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 G.971 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2016) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL- SYSTEMS AND NETWORKS Digital sections and digital line system Optical fibre submarine cable systems General
2、features of optical fibre submarine cable systems Recommendation ITU-T G.971 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYS
3、TEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AN
4、D LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 General G.900G.909 Parameters for optical fibre cable systems G.910G.919 Digital sectio
5、ns at hierarchical bit rates based on a bit rate of 2048 kbit/s G.920G.929 Digital line transmission systems on cable at non-hierarchical bit rates G.930G.939 Digital line systems provided by FDM transmission bearers G.940G.949 Digital line systems G.950G.959 Digital section and digital transmission
6、 systems for customer access to ISDN G.960G.969 Optical fibre submarine cable systems G.970G.979 Optical line systems for local and access networks G.980G.989 Metallic access networks G.990G.999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION
7、MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.971 (11/2016) i Recommendation ITU-T G.971 General features
8、 of optical fibre submarine cable systems Summary Recommendation ITU-T G.971 applies to optical fibre submarine cable systems. The purpose of this Recommendation is to identify the main features of optical fibre submarine cable systems, and to provide generic information on relevant Recommendations
9、in the field of optical fibre submarine cable systems. A common implementation relevant to all the optical fibre submarine cable systems is described in Annex A. Specific information relevant to each optical fibre submarine cable systems is included in annexes of other Recommendations. The updated d
10、ata on cable ships and submersible equipment of various countries are also described in Appendix I. In this latest version, relationship among Recommendations relevant to optical fibre submarine cable systems found in section 7 is amended to take into account three groups of “General“, “Components o
11、r Functions“ and “System Requirements“. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G.971 1993-03-12 XV 11.1002/1000/1036 2.0 ITU-T G.971 1996-11-11 15 11.1002/1000/3830 3.0 ITU-T G.971 2000-04-04 15 11.1002/1000/5059 4.0 ITU-T G.971 2004-06-13 15 11.1002/1000/7339 5.0 I
12、TU-T G.971 2007-07-29 15 11.1002/1000/9157 6.0 ITU-T G.971 2010-07-29 15 11.1002/1000/10882 7.0 ITU-T G.971 2016-11-13 15 11.1002/1000/13088 Keywords Cable ship, optical fibre submarine cable systems, submersible equipment. * To access the Recommendation, type the URL http:/handle.itu.int/ in the ad
13、dress field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T G.971 (11/2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, inf
14、ormation 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 w
15、orldwide 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 i
16、n 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 adm
17、inistration 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 pr
18、ovisions 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
19、 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
20、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
21、atest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2017 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 G.971 (11/2016) iii Tab
22、le of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 3.1 Terms defined elsewhere 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 Features of optical fibre submarine cable systems . 2 7 Relationship among Recommendations relevant to optical fibre submarine cable systems 4 Annex A Commo
23、n implementation aspects of optical submarine cable systems for manufacturing, installing and maintenance 6 A.1 Introduction 6 A.2 Manufacturing 6 A.3 System installation 7 A.4 System commissioning . 8 A.5 Maintenance . 8 Appendix I Data on cable ships and submersible equipments of various countries
24、 . 10 I.1 Cable ships 10 I.2 Submersible equipments . 17 Bibliography. 23 Rec. ITU-T G.971 (11/2016) 1 Recommendation ITU-T G.971 General features of optical fibre submarine cable systems 1 Scope This Recommendation applies to optical fibre submarine cable systems. The purpose of this Recommendation
25、 is to identify the main features of optical fibre submarine cable systems, and to provide generic information on relevant Recommendations in the field of optical fibre submarine cable systems. Annex A contains common implementation aspects of all optical submarine cable systems. Appendix I contains
26、 data on cable ships and submersible equipments of various countries. 2 References The following 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
27、valid. All Recommendations and other references are subject to revision; users of this Recommendation 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 Recommendati
28、ons is regularly published. The reference to a document within this Recommendation does not give it, as a standalone document, the status of a Recommendation. ITU-T G.821 Recommendation ITU-T G.821 (2002), Error performance of an international digital connection operating at a bit rate below the pri
29、mary rate and forming part of an Integrated Services Digital Network. ITU-T G.826 Recommendation ITU-T G.826 (2002), End-to-end error performance parameters and objectives for international, constant bit-rate digital paths and connections. ITU-T G.828 Recommendation ITU-T G.828 (2000), Error perform
30、ance parameters and objectives for international, constant bit-rate synchronous digital paths. ITU-T G.8201 Recommendation ITU-T G.8201 (2011), Error performance parameters and objectives for multi-operator international paths within optical transport networks. ITU-T G.972 Recommendation ITU-T G.972
