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 Series G TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Supplement 39 (02/2016) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Optical system design and engineering considerations ITU-T G-series Rec
2、ommendations Supplement 39 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 SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTE
3、RNATIONAL 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 AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND
4、 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 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.69
5、99 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. G series Supplement 39 (02/2016) i Supplement 39 to ITU-T G-series Recommendations Optical system design
6、 and engineering considerations Summary Supplement 39 to ITU-T G-series Recommendations provides information on the background and methodologies used in the development of optical interface Recommendations such as ITU-T G.691, ITU-T G.957 and ITU-T G.959.1. This edition adds further information on m
7、odulation formats; clarifies power budget parameters for systems with optical amplifiers; provides further information on the optical signal-to-noise ratio (OSNR) measurement; updates information on concatenation of non-linear effects; adds bit error ratio (BER) estimation technique based on constel
8、lation and makes other miscellaneous corrections. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G Suppl. 39 2003-10-31 15 11.1002/1000/7049 2.0 ITU-T G Suppl. 39 2006-02-17 15 11.1002/1000/8749 3.0 ITU-T G Suppl. 39 2008-12-12 15 11.1002/1000/9684 4.0 ITU-T G Suppl. 39 201
9、2-09-21 15 11.1002/1000/11765 5.0 ITU-T G Suppl. 39 2016-02-26 15 11.1002/1000/12840 * 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 G s
10、eries Supplement 39 (02/2016) 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.
11、 ITU-T is responsible 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
12、 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 WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared o
13、n a collaborative basis with ISO and IEC. NOTE In this publication, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this publication is voluntary. However, the publication may contain certa
14、in mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the publication 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 requirement
15、s. The use of such words does not suggest that compliance with the publication is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this publication may involve the use of a claimed Intellectual Property Right. ITU takes
16、no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the publication development process. As of the date of approval of this publication, ITU had not received notice of intellectual property, prot
17、ected by patents, which may be required to implement this publication. 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 2016 All rights reserved. No part of
18、this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. G series Supplement 39 (02/2016) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Terms and definitions . 3 4 Abbreviations and acronyms 3 5 Definition of spectral bands 7 5.1 General c
19、onsiderations . 7 5.2 Allocation of spectral bands for single-mode fibre systems 7 5.3 Bands for multimode fibre systems 9 6 Parameters of system elements . 10 6.1 Line coding . 10 6.2 Transmitters 10 6.3 Optical amplifiers . 12 6.4 Optical path 13 6.5 Receivers 15 7 Line coding considerations . 16
20、7.1 Overview of various line coding schemes 17 7.2 Return to zero (RZ) implementation 19 7.3 ODB and RZ-AMI line coding format . 22 7.4 Differential phase shift keying (DPSK) modulation implementations . 24 7.5 Differential quadrature phase shift keying (DQPSK) implementation 26 7.6 DP-QPSK (PM-QPSK
21、) implementation 26 7.7 Optical orthogonal frequency division multiplexing (O-OFDM) 26 7.8 Nyquist WDM 30 7.9 Polarization division multiplexing binary phase shift keying (PDM-BPSK) implementation . 32 7.10 Quadrature amplitude modulation (QAM) implementation . 32 7.11 System impairment consideratio
