ITU-T G 692-1998 Optical Interfaces for Multichannel Systems with Optical Amplifiers - Series G Transmission Systems and Media Digital Systems and Networks - Transmission Media Chapo.pdf

1、STD=ITU-T RECMN GOb92-ENGL L998 m 48b259L Ob54895 558 m INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU G.692 (I 0198) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Transmission media characteristics - Characteristics of optical co

2、mponents and sub-systems Optical interfaces for multichannel systems with optical amplifiers ITU-T Recommendation G.692 (Previously CCllT Recommendation) ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS lNTER

3、NATlONAL ANALOGUE CARRIER SYSTEM GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER- TRANSMISSION SYSTEMS G.100-G.199 G.200-G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE G.300-G.399 SYSTEMS ON METALLIC LINES GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE G.400-G

4、.449 WITH METALLIC LINES SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY TESTING EQUIPMENTS TRANSMISSION MEDIA CHARACTERISTICS General G.450-G.499 G.600-G.609 Symmetric cable pairs G.610-G.619 Land coaxial cable pairs G.620-G.629 Submar

5、ine cables G.630-G.649 Optical fibre cables G.650-G.659 DIGITAL TRANSMISSION SYSTEMS TERMINAL EQUIPMENTS DIGITAL NETWORKS DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.700-G.799 G.800-G.899 G.900-G.999 For further details, please refer to ITU-T List of Recommendations. ITU-T RECOMMENDATION G.692 OPTICA

6、L INTERFACES FOR MULTICHANNEL SYSTEMS WITH OPTICAL AMPLIFIERS Summary This Recommendation specifies multichannel optical line system interfaces for the purpose of providing future transverse compatibility among such systems. This Recommendation defines interface parameters for systems of four, eight

7、 and sixteen channels operating at bit rates of up to STM-16 on fibres, as described in Recommendations G.652, G.653 and G.655 with nominal span lengths of 80 km, 120 km and 160 km and target distances between regenerators of up to 640 km. A frequency grid anchored at 193.1 THz with interchannel spa

8、cings at integer multiples of 50 GHz and 100 GHz is specified as the basis for selecting channel central frequencies. Source ITU-T Recommendation G.692 was prepared by ITU-T Study Group 15 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 23rd of October 1998. Recommendat

9、ion G.692 (10/98) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating a

10、nd tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecornmunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn,

11、 produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basi

12、s with IS0 and IEC. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation

13、of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU 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 o

14、f the date of approval of this Recommendation, the ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged t

15、o consult the TSB patent database. O ITU 1999 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 Recommendation 6.692 (10/98) CONTEN

16、TS 1 Scope i 2 References 2 3 Terminology . 2 4 Abbreviations . 3 5 Classification of optical interfaces . 5.1 Appllcatlons 5.1.1 Application codes for systems without line amplifiers . 5.1.2 Application codes for systems with line amplifiers 5.2 Implementation . 5.2.1 Reference configurations . 5.2

17、.2 Optical supervisory channel implementations 6 Parameter definitions 6.1 Individual transmitter outputs . 6.1.1 Spectral characteristics 6.1.2 Mean launched power . 6.1.3 Extinction ratio 6.1.4 Eye pattern mask . 6.1.5 Central frequency 6.1.7 Central frequency deviation 6.2 Individual channel inpu

18、t ports 6.3.1 Optical transmit-side crosstalk 6.3.2 Channel output power . 6.3.3 Total launched power 6.3.4 Channel optical signal-to-noise ratio . 6.1.6 Channel spacing 6.3 Optical interface at points MPI-S and S 6.3.5 Maximum channel power difference at point MPI-S or point S 6.4 Optical path 6.4.

19、1 Attenuation 6.4.2 Dispersion 6.4.3 Reflections . 6.5 Optical line amplifier parameters . 6.5.1 Multichannel gain variation 6.5.2 Multichannel gain tilt 6.5.3 Multichannel gain-change difference 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 9 9 9 9 10 10 10 10 10 . Recommendation G.692 (10198) 111 6.6 6.7 6.8 6.9

20、7 6.5.4 Total received power . 6.5.5 Total launched power 6.5.6 Signal spontaneous noise figure 6.6.1 Mean channel input power 6.6.3 Channel optical signal-to-noise ratio . 6.6.5 Maximum channel power difference at point MPI-R or at point R Individual channel output ports Optical interface at points

