1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T L.13TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (04/2003) SERIES L: CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT Performance requirements for passive optical nodes: Sealed closures for outdoor environments IT
2、U-T Recommendation L.13 ITU-T Rec. L.13 (04/2003) i ITU-T Recommendation L.13 Performance requirements for passive optical nodes: Sealed closures for outdoor environments Summary This Recommendation refers to passive optical nodes in outdoor environments. It deals with the design of the closure hous
3、ing as well as the fibre organizer taking into account mechanical and environmental characteristics as well as the characteristics of the optical fibre organizer. The following elements are added for this revision: a test plan for the performance evaluation of sealed optical closures in 2 basic envi
4、ronments: underground (OS) or above ground (OA); the simulation of the effect of interventions related to network maintenance. Appendices were added: a checklist for a systematic product characterization according to L.51; a list of additional requirements to reflect special environments (e.g., tunn
5、els) or local conditions. Source ITU-T Recommendation L.13 was approved by ITU-T Study Group 6 (2001-2004) under the ITU-T Recommendation A.8 procedure on 11 April 2003. ii ITU-T Rec. L.13 (04/2003) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in
6、the field of telecommunications. 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 view to standardizing telecommunications on a worldwide basis.
7、 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 Recommendations is covered by the procedure laid down in WTSA Resoluti
8、on 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 conciseness to indicate both a telecommunication administration and
9、 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 is achieved when all of these mandatory provisions are met.
10、 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. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibil
11、ity 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, whether asserted by ITU members or others outside of the Reco
12、mmendation development process. As of the date of approval of this Recommendation, ITU had/had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest inform
13、ation and are therefore strongly urged to consult the TSB patent database. ITU 2003 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. L.13 (04/2003) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Terms
14、and definitions . 2 4 Abbreviations and acronyms 3 5 Design characteristics of optical closures. 3 5.1 General requirements 3 5.2 Design of the closure housing 3 5.3 Design of the organizer system 4 6 Performance evaluation test program . 5 7 Sample preparation . 5 Annex A Performance evaluation cri
15、teria. 6 A.1 Mechanical and tightness evaluation 6 A.2 Optical evaluation. 6 Annex B Performance test program for underground closures (OS) and above ground closure (OA) . 7 B.1 Mechanical evaluation 7 B.2 Optical evaluation. 10 Appendix I Product characterization checklist . 12 Appendix II Ukrainia
16、n experience 14 II.1 Introduction 14 II.2 Dimension and optical characteristics 14 II.3 Environmental characteristics 15 II.4 Mechanical characteristics 16 II.5 Field condition tests 18 iv ITU-T Rec. L.13 (04/2003) Introduction A node occurs at each opening or end of a cable sheath. When an optical
17、node resides in an outdoor environment, it is generally contained in a sealed enclosure. This is commonly also referred to as an optical closure, optical cable joint or optical sheath joint. In this Recommendation the term “optical closure“ will be used. An optical closure comprises a mechanical str
18、ucture (closure housing) that is attached to the ends of the sheaths joined and a means (organizer) for containing and protecting the fibres and passive optical devices. The optical closure will: restore the integrity of the sheath, including mechanical continuity of strength members when required;
19、protect the fibres, fibre joints and optical devices from the environment in all types of outdoor plant (aerial, direct buried, in ducts and underwater); provide for the organization of the fibre joints, passive devices and the storage of fibre overlength; provide electrical bonding and grounding of
20、 the metal parts of the sheath and strength members where required. The method of achieving electrical continuity will vary with the type of cable sheath and the type and location of the strength members. Further information is given in ITU-T Recs K.11, K.25 and ITU-T Manual “Protection of telecommu
21、nication lines and equipment against lightning discharges“. This Recommendation acknowledges that the cable sheaths used with optical fibre cables are of similar design to those used with copper cables. Thus, the methods used for jointing optical fibre cable sheaths are based on those used in sheath
22、 joints for conventional copper cable; reference may be made to the Handbook “Outside plant technologies for public networks“ and L-series Recommendations. Compared to the previous version, this Recommendation provides the means for characterization and evaluation of the performance of optical closu
23、res according to the principles of ITU-T Rec. L.51. This includes both mechanical integrity and optical stability of the product, simulating the effect of environmental factors, as well as interventions related to network maintenance. It contains a basic test program for optical closures which is gl
24、obally applicable. Additional requirements can be agreed upon between customer and supplier to reflect local or special conditions. All functions and features that a product may contain must be reflected in the mix of test samples that are subjected to the test program. ITU-T Rec. L.13 (04/2003) 1 I
25、TU-T Recommendation L.13 Performance requirements for passive optical nodes: Sealed closures for outdoor environments 1 Scope This Recommendation: refers to passive optical nodes in outdoor environments; deals with the design of the closure housing as well as the fibre organizer; deals with mechanic