22、ns . 34 7.12 Multi-dimensional modulation formats 37 8 Optical network topology . 42 8.1 Topological structures 42 9 “Worst-case“ system design 44 9.1 Power budget concatenation . 44 9.2 Chromatic dispersion 46 9.3 Polarization mode dispersion . 56 9.4 BER and Q factor . 56 9.5 Noise concatenation 6
23、0 9.6 Optical crosstalk . 65 9.7 Concatenation of non-linear effects Computational approach 70 iv G series Supplement 39 (02/2016) Page 10 Statistical system design . 75 10.1 Generic methodology . 75 10.2 Statistical design of loss . 78 10.3 Statistical design of chromatic dispersion 84 10.4 Statist
24、ical design of polarization mode dispersion . 90 11 Forward error correction (FEC) 91 11.1 In-band FEC in SDH systems . 92 11.2 Out-of-band FEC in optical transport networks (OTNs) 92 11.3 Coding gain and net coding gain (NCG) 92 11.4 HD-FEC and SD-FEC applications 94 11.5 Statistical assumption for
25、 coding gain and NCG . 95 11.6 Candidates for parameter relaxation . 96 11.7 Candidates for improvement of system characteristics 97 12 Physical layer transverse and longitudinal compatibility . 97 12.1 Physical layer transverse compatibility 98 12.2 Physical layer longitudinal compatibility . 99 12
26、.3 Joint engineering 100 13 Switched optical network design considerations 100 14 Best practices for optical power safety . 101 14.1 Viewing 101 14.2 Fibre ends . 101 14.3 Ribbon fibres 102 14.4 Test cords 102 14.5 Fibre bends . 102 14.6 Board extenders 102 14.7 Maintenance . 102 14.8 Test equipment
27、 . 102 14.9 Modification . 102 14.10 Key control . 102 14.11 Labels . 102 14.12 Signs . 102 14.13 Alarms 102 14.14 Raman amplified systems . 103 Appendix I Pulse broadening due to chromatic dispersion . 104 I.1 Purpose . 104 I.2 General published result . 104 I.3 Change of notation . 104 I.4 Simplif
28、ication for a particular case . 105 I.5 Pulse broadening related to bit rate 106 G series Supplement 39 (02/2016) v Page I.6 Value of the shape factor 107 I.7 General result and practical units . 107 Bibliography. 109 G series Supplement 39 (02/2016) 1 Supplement 39 to ITU-T G-series Recommendations
29、 Optical system design and engineering considerations 1 Scope This Supplement is not a Recommendation and does not have the status of a standard. In case of conflict between the material contained in this Supplement and the material of the relevant Recommendations, the latter always prevails. This S
30、upplement should not be used as a normative reference; only the relevant Recommendations can be referenced. This Supplement describes design and engineering considerations for unamplified and amplified single-channel and multichannel digital optical line systems supporting plesiochronous digital hie
31、rarchy (PDH), synchronous digital hierarchy (SDH) and optical transport network (OTN) signals in intra-office, inter-office and long-haul terrestrial networks. One intent of this Supplement is to consolidate and expand on related material that is currently included in several Recommendations, includ
32、ing ITU-T G.691, ITU-T G.692, ITU-T G.955, ITU-T G. 957 and ITU-T G.959.1. This Supplement is also intended to allow a better correlation of the specifications of the fibre, components and system interface Recommendations currently developed in ITU-T. 2 References ITU-T G.650.1 Recommendation ITU-T
33、G.650.1 (2010), Definitions and test methods for linear, deterministic attributes of single-mode fibre and cable. ITU-T G.650.2 Recommendation ITU-T G.650.2 (2015), Definitions and test methods for statistical and non-linear related attributes of single-mode fibre and cable. ITU-T G.652 Recommendati
34、on ITU-T G.652 (2009), Characteristics of a single-mode optical fibre and cable. ITU-T G.653 Recommendation ITU-T G.653 (2010), Characteristics of a dispersion-shifted, single-mode optical fibre and cable. ITU-T G.654 Recommendation ITU-T G.654 (2012), Characteristics of a cut-off shifted single-mod
35、e optical fibre and cable. ITU-T G.655 Recommendation ITU-T G.655 (2009), Characteristics of a non-zero dispersion-shifted single-mode optical fibre and cable. ITU-T G.661 Recommendation ITU-T G.661 (2007), Definitions and test methods for the relevant generic parameters of optical amplifier devices