21、 MPI-R and R . 6.6.2 Mean total input power . 6.6.4 Optical crosstalk at points MPI-R and 6.7.1 Optical crosstalk at individual channel output ports . Individual receiver inputs . 6.8.1 Receiver sensitivity . 6.8.2 Receiver overload 6.8.3 Optical path penalty 6.8.4 Receiver reflectance 6.8.5 Optical

22、 signal-to-noise ratio 6.8.6 Receiver wavelength range . Optical supervisory channel parameters . 6.9.1 Optical supervisory channel wavelength . Optical interface parameter values . Annex A . Nominal central frequencies Annex B . Alternative optical supervisory channel approaches . B.l OSC at 1480 n

23、m . B.2 OSC in 1310 nm band B.3 OSC within EDFA gain bandwidth Appendix I . Methodology for derivation of optical power levels . I . 1 Channel power I . 1.1 Minimum channel power I . 1.2 Maximum channel power I . 1.3 Maximum range for channel power 1.2 Maximum total power Appendix II . Selection of

24、the minimum channel spacing and grid reference fiequency for the WDM plan 11.1 50 GHz1100 GHz spacing and 193.10 THz reference Page 10 10 10 10 10 10 10 11 11 11 11 11 11 11 11 11 11 12 12 12 12 14 16 16 16 16 17 17 17 18 18 19 19 19 iv Recommendation G.692 (10/98) STDmITU-T RECMN Gmb92-ENGL L978 48

25、62591 Ob54701 b8L = 11.2 Absolute frequency reference (AFR) 11.2.1 AFR accuracy 11.2.2 AFR stability . Appendix III . Suggested channel frequency allocations for applications on G.652/G.655 fibres . Appendix IV . Suggested channel frequency allocations for applications on G.653 fibres . Appendix V .

26、 A channel-allocation methodology for applications on G.653 fibre based on unequal channel spacing . V . 1 How to determine unequally-spaced channel frequencies V . 1 . 1 Basic design conditions . V . 1.2 Determination of frequency slot V . 1.3 Required optical bandwidth for unequally spaced frequen

27、cy allocation . V.2 Unequally spaced channel frequency allocation with 25 GHz frequency slot . V.3 Unequally spaced channel frequency allocation with 50 GHz frequency slot . V.4 Unequal channel frequency allocation with 1 O0 GHz frequency slot V.5 Impacts of unequal spacing on other parameters V.5.1

28、 Frequency deviation for unequal spacing with frequency offset . V.5.2 Power Levels . V.6 Bibliography . Appendix VI . Use of pre-equalisation at MPI-S Appendix VI1 . Extension of G.692 to include bidirectional WDM transmission . Appendix VI11 . Extension of G.692 to include 16- and 32- or more chan

29、nel transmission Appendix IX . Extension of G.692 to include STM-64 bit-rate . Page 19 20 20 20 21 23 24 24 25 26 27 27 28 28 28 28 28 29 29 30 31 Recommendation G.692 (10/98) V I Recommendation G.692 OPTICAL INTERFACES FOR MULTICHANNEL SYSTEMS WITH OPTICAL AMPLIFIERS (Geneva, 1998) 1 Scope This Rec

30、ommendation applies to optical interfaces for multichannel optical line systems with optical amplifiers for terrestrial long-haul applications. This Recommendation defines and provides values for optical interface parameters of interoffice and long-haul systems with target lengths up to 160 km witho

31、ut line amplifiers and with target lengths up to 640 km with optical line amplifiers. Descriptions of system reference configurations and their constituent functional blocks are contained in Recommendation G.68 1. The purpose of this Recommendation is to provide optical amplifier specifications for

32、SDH and optical amplifier equipment towards future realisation of transverse compatible multichannel systems. Not all specifications required to obtain full transverse compatible systems could be finalised at the present stage of development. However, because of industry interest and emerging implem

33、entations, this initial version is issued. A complete specification is left to future versions of this Recommendation. This Recommendation applies principally to point-to-point multichannel systems. Specific issues of optical add-drop are not considered. This Recommendation is envisioned to describe

34、 optical line systems that include the following features: D maximum number of channels: 4, 8, 16 , 32 or more; D signal channel types: STM-4, STM-16, or STM-64; transmission over a single fibre: unidirectional or bidirectional. Given evolving technologies and markets, some aspects of the features d

