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.977 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2015) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Optical fibre submarine cable systems Character
2、istics of optically amplified optical fibre submarine cable systems Recommendation ITU-T G.977 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 CARRIE
3、R-TRANSMISSION SYSTEMS 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
4、 RADIOTELEPHONY AND 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.
5、919 Digital sections 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 di
6、gital transmission 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.
7、1999 TRANSMISSION 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.977 (01/2015) i Recommendation ITU-T G.97
8、7 Characteristics of optically amplified optical fibre submarine cable systems Summary Recommendation ITU-T G.977 is concerned with the system performance and interface requirements of repeatered optical submarine systems using optical fibre amplifiers (OFAs) as line repeaters. It covers the aspects
9、 related to single wavelength systems (SWS), wavelength division multiplexing systems (WDMS) and dense wavelength division multiplexing systems (DWDMS). The physical implementation of optically amplified fibre submarine systems is considered in Annex A. This edition of the Recommendation introduces
10、a new power budget template for the implementation of coherent systems. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G.977 2000-04-04 15 11.1002/1000/5060 2.0 ITU-T G.977 2004-03-08 15 11.1002/1000/7070 3.0 ITU-T G.977 2006-12-14 15 11.1002/1000/8984 4.0 ITU-T G.977 2011-
11、04-13 15 11.1002/1000/11125 5.0 ITU-T G.977 2015-01-13 15 11.1002/1000/12369 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address 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
12、-T G.977 (01/2015) 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 Sector (ITU-T) is a permanent organ of ITU. ITU-T is r
13、esponsible 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 four years, establishes the topics for study by t
14、he 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, the necessary standards are prepared on a collabo
15、rative 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 voluntary. However, the Recommendation may contain certain
16、 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 negative equivalents are used to express requiremen
17、ts. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU
18、 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 Recommendation, ITU had received notice of intellectual prope
19、rty, 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:/www.itu.int/ITU-T/ipr/. ITU 2015 All rights reserved.
20、 No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.977 (01/2015) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 3 3.1 Terms defined elsewhere 3 3.2 Terms defined in this Recommendation . 4 4 Abbrev
21、iations and acronyms 8 5 Conventions 10 6 Characteristics and performances of the system . 10 6.1 Characteristics and performance of the digital line sections (DLSs) . 10 6.2 Optical power budget . 12 6.3 System reliability performance . 14 6.4 System capacity upgradeability 14 7 Characteristics and
22、 performance of the TTE 15 7.1 General . 15 7.2 Transmission performance . 16 7.3 Actions consequent to an alarm 16 7.4 Automatic switching . 16 8 Characteristics and performance of the optical submarine repeaters (OSRs) 16 8.1 Mechanical characteristics 16 8.2 Electrical characteristics . 17 8.3 Op
23、tical characteristics 17 8.4 Supervisory facilities 18 8.5 Fault location 18 8.6 Reliability . 19 9 Characteristics and performance of the in-line branching unit (BU) . 19 9.1 General . 19 9.2 Mechanical characteristics 20 9.3 Electrical characteristics . 21 9.4 Optical characteristics 21 9.5 Superv
24、isory facilities 21 9.6 Fault location 21 9.7 Reliability . 22 10 Characteristics and performance of the optical submarine equalizer (OSE) 22 10.1 Mechanical characteristics 22 10.2 Electrical characteristics (for adjustable OSEs only) . 23 10.3 Optical characteristics 23 10.4 Supervisory facilities
25、 23 iv Rec. ITU-T G.977 (01/2015) Page 10.5 Reliability . 23 11 Characteristics and performance of the submarine cable . 23 11.1 Dispersion mapping 23 11.2 Dispersion management implementation . 24 Annex A Implementation of repeatered optical fibre submarine cable systems using optical fibre amplifi
26、ers 25 A.1 Introduction 25 A.2 System configuration 25 A.3 System performance . 28 A.4 System operation 32 A.5 Optical submarine repeater (OSR), branching unit (BU) and optical submarine equalizer (OSE) characteristics . 33 Bibliography. 34 Rec. ITU-T G.977 (01/2015) 1 Recommendation ITU-T G.977 Cha
27、racteristics of optically amplified optical fibre submarine cable systems 1 Scope This Recommendation is concerned with the system performances and interface requirements of repeatered optical fibre submarine cable systems using optical line amplifiers (OFAs) as line repeaters. It covers the aspects
28、 related to single wavelength systems (SWS), wavelength division multiplexing systems (WDMS) and dense wavelength division multiplexing systems (DWDMS). Depending on the system specifications, such as the number of terminations, the connectivity, the total capacity, the maximum end-to-end distance,
29、and/or the system cost, one of these three types of systems may be more appropriate to guarantee the system requirements. A high data capacity may be carried by one wavelength using a high data bit-rate, or by several wavelengths using a smaller one. From a general point of view, the characteristics