36、 and subsystems. ITU-T G.662 Recommendation ITU-T G.662 (2005), Generic characteristics of optical amplifier devices and subsystems. ITU-T G.663 Recommendation ITU-T G.663 (2011), Application-related aspects of optical amplifier devices and subsystems. ITU-T G.671 Recommendation ITU-T G.671 (2012),
37、Transmission characteristics of optical components and subsystems. ITU-T G.691 Recommendation ITU-T G.691 (2006), Optical interfaces for single channel STM-64 and other SDH systems with optical amplifiers. ITU-T G.692 Recommendation ITU-T G.692 (1998), Optical interfaces for multichannel systems wit
38、h optical amplifiers. 2 G series Supplement 39 (02/2016) ITU-T G.693 Recommendation ITU-T G.693 (2009), Optical interfaces for intra-office systems. ITU-T G.694.1 Recommendation ITU-T G.694.1 (2012), Spectral grids for WDM applications: DWDM frequency grid. ITU-T G.694.2 Recommendation ITU-T G.694.2
39、 (2003), Spectral grids for WDM applications: CWDM wavelength grid. ITU-T G.695 Recommendation ITU-T G.695 (2015), Optical interfaces for coarse wavelength division multiplexing applications. ITU-T G.697 Recommendation ITU-T G.697 (2012), Optical monitoring for dense wavelength division multiplexing
40、 systems. ITU-T G.698.1 Recommendation ITU-T G.698.1 (2009), Multichannel DWDM applications with single-channel optical interfaces. ITU-T G.698.2 Recommendation ITU-T G.698.2 (2009), Amplified multichannel dense wavelength division multiplexing applications with single channel optical interfaces. IT
41、U-T G.707 Recommendation ITU-T G.707/Y.1322 (2007), Network node interface for the synchronous digital hierarchy (SDH). ITU-T G.709 Recommendation ITU-T G.709/Y.1331 (2012), Interfaces for the optical transport network. ITU-T G.798 Recommendation ITU-T G.798 (2012), Characteristics of optical transp
42、ort network hierarchy equipment functional blocks. 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 performance parameters and
43、 objectives for international, constant bit-rate synchronous digital paths. ITU-T G.872 Recommendation ITU-T G.872 (2012), Architecture of optical transport networks. 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
44、 fibre cables. ITU-T G.957 Recommendation ITU-T G.957 (2006), Optical interfaces for equipments and systems 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.975 Recommendation ITU-T G.975 (2
45、000), Forward error correction for submarine systems. ITU-T G.983.1 Recommendation ITU-T G.983.1 (2005), Broadband optical access systems based on Passive Optical Networks (PON). ITU-T G.8080 Recommendation ITU-T G.8080/Y.1304 (2012), Architecture for the automatically switched optical network. ITU-
46、T G.8201 Recommendation ITU-T G.8201 (2011), Error performance parameters and objectives for multi-operator international paths within optical transport networks. G series Supplement 39 (02/2016) 3 ITU-T L.302 Recommendation ITU-T L.302/L.40 (2000), Optical fibre outside plant maintenance support, m
47、onitoring and testing system. ITU-T L.301 Recommendation ITU-T L.301/L.41 (2000), Maintenance wavelength on fibres carrying signals. IEC 61291-4 IEC 61291-4 (2011), Optical amplifiers Part 4: Multichannel applications Performance specification template. IEC/TR 61282-3 IEC/TR 61282-3 (2006), Fibre op
48、tic communication system design guides Part 3: Calculation of link polarization mode dispersion. IEC/TR 61292-3 IEC/TR 61292-3 (2003), Optical amplifiers Part 3: Classification, characteristics and applications. 3 Terms and definitions Formal definitions are found in the Recommendations referenced i
49、n clause 2. 4 Abbreviations and acronyms This Supplement uses the following abbreviations and acronyms: 1R Regeneration of power 2R Regeneration of power and shape 3D-Simplex 3-Dimensional Simplex 3R Regeneration of power, shape and timing 6PolSK-QPSK 6-Polarization Shift Keying QPSK ADC Analogue-to-Digital Converter ADM Add/Drop Multiplexer APR Automatic Power Reduction ASE Amplified Spontaneous Emission ASK Amplitude Sh