26、al and environmental characteristics of the optical closure; deals with the characteristics of the optical fibre organizers. Following elements are added for this revision: a test plan for the performance evaluation of sealed optical closures in 2 basic environments: underground (OS) or above ground
27、 (OA); the simulation of the effect of interventions related to network maintenance; a checklist for a systematic product characterisation according to ITU-T Rec. L.51; a list of additional requirements to reflect special environments (e.g., tunnels) or local conditions. 2 References The following I
28、TU-T Recommendations 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 Recommendat
29、ion are therefore encouraged 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 i
30、t, as a stand-alone document, the status of a Recommendation. ITU-T Recommendation G.652 (2003), Characteristics of a single-mode optical fibre and cable. ITU-T Recommendation K.11 (1993), Principles of protection against overvoltages and overcurrents. ITU-T Recommendation K.25 (2000), Protection of
31、 optical fibre cables. ITU-T Recommendation L.51 (2003), Passive node elements for fibre optic networks General principles and definitions for characterization and performance evaluation. IEC 60068-2-6:1995, Environmental testing Part 2: Tests Test Fc: Vibration (sinusoidal). IEC 60068-2-11:1981, En
32、vironmental testing Part 2: Tests. Test Ka: Salt mist. IEC 60068-2-14:1984, Environmental testing Part 2: Tests. Test N: Change of temperature. IEC 60068-2-17:1994, Basic environmental testing procedures Part 2: Tests Test Q: Sealing. IEC 60068-2-27:1987, Environmental testing. Part 2: Tests. Test E
33、a and guidance: Shock. IEC 60529:2001, Degrees of protection provided by enclosures (IP Code). 2 ITU-T Rec. L.13 (04/2003) IEC 61300-2-1:2003, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-1: Tests Vibration (sinusoidal). IEC 61300-2-4:1995,
34、Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-4: Tests Fibre/cable retention. IEC 61300-2-5:2002, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-5: Tests Torsion/twist. IEC 61300-2-9:19
35、95, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-9: Tests Shock. IEC 61300-2-10:1995, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-10: Tests Crush resistance. IEC 61300-2-12:1995, Fi
36、bre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-12: Tests Impact. IEC 61300-2-22:1995, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-22: Tests Change of temperature. IEC 61300-2-23:1995, F
37、ibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-23: Tests Sealing for non-pressurized closures of fibre optic devices. IEC 61300-2-26:1995, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-2
38、6: Tests Salt mist. IEC 61300-2-33:1995, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-33: Tests Assembly and disassembly of closures. IEC 61300-2-34:1995, Fibre optic interconnecting devices and passive components Basic test and measurement
39、procedures Part 2-34: Tests Resistance to solvents and contamining fluids. IEC 61300-2-37:1995, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 2-37: Tests Cable bending for closures. IEC 61300-2-38:1995, Fibre optic interconnecting devices and p
40、assive components Basic test and measurement procedures Part 2-38: Tests Sealing for pressurized closures of fibre optic devices. IEC 61300-3-1:1995, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 3-1: Examinations and measurements Visual examin
41、ation. IEC 61300-3-3:2003, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 3-3: Examinations and measurements Active monitoring changes in attenuation and return loss (multiple paths). IEC 61300-3-28:2002, Fibre optic interconnecting devices and
42、passive components Basic test and measurement procedures Part 3-28: Examinations and measurements Transient loss. 3 Terms and definitions This Recommendation defines the following terms: 3.1 optical closure: The term “optical closure“ refers to a sealed sheath joint, including the fibre organizer sy
43、stem. ITU-T Rec. L.13 (04/2003) 3 3.2 closure housing: Closure housing only refers to the sealed container or box, not including the organizer system. Its main functions are: sealing to the cables, mechanical attachment of the cable and protection of its content. 3.3 organizer system: In a node, the
44、 optical fibres are to be properly managed and guided from where a cable or pigtail enters the node, until it leaves again. The organizer system comprises the whole of means and features that are intended to guide and store fibres and passive devices inside a node, at any location where they are not
45、 protected by the cable sheath. 4 Abbreviations and acronyms For the definitions of terms used in this Recommendation, see ITU-T Rec. L.51. CM Central strength Member ME Multiple Element (mass storage) OA Outdoor Above Ground OS Outdoor Subterranean or underground SC Single Circuit SE Single Element
46、 SF Single Fibre SR Single Ribbon 5 Design characteristics of optical closures 5.1 General requirements Each optical closure must comply to the general requirements as listed in clause 8/L.51. 5.2 Design of the closure housing Closure housing designs employ either cold or hot systems depending on th
47、e sealing methods used. Cold processes do not require heat, whereas hot processes do. Mastic, tapes, grommets, o-rings, cured rubber shapes, pastes, potting compounds, rubber gels and (cold) adhesives are cold processes. Thermoshrinkable materials, hotmelts and polyethylene injection welding are the
48、 primary hot processes. The heat source may be electrical resistance heating, infrared heating, hot air, or a gas flame. Regardless of which of these processes is used, the following shall be considered: the materials used for making the cable joint shall be compatible with each other, with the mate
49、rials of the sheath and with other materials normally used in the outside plant; a design may allow for jointing together two or more cable ends. The cables entering the closure may be of differing sizes and/or types; a design should allow for jointing together at least one pair of cables which are not at the end of a cable i.e., without cutting all the fibres between both cable ends
