1、 International Telecommunication Union ITU-T L.35TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1(11/2007) SERIES L: CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT Installation of optical fibre cables in the access network Amendment 1: New Appendix
2、 II Korean experience with access network installation procedures ITU-T Recommendation L.35 (1998) Amendment 1 ITU-T Rec. L.35 (1998)/Amd.1 (11/2007) i ITU-T Recommendation L.35 Installation of optical fibre cables in the access network Amendment 1 New Appendix II Korean experience with access netwo
3、rk installation procedures Summary This appendix gives: some comments on general requirements for the method; a brief explanation of the equipment required; methods and procedures for performing the work. Source Amendment 1 to ITU-T Recommendation L.35 (1998) was agreed on 23 November 2007 by ITU-T
4、Study Group 6 (2005-2008). ii ITU-T Rec. L.35 (1998)/Amd.1 (11/2007) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sect
5、or (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 Standardization Assembly (WTSA), which meets every
6、 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 technology which fall within ITU-Ts purview,
7、 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. Compliance with this Recommendation is voluntar
8、y. 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 obligatory language such as “must“ and the neg
9、ative 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 implementation of this Recommendation may involve the
10、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 of the date of approval of this Recommendati
11、on, ITU had not 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 consult the TSB patent database at http:/
12、www.itu.int/ITU-T/ipr/. ITU 2008 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.35 (1998)/Amd.1 (11/2007) iii CONTENTS Page Appendix II Korean experience with access network installation procedure
13、s . 1 II.1 Introduction 1 II.2 Scope of Appendix II 1 II.3 Method for pulling out the copper cable from a duct and installing a new sub-duct for fibre-optic cable . 1 Bibliography. 4 ITU-T Rec. L.35 (1998)/Amd.1 (11/2007) 1 ITU-T Recommendation L.35 Installation of optical fibre cables in the access
14、 network Amendment 1 Insert new Appendix II with the following contents. Appendix II Korean experience with access network installation procedures II.1 Introduction With the advent of a highly networked society, the need for broadband services increases. To meet these service requirements, optical f
15、ibre networks are deployed extensively. The installation of optical fibre needs empty underground ducts and, if there are no spare ducts, additional ducts should be installed, which makes it expensive to deploy FTTx. Recently, copper cables are being replaced by fibre-optic cable to cope with the in
16、creasing number of FTTx subscribers. It is, however, difficult to pull out copper cable from the duct in which a big cable is placed by conventional winching equipment. It has been found that the pulling operation encounters difficulties when the diameter of copper cable is larger than 50 mm. The in
17、stallation of additional underground ducts is very important for deploying FTTx in urban areas where there are no spare ducts. Therefore, an easier method to pull out copper cables and to install sub-ducts for fibre-optic cables in the underground duct has been recently developed. General indication
18、s for the installation of any type of fibre are discussed in the main body of this Recommendation and Chapter II (Cable installation) of the Manual on Optical Fibre Cables “Construction, installation, jointing and protection of optical fibre cables“. This appendix provides more detailed information
19、about the installation of fibre-optic cables in the access network based upon the experiences of one country. II.2 Scope of Appendix II This appendix gives: some comments on general requirements for the method; a brief explanation of the equipment required; methods and procedures for performing the
20、work. II.3 Method for pulling out the copper cable from a duct and installing a new sub-duct for fibre-optic cable This method can be applied to pull out the unused or useless copper cables from an underground duct and to a install new sub-duct for fibre-optic cables in order to deploy FTTx. The mai
21、n purpose of this method is to secure new additional underground ducts on routes where there are no empty ducts. The advantage of this method is its speed of execution because pulling out copper cable and installing the sub-duct are done at the same time. It is not recommended that this method be ap
22、plied to ducts where multiple cables or sub-ducts are installed. This method is suitable for single-way duct unit systems including PVC and PE ducts that have inside diameters of 100 mm. It is recommended that the diameter of copper cable which will 2 ITU-T Rec. L.35 (1998)/Amd.1 (11/2007) be pulled
23、 out ranges from 50 to 87 mm, and the sub-duct which will be followed by copper cable has an outside diameter less than these ranges. It is estimated that the maximum pulling force is about 200 kN. II.3.1 Preparatory steps All precautions considered in other installation techniques shall be taken in
24、to account during the works. The pulling force is so great that precautions and preventive measures are provided. All rotating parts are covered for safety and a protective device is installed against excessive current and voltage. An emergency stop button is required in case of accident. All workme
25、n must remain outside the manhole and at least an agreed minimum distance from the machine during pulling out operations. In addition, the safety procedures described in b-ITU-T L.63 should be observed. The equipment and sub-duct drum are positioned as shown in Figure II.1. The subsidiary facilities
26、 such as hydraulic pump, controller and generator are also located near the equipment. It has to be taken into account that at least four persons are necessary to perform the installation process: one to set spare parts in the manhole; one to handle the cable drum and to connect the copper cable to
27、the sub-duct; one for any traffic control; and one to manage the overall operations. In case of long routes with many bends, it is recommended to apply an appropriate lubricant along the surface of a sub-duct. Figure II.1 Schematic layout II.3.2 Pulling out copper cable Due to the friction between t
28、he cable and duct, pulling out the copper cable from duct requires the application of great force. In addition, the force to grip the copper cable tightly is an important factor to be considered. The cable grip is designed so that the pulling force can be employed, and all works are operated by hydr
29、aulic pressure. The copper cable is pulled out using this equipment as shown in Figure II.2. The copper cables removed are then sent for recycling. ITU-T Rec. L.35 (1998)/Amd.1 (11/2007) 3 Figure II.2 Example of equipment for pulling out copper cables II.3.3 Inspection of host duct It is recommended
30、 that the host duct be inspected by test mandrel or by CCTV camera after the copper cable is pulled out completely. Test mandrel and CCTV systems can be used to ascertain the present state of the duct. If the host duct is deformed severely or has many defects, repairing work is carried out. II.3.4 I
31、nstallation of sub-duct The sub-duct follows the copper cable during the pulling operation. The sub-duct is connected tightly to the copper cable with a coupling device, and has enough tensile strength to withstand the pulling operation. HDPE duct is appropriate due to its flexibility and continuity
32、. The diameter of copper cable which will be pulled out ranges from 50 to 87 mm, and the outside diameter of the sub-duct used should be less than that of copper cable so that the sub-duct can enter the host duct without difficulties. To minimize the friction at the bends, it is preferable to use tu
33、rning wheels. 4 ITU-T Rec. L.35 (1998)/Amd.1 (11/2007) Bibliography b-ITU-T L.63 ITU-T Recommendation L.63 (2004), Safety procedures for outdoor installations. Printed in Switzerland Geneva, 2008 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series D General tariff princ
34、iples Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital ne
35、twork Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installation and protection of cables and other elements of outside plant Series M Telecommunication management, including TMN an
36、d network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Telephone transmission quality, telephone installations, local line networks Series Q Switching and signalling Series R Telegraph tra
37、nsmission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems
