1、 International Telecommunication Union ITU-T L.82TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (07/2010) SERIES L: CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT Optical cabling shared with multiple operators in buildings Recommendation ITU-T L.82 Rec. ITU-
2、T L.82 (07/2010) i Recommendation ITU-T L.82 Optical cabling shared with multiple operators in buildings Summary At this time, very high broadband network, especially FTTH (fibre to the home) deployment, is a major challenge for operators. One of the main issues is the terminal part of the network w
3、ith the introduction of optical fibre cables into building up to the apartment with technical difficulties but also administrative ones. Recommendation ITU-T L.82 deals with the solutions which could be deployed to try to answer to building owners, operators and customers needs. This Recommendation
4、refers to the single mode optical cabling in new and existing buildings. Clauses 5 and 6 explain the main constraints of a common optical infrastructure for several operators, offering FTTH services to customers in the same building. Then, the remainder of this Recommendation describes possible cabl
5、ing solutions which could be deployed in buildings. History Edition Recommendation Approval Study Group 1.0 ITU-T L.82 2010-07-29 15 ii Rec. ITU-T L.82 (07/2010) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, info
6、rmation 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 wo
7、rldwide 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
8、 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 conciseness to indicate both a telecommunication admi
9、nistration 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 pro
10、visions 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 RIGHTS ITU draws attention
11、 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, whether asserted by ITU members or others out
12、side 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 l
13、atest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2011 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 (07/2010) iii CONT
14、ENTS Page 1 Scope 1 2 References. 2 3 Terms and definitions . 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 2 4 Abbreviations 3 5 Shared building cabling 3 5.1 Single fibre architecture (one fibre for each customer, shared among different operators) . 3 5.2 Multi-fibres
15、architecture (more than one fibre for each customer, dedicated to single operators or shared among them) 3 6 Sharing point . 4 7 Vertical cabling and drop 5 7.1 Riser cable 5 7.2 Drop cable 5 7.3 Distribution point 6 8 Optical termination . 8 8.1 Customer outlet 8 8.2 Optical external network testin
16、g interface 9 9 Optical budget and return loss 9 10 Fibres 9 11 Connectors 9 Appendix I Answers to the questionnaire “Optical cabling shared with multiple operators in buildings“ 11 Bibliography. 13 iv Rec. ITU-T L.82 (07/2010) Introduction The proposed building cabling allows access to each operato
17、r to optical fibres in the building. The main goal of the concept is to be able to share the optical building cabling among different optical access providers. The objectives are, on one hand, to reduce fibre installation and maintenance costs in the building (both at the customer premises and in th
18、e common parts) and, on the other hand, to reduce disturbance (noise, infrastructure works, dust, etc.) for inhabitants. The goal is also to avoid the possibility for an operator to somewhat “pre-empt“ the optical link up to the customer in a building or to avoid cabling duplication if more than one
19、 FTTH operator is in a building. Rec. ITU-T L.82 (07/2010) 1 Recommendation ITU-T L.82 Optical cabling shared with multiple operators in buildings 1 Scope This Recommendation is effective when optical cabling in a building is shared with multiple optical access operators. Figure 1 shows a schematic
20、representation of what could exist in a building with multiple operators FTTH access networks, without shared cabling. L.82(10)_F01Operator 1Operator 3Operator 2Figure 1 Individual building cabling for each operator Many cables and boxes could be installed in common parts in this assumption, which c
21、an cause permanent disturbance for inhabitants. Besides, saturation of infrastructures could be reached with a strong impact on reliability of existing and new cables and on maintenance issues. A challenge for operators in that case could be to try to provide the condition for optical cabling sharin
22、g inside the building, as shown in Figure 2: L.82(10)_F02Operator 1sinternalwiringOperator 1sinternalwiringOperator 1Operator 3Operator 2Figure 2 Shared optical building cabling for all operators (when multiple “optical access networks“ are deployed) 2 Rec. ITU-T L.82 (07/2010) 2 References The foll
23、owing ITU-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 Reco
24、mmendation 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
25、 give it, as a stand-alone document, the status of a Recommendation. ITU-T G.652 Recommendation ITU-T G.652 (2009), Characteristics of a single-mode optical fibre and cable. ITU-T G.657 Recommendation ITU-T G.657 (2009), Characteristics of a bending loss-insensitive single-mode optical fibre and cab
26、le for the access network. ITU-T L.12 Recommendation ITU-T L.12 (2008), Optical fibre splices. ITU-T L.36 Recommendation ITU-T L.36 (2008), Single-mode fibre optic connectors. ITU-T L.59 Recommendation ITU-T L.59 (2008), Optical fibre cables for indoor applications. ITU-T L.87 Recommendation ITU-T L
27、.87 (2010), Optical fibre cables for drop applications. 3 Terms and definitions 3.1 Terms defined elsewhere This Recommendation uses the following term defined elsewhere: 3.1.1 single element b-IEC 61756-1 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.
