables under fire conditions Part 3-24 : Test for vertical flame spread of vertically-mounted bunched wires or cables Category C. IE
32、C 60754-1 IEC 60754-1 (1994), Test on gases evolved during combustion of materials from cables Part 1: Determination of the amount of halogen acid gas. IEC 60754-2 IEC 60754-2 (1991), Test on gases evolved during combustion of electric cables Part 2: Determination of degree of acidity of gases evolv
33、ed during the combustion of materials taken from electric cables by measuring pH and conductivity. IEC 60793-1-1 IEC 60793-1-1 (2002), Optical fibres Part 1-1: Measurement methods and test procedures General and guidance. IEC 60793-1-21 IEC 60793-1-21 (2001), Optical fibres Part 1-21: Measurement me
34、thods and test procedures Coating geometry. IEC 60793-1-32 IEC 60793-1-32 (2001), Optical fibres Part 1-32: Measurement methods and test procedures Coating strippability. Rec. ITU-T L.59 (01/2008) 3 IEC 60793-2-10 IEC 60793-2-10 (2007), Optical fibres Part 2-10: Product specifications Sectional spec
35、ification for category A1 multimode fibres. IEC 60794-1-1 IEC 60794-1-1 (2001), Optical fibre cables Part 1-1: Generic specification General. IEC 60794-1-2 IEC 60794-1-2 (2003), Optical fibre cables Part 1-2: Generic specification Basic optical cable test procedures. IEC 60794-2 IEC 60794-2 (2002),
36、Optical fibre cables Part 2: Indoor cables Sectional specification. IEC 60794-2-20 IEC 60794-2-20 (2003), Optical fibre cables Part 2-20: Indoor cables Family specification for multi-fibre optical distribution cables. IEC 60794-3 IEC 60794-3 (2001), Optical fibre cables Part 3: Sectional specificati
37、on Outdoor cables. IEC 61034-1 IEC 61034-1 (2005), Measurement of smoke density of cables burning under defined conditions Part 1: Test apparatus. IEC 61034-2 IEC 61034-2 (2005), Measurement of smoke density of cables burning under defined conditions Part 2: Test procedure and requirements. 3 Terms
38、and definitions For the purpose of this Recommendation, the definitions given in ITU-T G.650.1 and ITU-T G.650.2 apply. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: D Used to denote the diameter of the cable H Used to denote the height of the cable
39、SZ Reverse oscillating stranding TALower bound for temperature range TBUpper bound for temperature range UV Ultraviolet ray 5 Characteristics of optical fibres and cables 5.1 Optical fibre characteristics Optical fibres described in ITU-T G.651.1, ITU-T G.652, ITU-T G.653, ITU-T G.654, ITU-T G.655,
40、ITU-T G.656, ITU-T G.657 or IEC 60793-2-10 should be used depending upon users environmental conditions and technical requirements. 4 Rec. ITU-T L.59 (01/2008) 5.1.1 Transmission characteristics The typical transmission characteristics are described in the appropriate Recommendations on optical fibr
41、es. 5.1.2 Fibre microbending Severe bending of an optical fibre, involving local axial displacement of a few micrometres over short distances caused by localized lateral forces along its length, is called microbending. This may be caused by manufacturing and installation strains and also dimensional
42、 variations of cable materials due to temperature changes during its lifetime. Microbending can cause an increase in optical loss. In order to reduce microbending loss, stresses applied to a fibre randomly and longitudinally should be eliminated when manufacturing, installing and utilizing the cable
43、. 5.1.3 Fibre macrobending Macrobending is the resulting curvature of an optical fibre after cable manufacture and installation. Macrobending may cause an increase in optical loss. The optical loss increases if the bending radius is lower than a minimum established limit. 5.1.4 Fibre attenuation Max
44、imum allowable attenuations are described in each Recommendation of optical fibres. However, if there is a different agreement between a manufacturer and a user, higher values can be allowed. 5.2 Mechanical characteristics 5.2.1 Tensile strength Optical fibre cable is subject to short-term load duri
45、ng manufacture and installation, and may be affected by continuous static loading and/or cyclic load during operation (e.g., temperature variation). Changes in the tension of the cable due to the variety of factors encountered during the service life of the cable can cause differential movement of t
46、he cable components. This effect needs to be considered in the cable design. Excessive cable tensile load may increase optical loss and may cause increased residual strain in the fibre if the cable cannot relax. To avoid this, the maximum tensile strength determined by the cable construction, especi
47、ally the design of the strength member, should not be exceeded. Therefore, when designing a tensile member, an agreement between a manufacturer and a user on maximum tensile load during storage, installation and operation is required. NOTE Where a cable is subject to permanent load during its operat
48、ional life, it is preferable that the fibre does not experience additional strain. 5.2.2 Bending Under the dynamic conditions encountered during installation, optical fibre is subject to strain from both cable tension and bending. The strength elements in the cable and the installation bend radius m
49、ust be selected to limit this combined dynamic strain. Any fibre bend radius remaining after cable installation shall be large enough to limit the macrobending loss or long-term strain reducing the lifetime of the fibre. The bending test should be performed according to clause 7.2.2. After the test, there shall be no fibre breakage. Rec. ITU-T L.59 (01/2008) 5 5.2.3 Crush The cable may be subject to crush during bo