30、, performance specifications and requirements of the submerged equipment are mostly identical for SWS, WDMS and DWDMS. Indeed, SWS appears as a specific case of WDMS using one wavelength and, in turn, WDMS can be considered as a specific case of DWDMS with a small number of wavelengths. As a consequ
31、ence, general statements mentioned in this Recommendation can be applied to SWS, WDMS and DWDMS. However, when necessary, more detailed Recommendations will highlight the specificity of these three types of systems. Common implementation aspects of optical submarine cable systems for manufacturing,
32、installing and maintenance are described in ITU-T G.971. ITU-T G.978 contains common aspects of the characteristics of the optical fibre submarine cables. ITU-T G.979 is also concerned with the characteristics of monitoring systems for optical fibre submarine cable systems with repeaters. The physic
33、al implementation of optically amplified fibre submarine systems is considered in Annex A. 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 edi
34、tions indicated were 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 val
35、id ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.661 Recommendation ITU-T G.661 (2007), Definitions and test methods for the relevant generic parameters of opti
36、cal amplifier devices and subsystems. ITU-T G.662 Recommendation ITU-T G.662 (2005), Generic characteristics of optical amplifier devices and subsystems. ITU-T G.664 Recommendation ITU-T G.664 (2012), Optical safety procedures and requirements for optical transmission systems. ITU-T G.692 Recommenda
37、tion ITU-T G.692 (1998), Optical interfaces for multichannel systems with optical amplifiers. 2 Rec. ITU-T G.977 (01/2015) ITU-T G.701 Recommendation ITU-T G.701 (1993), Vocabulary of digital transmission and multiplexing, and pulse code modulation (PCM) terms. ITU-T G.702 Recommendation ITU-T G.702
38、 (1988), Digital hierarchy bit rates. ITU-T G.703 Recommendation ITU-T G.703 (2001), Physical/electrical characteristics of hierarchical digital interfaces. ITU-T G.707 Recommendation ITU-T G.707/Y.1322 (2007), Network node interface for the synchronous digital hierarchy (SDH). ITU-T G.709 Recommend
39、ation ITU-T G.709/Y.1331 (2012), Interfaces for the optical transport network. ITU-T G.780 Recommendation ITU-T G.780/Y.1351 (2010), Terms and definitions for synchronous digital hierarchy (SDH) networks. ITU-T G.821 Recommendation ITU-T G.821 (2002), Error performance of an international digital co
40、nnection operating at a bit rate below the primary rate and forming part of an Integrated Services Digital Network. ITU-T G.823 Recommendation ITU-T G.823 (2000), The control of jitter and wander within digital networks which are based on the 2048 kbit/s hierarchy. ITU-T G.825 Recommendation ITU-T G
41、.825 (2000), The control of jitter and wander within digital networks which are based on the synchronous digital hierarchy (SDH). 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.
42、ITU-T G.828 Recommendation ITU-T G.828 (2000), Error performance parameters and objectives for international, constant bit-rate synchronous digital paths. ITU-T G.870 Recommendation ITU-T G.870/Y.1352 (2012), Terms and definitions for optical transport networks. ITU-T G.921 Recommendation ITU-T G.92
43、1 (1988), Digital sections based on the 2048 kbit/s hierarchy. ITU-T G.955 Recommendation ITU-T G.955 (1996), Digital line systems based on the 1544 kbit/s and the 2048 kbit/s hierarchy on optical fibre cables. ITU-T G.957 Recommendation ITU-T G.957 (2006), Optical interfaces for equipments and syst
44、ems relating to the synchronous digital hierarchy. ITU-T G.959.1 Recommendation ITU-T G.959.1 (2012), Optical transport network physical layer interfaces. ITU-T G.971 Recommendation ITU-T G.971 (2010), General features of optical fibre submarine cable systems. ITU-T G.972 Recommendation ITU-T G.972
45、(2011), Definition of terms relevant to optical fibre submarine cable systems. ITU-T G.975 Recommendation ITU-T G.975 (2000), Forward error correction for submarine systems. Rec. ITU-T G.977 (01/2015) 3 ITU-T G.975.1 Recommendation ITU-T G.975.1 (2004), Forward error correction for high bit-rate DWD
46、M submarine systems. ITU-T G.976 Recommendation ITU-T G.976 (2014), Tests methods applicable to optical fibre submarine cable systems. ITU-T G.978 Recommendation ITU-T G.978 (2010), Characteristics of optical fibre submarine cables. ITU-T G.979 Recommendation ITU-T G.979 (2012), Characteristics of m
47、onitoring systems for optical submarine cables. 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.8251 Recommendation ITU-T G.8251 (2010), The control of jitter and wander wit
48、hin the optical transport network (OTN). IEC 60825-1 IEC 60825-1 (2007), Safety of laser products Part 1: Equipment classification and requirements. IEC 60825-2 IEC 60825-2 (2007), Safety of laser products Part 2: Safety of optical fibre communication systems (OFCS). 3 Definitions 3.1 Terms defined
49、elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 compression factor: See ITU-T G.976. 3.1.2 digital line section (DLS): See ITU-T G.701. 3.1.3 forward error correction (FEC): See ITU-T G.972, ITU-T G.975 and ITU-T G.975.1. 3.1.4 gain flatness: See ITU-T G.976. 3.1.5 maximum channel power difference: See ITU-T G.692. 3.1.6 noise figure: See ITU-T G.661. 3.1.7 nominal gain: See ITU-T G.976. 3.