28、1 building optical line: Optical line between the sharing point at the building basement and the customer outlet. 3.2.2 building operator: Operator who installs and is responsible for the maintenance of the vertical and/or horizontal cabling in the building and gives an access to it to the other ope
29、rators. 3.2.3 customer outlet: Allows the connection of fibre(s) from a cable to the ONT. 3.2.4 distribution point: When it exists, the distribution point is the point where customers are connected to the vertical part of the building cabling with an individual cable (the drop cable) by splice and/o
30、r connector. The customer could be also connected extracting fibres from the riser cable and routing them to the customer premises. 3.2.5 dedicated fibre: Fibre dedicated for only one operator, which is available permanently for this operator. 3.2.6 drop cable: Individual cable which links up the di
31、stribution point or the sharing point to the customer outlet or the optical external network testing interface. This cable can be composed of one or more fibres. 3.2.7 optical external network testing interface: Physical point at which a subscriber is provided with access to an optical communication
32、s network. 3.2.8 shared fibre: Fibre shared between several operators, which is available temporarily for one operator. Rec. ITU-T L.82 (07/2010) 3 3.2.9 sharing point: Interface between optical access networks of different operators and the optical building cabling. 3.2.10 vertical cabling: Part of
33、 the building cabling between the sharing point and the distribution point when it exists. 4 Abbreviations This Recommendation uses the following abbreviations and acronyms: CO Customer Outlet ENTI External Network Testing Interface FTTH Fibre To The Home ONT Optical Network Termination 5 Shared bui
34、lding cabling The building operator or the building owner may take the initiative in cabling a building. They should expect to give access to operators to the optical building lines with a sharing point at the building basement. The number of operators should be limited by a maximum, for practical d
35、eployment reasons and based on the real needs of the market. The “building operator“ deploying the building optical cabling could be in charge of the installation and/or maintenance of this sharing point. The shared building cabling combined with the sharing point should support both point-to-point
36、and point-to-multipoint access network topologies. So, a point-to-point network should be used by all the operators between the building basement and customer outlets or the external network testing interfaces. 5.1 Single fibre architecture (one fibre for each customer, shared among different operat
37、ors) Choice could be made to deploy only one fibre per customer in the vertical part of the building and to share it between the different operators. This choice could be made by the building operator or by the owner of the building, depending on free room in the vertical shaft. Operators could have
38、 access to shared fibres at the sharing point. Fibres are temporarily assigned to one operator, when needed, to give access to services for customers. The single fibre dedicated to the customer could be contained in a single drop cable or in a multi-fibres riser cable (see clause 7). 5.2 Multi-fibre
39、s architecture (more than one fibre for each customer, dedicated to single operators or shared among them) Choice could be also made to deploy a multi-fibres architecture based on the installation of minimum 2 fibres per apartment, in which a fibre is dedicated to each operator. Operators could have
40、 access to dedicated fibres at the sharing point, which are permanently available for their own use. It could be also possible to give access to shared fibres with this architecture. 4 Rec. ITU-T L.82 (07/2010) 6 Sharing point The sharing point is the interface between optical access networks of dif
41、ferent operators and the optical building cabling. It should be compatible with point-to-point or point-to-multipoint optical access network architectures. Depending on building area and network topologies, the sharing point could be used for one building when the building size is sufficient, but co
42、uld also be shared between several buildings. It could be installed inside or outside buildings. Information about the localization, number of apartments connected, owner and type of sharing point should be available for all operators. It represents: a flexibility point where we can manage the alloc
43、ation of customers fibres between operators; a demarcation point to separate the responsibility of each operator; a point for optical measurements (mainly attenuation and return loss). The sharing point should be composed of three parts (Figure 3): a “customers area“ for the management of fibres fro
44、m riser cables or drop cables (customer module); “operators areas“ dedicated for each operator for the management of fibres coming from their access network. These separated areas could be sort of modules with connectors or splice trays, for example. They should be able to accept potential splitters
45、. When it is not possible, splitters could be installed in another box; a “connection area“ for the interconnection between fibres of the building cabling and access networks with use of patchcords or pigtails. L.82(10)_F03Operators access cablesConnection areaOperators areasCustomers areaRiser or d
46、rop cablesFigure 3 Illustration of a sharing point In case of a single fibre sharing architecture, the sharing point should allow an “any to any“ cross-connection between shared fibres of the building cabling and fibres from the access networks of each operator. When a multi-fibres architecture is d
47、eployed in the building, the sharing point should allow, for each operator which has a dedicated fibre in the building, the connection of its own building cabling fibres with fibres from its access network. The sharing point could give both access to dedicated fibres and shared fibres in case of som
48、e operators wanting to share their fibres. Rec. ITU-T L.82 (07/2010) 5 The sharing point should be designed to allow: frequent arrangements of fibres; new cable installation or older cable replacement; add-on or replacement of optical splitters when splitters are considered inside the sharing point
49、(for PON access networks); splicing operations (fusion or mechanical). The customers area should be dimensioned for all customers at day one. It could be useful to have the possibility to install operators areas only when needed with a modular solution. The sharing point should respect environmental standards (climatic, mechanical, dust, etc.) to allow indoor and outdoor settings. 7 Vertical cabling and drop Based on operators consensus, different cabling systems could be installed in the vertical and drop parts: easy mi
