1、INTERNATIONAL TELECOMMUNICATION UN ION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU L.35 (1 0/98) SERIES L: CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT Installation of optical fibre cables in the access network ITU-T Recommendation L.35 (Previousl
2、y CCITT Recommendation) STD-ITU-T RECMN L-35-ENGL 1998 m 4862591 Ub53bb5 Ob1 m ITU-T L-SERIES RECOMMENDATIONS CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT For further details, please refer to ITU-T List of Recommendations. STD-ITU-T RECMN L-35-ENGL 2998 D 4
3、Bb32593 Ob53bbb TTB = ITU-T RECOMMENDATION L.35 INSTALLATION OF OPTICAL FIBRE CABLES IN THE ACCESS NETWORK Summary The Recommendation gives information about the methodologies recommended to install fibre optic cables in the access network. In particular, it gives guidance for installation in ducts,
4、 aerial installation and directly buried cables. Appendix I provides the experiences of nine countries on this matter. Source ITU-T Recommendation L.35 was prepared by ITU-T Study Group 6 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 9th of October 1998. FOREWORD IT (
5、International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Re
6、commendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these t
7、opics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Re
8、commendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve
9、the use of a claimed Intellectual Property Right. The 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 Reco
10、mmendation, the ITU 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 information and are therefore strongly urged to consult the TSB patent databa
11、se. O ITU 1998 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 Recommendation L.35 (10/98) STD.ITU-T RECMN L-35-ENGL 1778 113 48b
12、2571 Ob53bb8 870 I CONTENTS Page Appendix I - International experience on access network installation procedures . I. 1 General aspects . 2 1.2 Duct installation. . 2 1.3 Directly buried cables . 3 1.4 Aerial installation . 3 2 Recommendation L.35 (10/98) . 111 STD.ITU-T RECMN L.35-ENGL 1778 II 48b2
13、571 Ob53bb 707 Recommendation L.35 INSTALLATION OF OPTICAL FIBRE CABLES IN THE ACCESS NETWORK (Geneva, 1998) Introduction Optical fibres have been used for some time as transmission media in the access network. The different network architectures used are described in Annex AL. 1 5. The procedure fo
14、r connecting customers to the public switched telephone network via optical fibre is described in Recommendation L. 17. In addition, Chapter II (Cable installation) of the Manual on Optical Fibre Cables “Construction, installation, jointing and protection of optical fibre cables“ provides general in
15、dications for the installation of any type of fibre; more detailed indications may, however, be necessary for the installation of optical fibre cables in the access network. Considering - - that the optical fibre access network is expanding rapidly; that the characteristics of the network are, in ma
16、ny cases, different from those of other types of network; that this type of network can be installed in different environments: rural, suburban and urban; that although installation in ducts is common, directly buried or aerial installations are also possible; that there are certain options in each
17、type of installation that may prove advantageous, - - - it is recommended 1) In general: - that a study of economic factors, environmental impact and rules or regulations in each region should be conducted to decide on the type of installation: in ducts, directly buried or aerial; that existing infr
18、astructure should be used wherever possible (ducts, poles, etc.); that installation should be undertaken by qualified staff who are skilled in the type of installation chosen. If the installation is in ducts: that manholes or boxes should be used as network splice and flexibility points; that when t
19、he diameter of the duct permits and PE or PVC sub-ducts are used, then they should be installed within the duct typically by pulling; that cables should be installed in the duct by any of the methods described in Chapter II (Cable installation) of the Manual on Optical Fibre Cables; that when requir
20、ed, the cable should be installed from an intermediate point, laying part of the cable as a figure eight; that consideration be given to the storage of excess cable in boxes or manholes. - - 2) - - - - - Recommendation L.35 (10/98) 1 - - 3) - - If the cable is directly buried: that the splice cases
21、should be directly buried or protected by a prefabricated box; that any of the traditional methods described in Chapter II (Cable installation) of the Manual on Optical Fibre Cables should be used. If the installation is aerial: that poles should be made of wood, cement, steel, fibre or plastic depe
22、nding on the results of the economic and environmental impact study; that either the cable should be lashed to or twisted around a support cable/wire or a self-supporting cable should be used; that the cable should be suspended on all poles, however at special positions, for example: splice poles; e
23、nd of the route; river or road crossing; the cable should be anchored (fixed to the pole), in order to transfer the main load from the cable on to the pole; a length of cable for cable splicing purposes should be stored at splicing positions. 4) - - - every given number of poles, - APPENDIX I Intern
24、ational experience on access network installation procedures The information in this appendix has been summarized from the replies from nine countries to a questionnaire sent to ITU-T Study Group 6 participants. The range of data shown incorporates the minimum and maximum values provided within the
25、replies. 1.1 1.1.1 1.1.2 1.1.3 1.2 1.2.1 1.2.2 1.2.3 1.2.4 1.2.5 1.2.6 1.2.7 2 General aspects Mean distance from exchange to customer: 300-5000 m Maximum distance from exchange to customer: 2-30 km Type of installation: Mainly in ducts Duct installation Number of manholes and boxes per km along the
26、 route: 1-30 Duct material: PVC, HDPE, PE, earthenware and steel Internal diameter of the duct bore: 27-125 mm Sub-duct material: PVC and PE Internal diameter of sub-ducts: 14-44 mm Maximum cable length between splices: 400-6000 m Excess length of cable stored in boxes (when applicable): 2-22 m Reco
27、mmendation L.35 (10/98) _ - STD-ITU-T RECMN L.35-ENGL 1998 48b259L 0653b7L 365 W 1.3 Directly buried cables 1.3.1 Maximum length between splices: 2000-6000 m 1.4 Aerial installation 1.4.1 1.4.2 1.4.3 1.4.4 Mean length between poles: 25-80 m Maximum length between poles: 50-200 m Profile of self-supp
28、orting cable (when applicable): Figure 8 and circular shape Excess cable length in splicing points: 0.8-10 m Recommendation L.35 (10198) 3 _ . . STD-ITU-T RECMN L-35-ENGL 1798 48b257L Ob53b73 D Series A Series B Series C Series D Series E Series F Series G Series H Series I Series J Series K Series
29、L Series M Series N Series O Series P Series Q Series R Series S Series T Series U Series V Series X Series Y Series Z ITU-T RECOMMENDATIONS SERIES Organization of the work of the ITU-T Means of expression: definitions, symbols, classification General telecommunication statistics General tariff prin
30、ciples Overall network operation, telephone service, service operation and human factors Non-telephone telecommunication services Transmission systems and media, digital systems and networks Audiovisual and multimedia systems Integrated services digital network Transmission of television, sound prog
31、ramme and other multimedia signals Protection against interference Construction, installation and protection of cables and other elements of outside plant TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Maintenance: inter
32、national sound programme and television transmission circuits Specifications of measuring equipment Telephone transmission quality, telephone installations, local line networks Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminals for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communications Global information infiastructure Programming languages Printed in Switzerland Geneva, 1998
