1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T L.82 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1 (12/2014) SERIES L: ENVIRONMENT AND ICTS, CLIMATE CHANGE, E-WASTE, ENERGY EFFICIENCY; CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS O
2、F OUTSIDE PLANT Optical cabling shared with multiple operators in buildings Amendment 1: New Appendix II Recommendation ITU-T L.82 (2010) Amendment 1 Rec. ITU-T L.82 (2010)/Amd.1 (12/2014) i Recommendation ITU-T L.82 Optical cabling shared with multiple operators in buildings Amendment 1 New Appendi
3、x II A new multifibre riser cable structure for FTTH MDU cabling: the Italian experience Summary Amendment 1 to Recommendation ITU-T L.82 (2010) adds a new appendix that describes a new cable structure designed and used in Italy to facilitate cable installation in vertical building risers of existin
4、g buildings in FTTH deployments. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T L.82 2010-07-29 15 11.1002/1000/10915 1.1 ITU-T L.82 (2010) Amd. 1 2014-12-05 15 11.1002/1000/12413 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of y
5、our web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T L.82 (2010)/Amd.1 (12/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, informa
6、tion 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 view to standardizing telecommunications on a world
7、wide 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 Recommendations is covered by the procedure laid down in WT
8、SA 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 conciseness to indicate both a telecommunication adminis
9、tration 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 is achieved when all of these mandatory provis
10、ions 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. INTELLECTUAL PROPERTY RIGHTSITU draws attention to
11、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, whether asserted by ITU members or others outside
12、 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 cautioned that this may not represent the lates
13、t information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 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 L.82 (2010)/Amd.1 (12/2014)
14、 iii Table of Contents Page Appendix II A new multifibre riser cable structure for FTTH MDU cabling: the Italian experience . 1 II.1 Introduction 1 II.2 Background . 1 II.3 Multifibre cable 3 II.4 Cable perfomance . 5 II.5 Installation procedure . 5 II.6 Conclusions 7 Rec. ITU-T L.82 (2010)/Amd.1 (1
15、2/2014) 1 Recommendation ITU-T L.82 Optical cabling shared with multiple operators in buildings Amendment 1 New Appendix II 1) Introduce a new appendix, Appendix II after Appendix I. Appendix II A new multifibre riser cable structure for FTTH MDU cabling: the Italian experience (This appendix does n
16、ot form an integral part of this Recommendation.) II.1 Introduction This appendix describes a new cable structure designed and used in Italy to facilitate cable installation in vertical building risers of existing buildings in FTTH deployments. II.2 Background The “Brownfield“ scenario (existing bui
17、ldings) represents the most difficult case for optical fibre installation in Italy, due to the limited availability of telecommunication infrastructure (i.e., ducts from the basement to the dwelling units) and difficulties in obtaining householder authorization for new installations, especially for
18、visible-cable solutions. One of the most important constraints is the lack of space in the existing vertical infrastructures of multi-dwelling units (MDUs) that could already be crowded by other cables, such as metallic telecommunication cables, TV antennae or CATV coaxial cables and electrical cabl
19、es. Small diameter ducts could also be an issue. Some examples are shown in the figures below. 2 Rec. ITU-T L.82 (2010)/Amd.1 (12/2014) Figure II.1 Examples of existing infrastructures A suitable riser cable in such an environment shall optimize the following aspects: fibre count/diameter ratio bend
20、ing characteristics flexibility low friction between the inside fibres and the external sheath lightweight single fibre management and reliability. It has to be noted that these kinds of properties are also useful for installation inside central offices and data centres, wherever the cable routing b
21、etween different ODFs, located in different rooms, poses similar technical challenges; moreover, in this case, it is also important to consider the ease of management and reconfiguration, the coiling of extra lengths, etc. This is given here only as general information because central offices and da
22、ta centres are outside the terms of reference of this Recommendation. Rec. ITU-T L.82 (2010)/Amd.1 (12/2014) 3 Taking into account the above items, a multifibre cable composed of reinforced single tight fibre cords, stranded together in a loose structure has been developed and used in Italy. II.3 Mu
23、ltifibre cable II.3.1 Structure This cable is made up of a number of single fibre cords, assembled in a longitudinal loose structure (without helicoidal stranding), within an external low smoke zero halogen (LSZH) sheath. The design of the sheath of this cable minimizes friction during installation
24、in crowded existing ducts, as well as allowing individual fibres to be managed more easily; in particular, the fibres can slip down their respective pathways with ease. The diameter of a 24-fibre cable should be 8.5 0.5 mm. Also 12 and 8 fibre solutions are available. The cable can be pre-connectori
25、zed in the factory. II.3.2 Single fibre unit characteristics The optical fibre used could comply with ITU-T G.657.A1 or ITU-T G.657.A2 fibres. The fibre is surrounded by: a 350 50 m diameter soft coating, easily stripped for splicing operations, that could be added to reinforce the fibre (especially
26、 suitable in the pre-connectorized configuration); an aramidic yarn strength member, to withstand the pulling forces during the drawing of the cable and while extracting fibres; a thermoplastic compound outer sheath of 850 900 m diameter. The friction coefficient of the sheath is low enough to allow