35、escribed above are not fully characterised at this time, and are marked for further study. Some aspects of 16 and 32 channel systems, STM-64 and possibly bidirectional transmission are for further study. Some system aspects regarding bidirectional transmission (Appendix VII), regarding 16- and 32-ch

36、annel transmission (Appendix VIII) and regarding STM-64 transmission (Appendix IX) are contained in the indicated appendices. This Recommendation has been prepared from the experience with Erbium-Doped (silica-based) Fibre Amplifiers (EDFA), operating in the 1550 nm wavelength region. Other optical

37、amplifiers operating at different wavelength regions, including the 13 10 nm region, are not intended to be excluded from this Recommendation. Recommendation G.692 (10/98) 1 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text

38、, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent editio

39、n of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. - ITU-T Recommendation G.652 (1 997), Characteristics of a single-mode opticaljbre cable. - ITU-T Recommendation G.653 (1 997), Characteristics of a dispersion-shif

40、ted single-mode - ITU-T Recommendation G.655 (1996), Characterisation of a non-zero dispersion shijled - ITU-T Recommendation G.661 (1998), Definition and test methods for the relevant generic - ITU-T Recommendation G.662 (1 998), Generic characteristics of optical ampliJer devices - ITU-T Recommend

41、ation G.663 (1 996), Application related aspects of opticalfibre amplifier - ITU-T Recommendation G.671 (1 996), Transmission characteristics of passive optical - ITU-T Recommendation G.68 1 (1 996), Functional characteristics of interofice and long- - ITU-T Recommendation G.707 (1996), Network node

42、 interface for the Synchronous Digital - ITU-T Recommendation G.783 (1 997), Characteristics of Synchronous Digital Hierarchy - ITU-T Recommendation G.955 (1 996), Digital line systems based on the 1544 kbit/s and the - ITU-T Recommendation G.957 (1995), Optical interfaces for equipments and systems

43、 - IEC Publication 60825-1 (1993), Safety of laser products - Part I: Equipment classljkation, - IEC Publication 6 1291 -4 Ed. 1 .O (working progress), Performance specijkation template on opticaljbre cable. single-mode optical fibre cable. parameters of optical ampliJier devices and subsystems. and

44、 subsystems. devices and sub-systems. components. haul line systems using optical ampliJiers, including optical multiplexing. , Hierarchy (SDH). (SDH) equipmentfinctional blocks. 2048 kbit/s hierarchy on opticalfibre cables. relating to the synchronous digital hierarchy. requirements and users guide

45、. optical amplfler-s - Part 4: Opticalfibre amplifiers for multichannel applications. 3 Terminology This Recommendation defines the following terms: 3.1 Optical Supervisory Channel (OSC): A channel that is accessed at each optical line amplifier site that is used for maintenance purposes including (

46、but not limited to) remote site alarm reporting, communication necessary for fault location, and ordenvire. The Optical Supervisory Channel is not used to carry payload traffic. 2 Recommendation G.692 (10/98) 3.2 main (optical) path: The fibre plant between the MPI-S point of the transmitter equipme

47、nt and the MPI-R point of the receiver equipment. The main path does not include any auxiliary paths. 3.3 main path interfaces: The interfaces to the fibre plant specified in this Recommendation. 4 Abbreviations This Recommendation uses the following abbreviations: AFR Absolute Frequency Reference A

48、SE Amplified Spontaneous Emission BER Bit-Error Ratio EDFA Erbium-Doped Fibre Amplifier FWM Four-Wave Mixing MPI Multiple Path Interference MPI-R Main Path Interface at the Receiver MPI-S Main Path Interface at the Transmitter NF Noise Figure OA Optical Amplifier OD Optical Demultiplexer OE0 Optical

49、-Electrical-Optical Converter OM Optical Multiplexer OSC Optical Supervisory Channel OSNR Optical Signal-to-Noise Ratio PMD Polarisation Mode Dispersion Rx Optical Receiver SBS Stimulated Brillouin Scattering SDH Synchronous Digital Hierarchy SNR Signal-to-Noise Ratio SPM Self Phase Modulation STM-N Synchronous Transport Module Level N TX Optical Transmitter WDM Wavelength Division Multiplexing XPM Cross-Phase Modulation 5 Classification of optical interfaces 5.1 Applications This Recommendation addresses multichannel systems for terrestrial long-haul applications with to