31、 (2016), Definition of terms relevant to optical fibre submarine cable systems. ITU-T G.973 Recommendation ITU-T G.973 (2016), Characteristics of repeaterless optical fibre submarine cable systems. ITU-T G.973.1 Recommendation ITU-T G.973.1 (2009), Longitudinally compatible DWDM applications for rep
32、eaterless optical fibre submarine cable systems. ITU-T G.973.2 Recommendation ITU-T G.973.2 (2011), Multichannel DWDM applications with single channel optical interfaces for repeaterless optical fibre submarine cable systems. 2 Rec. ITU-T G.971 (11/2016) ITU-T G.974 Recommendation ITU-T G.974 (2007)
33、, Characteristics of regenerative optical fibre submarine cable systems. ITU-T G.977 Recommendation ITU-T G.977 (2015), Characteristics of optically amplified optical fibre submarine cable systems. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the terms defined in ITU-T G.972. 4
34、 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: BAS Burial Assessment Survey BOL Beginning of Life BU Branching Unit CPT Cone Penetrometer Testing CTE Cable Terminating Equipment DP-system Dynamic Positioning-system DWDM Dense Wavelength Division Multip
35、lexing PFE Power Feeding Equipment PLGR Pre-Lay Grapnel Run ROV Remotely Operated Vehicle SCARAB Submersible Craft Assisting Repair and Burial SWL Safe Working Load TSE Terminal Station Equipment TTE Terminal Transmission Equipment 5 Conventions None. 6 Features of optical fibre submarine cable syst
36、ems An optical fibre submarine cable system has specific technical features: a) A submarine cable system should have a long lifetime and be highly reliable. The main reason for this that the construction and maintenance of a link is long and expensive because of the difficulty in accessing a submerg
37、ed plant. Moreover, most submarine links are of strategic importance in the transmission network the interruption of a link usually results in significant loss of traffic and revenue. Rec. ITU-T G.971 (11/2016) 3 b) A submarine cable system should possess mechanical characteristics which enable it:
38、1) to be installed accurately with correct slack and with due attention to safety considerations on the seabed deep water installations can reach up to 8,000 metres. (In general, submarine cable systems shall be installed, buried or inspected by specially designed cable ships and submerged equipment
39、. Detailed information of such cable ships and submerged equipment (i.e., ploughs, ROVs, etc.) is contained in Appendix I); 2) to resist environmental conditions on the sea bottom at the installation depth, particularly hydrostatic pressure, temperatures, abrasion, corrosion and marine life; 3) to b
40、e adequately protected (i.e., by armouring or burying) against aggression, due for example to trawlers or anchors; 4) to survive recovery from such a depth, and subsequent repair and relay, with due safety considerations. c) The material characteristics of a submarine cable system should enable the
41、optical fibre: 1) to achieve its desired reliability over its design lifetime; 2) to tolerate stated loss and aging mechanisms, especially bending, strain, hydrogen, stress, corrosion and radiation. d) The transmission quality of a submarine cable system should follow, as a minimum ITU-T G.821 or IT
42、U-T G.826 or ITU-T G.828 or ITU-T G.8201. Figure 1 shows the basic concept of optical fibre submarine cable systems and boundaries. Optical submarine repeaters or optical submarine branching units could be included, depending on each system requirement. In Figure 1, “A“ denotes the system interfaces
43、 at the terminal station (where the system can be interfaced to terrestrial digital links or to other submarine cable systems), and “B“ denotes beach joints or landing points. Numbers in brackets in the figure refer to ITU-T G.972. 4 Rec. ITU-T G.971 (11/2016) G .9 7 1 ( 1 0 ) _ F 0 1L an d por t i
44、on ( 1 004 ) Sub m a r i ne po r t i on ( 100 5) L an d por t i on ( 1 004 )TTE( 101 0)C T E( 101 4)O pt i c als u bm ar i ner ep ea t e r( 102 0) R ep ea t erBU( 102 2) R ep ea t er R ep ea t erASB BRAC T E TTESup er v i s or ys e ct i o n( 200 7)E l em en t ar yca bl e s ec t i on( 102 8)ABC T E T
45、TEPFE M ai nt e na n ceco nt r ol l e rPFE M ai nt e na n ceco nt r ol l e rM ai nt e na n ceco nt r ol l e r( 101 2)C ab l ej oi n t i ngbox ( 501 3)N O T E 1 de not es s y s t em i nt er f a ce .N O T E 2 de not es l an di ng po i nt s or b ea c h j oi nt s ( 1 006 ) .N O T E 3 de not es ca bl e j
46、 oi nt i n g b ox ( 50 13) .N O T E 4 N um b er i n b r a ck e t s r el at e t o I T U - T G . 9 72 .A B XO IR ep ea t erR ep ea t erPFE( 101 3)O pt i c al f i b r e s u bm ar i ne c ab l e ( 1 019 )O pt i c al f i b r e l an d ca bl e ( 10 18)O pt i c al f i b r e s t at i on ca b l e ( 101 7 )E l
47、ec t r i ca l ca bl eO pt i c al i nt er f ac e ( 20 09)Sys t e m i nt er f ac e ( 20 08)Figure 1 Example of optical fibre submarine cable systems 7 Relationship among Recommendations relevant to optical fibre submarine cable systems Relationships among the various Recommendations pertaining to opti
48、cal fibre submarine cable systems are shown in the flow chart presented in Figure 2. Recommendations relevant to optical fibre submarine cable systems can be categorized into three groups. The first group covers general aspects on optical fibre submarine cable systems. This category is composed of I
49、TU-T G.971, ITU-T G.972 and b-ITU-T G.Sup.41. These documents respectively describe general features, definitions and design guidelines for optical fibre submarine systems. The second group deals with the components or functions used in optical fibre submarine systems. This category is composed of b-ITU-T G.975, b-ITU-T G.975.1, b-ITU-T G.976, b-ITU-T G.978 and b-ITU-T G.979. These documents describe forward error correction, advanced forward error correction, test methods, opti