27、 the fibre to slip to enable the extraction operation between floors. The resulting single fibre cords are colour coded. II.3.3 Cable fibre count and dimensions The maximum 24-fibre cable diameter is 8.5 mm, with an external LSZH sheath which is 1.25 mm thick. A structure with 36 fibres is also poss
28、ible, extending the overall outer diameter to 9.5 mm. 4 Rec. ITU-T L.82 (2010)/Amd.1 (12/2014) Figure II.2 Single tight fibre cord and multifibre cable scheme II.3.4 Connectorization The cable can be connectorized with a variety of connectors, complying with ITU-T L.36 and the relevant IEC standards
29、, according to customer requirements. Figure II.3 Examples of pre-terminated cables Rec. ITU-T L.82 (2010)/Amd.1 (12/2014) 5 II.4 Cable perfomance The cable performance has been checked in accordance with IEC standards: b-IEC 60189-1 for dimensions (maximum diameter and External sheath thickness); b
30、-IEC 60794-1-2 for mechanical tests (method E1 tensile test and attenuation changes, E3 crush, E11 bending, E4 percussion test, E5 stripping force stability of fibres, E10 kink) and environmental tests (F21 thermal cycles); b-IEC TR 62222 for fire behaviour (propagation, smoke density); The connecto
31、rized solution has been checked in accordance with a set of test methods from b-EN 61300-2 and b-EN 61300-3. II.5 Installation procedure Complete solutions developed for FTTH MDU building cabling consist of a basement box, housing pre-connectorized splitters and cable terminations, the multifibre ri
32、ser cable (with a number of fibres according to the total number of customers), and protection for the extracted fibres and for the splices at floors. Fibres are spliced to a horizontal drop cable to reach the customer wall outlet. The steps necessary to extract fibres from the multifibre cable (Fig
33、ure II.4) can be delicate and have to be followed accurately, in order not to damage the fibres: a window is opened (Figure II.6) in the sheath of the riser cable, using a calibrated tool (to avoid cutting fibres), at each floor (step n.1); a protection shell or small box (Figure II.7) is installed
34、over the opened part of the cable and fixed to the cable, by means of a clamping system, starting from the lowest floor (step n.2); the fibres to be extracted at floor “n“ (one fibre for each apartment) are identified in the cable at the upper “(n+x)“ floor, by means of a colour code, and shall be c
35、ut (step n.3). The x value depends on the length of the fibre required at floor “n“, in order to reach the appropriate point to host the fusion splice for the future customer connection; at floor “n“, the fibres are pulled, extracting them for a length corresponding to the distance between the two f
36、loors (step n.4). After their extraction the fibres are cut, leaving only the required length necessary to make a fusion splice (about 1 m); each extracted fibre is inserted into a protection tube, fixed inside a shell, or in a suitable small box that could contain the splice (Figure II.7). 6 Rec. I
37、TU-T L.82 (2010)/Amd.1 (12/2014) Figure II.4 Example of fibres extraction procedure from the multifibre cable In the following pictures some examples of the protection system at floor, for vertical cable and splice, are shown. Figure II.5 Riser cable installed in existing infrastructure Rec. ITU-T L
38、.82 (2010)/Amd.1 (12/2014) 7 Figure II.6 A window is open on the cable sheath Figure II.7 Installation of the fibre protection shell (left different dimensions are available) with protection tubes or splice box (right) II.6 Conclusions After extensive trials, this riser cable solution has proved to
39、be effective to tackle the challenges posed by FTTH installation in existing buildings, typical in the “European environment“, where it is mandatory to use miniaturized solutions to reach the customer without copper removal. 8 Rec. ITU-T L.82 (2010)/Amd.1 (12/2014) Moreover, this cable construction
40、has also proved promising for central office and data centre applications, reducing the volume of the cabling itself and at the same time allowing a more ordered routing inside the central office mechanical structures. This is given for general information because central offices and data centres is
41、 out of the terms of reference of this Recommendation. 2) Add the following references to the bibliography. b-IEC 60189-1 IEC 60189-1 (2007), Low-frequency cables and wires with PVC insulation and PVC sheath Part 1: General test and measuring methods. b-IEC 60794-1-2 IEC 60794-1-2 (2013), Optical fi
42、bre cables Part 1-2: Generic specification Cross reference table for optical cable test procedures. b-IEC TR 62222 IEC TR 62222 (2012), Fire performance of communication cables installed in buildings. b-EN 61300-2.xx IEC EN 61300-2.xx series of standards (in force), Fibre optic interconnecting devic
43、es and passive components. Basic test and measurement procedures. Tests.xx NOTE This refers to a series of EN norms, i.e., 61300-2-xx. b-EN 61300-3.xx IEC EN 61300-3.xx series of standards (in force), Fibre optic interconnecting devices and passive components. Basic test and measurement procedures.
44、Examination and measurements.xx NOTE This refers to a series of EN norms, i.e., 61300-3-xx. Printed in Switzerland Geneva, 2015 SERIES OF ITU-T RECOMMENDATIONS Series A Organization of the work of ITU-T Series D General tariff principles Series E Overall network operation, telephone service, service
45、 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 network Series J Cable networks and transmission of television, sound
46、programme and other multimedia signals Series K Protection against interference Series L Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant Series M Telecommunication management, including TMN and
47、network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Terminals and subjective and objective assessment methods Series Q Switching and signalling Series R Telegraph transmission Series S Te
48、legraph 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
