1、 International Telecommunication Union ITU-T G.698.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2009) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Transmission media and optical systems characteristics Characteristics of optical systems Multichannel DWDM application
2、s with single-channel optical interfaces Recommendation ITU-T G.698.1 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.
3、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 AND LINE
4、TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 General G.600G.609 Symmetric cable pairs G.610G.619 Land coaxial cable pairs G.620G.629 Submarine cables G.630G.639 Free space optical systems G.640G.649 Optical fibre cables G.650G.659 Characteristics of optical
5、components and subsystems G.660G.679 Characteristics of optical systems G.680G.699DIGITAL 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 TRANSMI
6、SSION 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.698.1 (11/2009) i Recommendation ITU-T G.698.1 Multic
7、hannel DWDM applications with single-channel optical interfaces Summary Recommendation ITU-T G.698.1 provides optical parameter values for physical layer interfaces of dense wavelength division multiplexing (DWDM) systems primarily intended for metro applications. Applications are defined using opti
8、cal interface parameters at the single-channel connection points between optical transmitters and the optical multiplexer, as well as between optical receivers and the optical demultiplexer in the DWDM system. This Recommendation uses a methodology which fixes the maximum attenuation of the multiple
9、xer/demultiplexer and fibre together and, therefore, does not specify the maximum fibre-link length explicitly. This Recommendation includes unidirectional DWDM applications at 2.5 and 10 Gbit/s with 100-GHz channel frequency spacing, as well as applications at 10 Gbit/s with 50 GHz channel frequenc
10、y spacing. This latest revision of Recommendation ITU-T G.698.1 includes the use of optical add-drop multiplexers (OADMs) within the black link. History Edition Recommendation Approval Study Group 1.0 ITU-T G.698.1 2005-06-29 15 2.0 ITU-T G.698.1 2006-12-14 15 3.0 ITU-T G.698.1 2009-11-13 15 ii Rec.
11、 ITU-T G.698.1 (11/2009) 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-
12、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 stud
13、y 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 on a c
14、ollaborative 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 c
15、ertain 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 requi
16、rements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Righ
17、t. 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 of the date of approval of this Recommendation, ITU had not received notice of intellec
18、tual property, 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 2010 All rights
19、 reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.698.1 (11/2009) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Terms and definitions . 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation
20、. 2 4 Abbreviations and acronyms 2 5 Classification of optical interfaces 3 5.1 Applications 3 5.2 Reference points . 3 5.3 Nomenclature . 6 5.4 Single-channel interfaces at the reference points SSand RS 7 6 Transverse compatibility 8 7 Parameter definitions 9 7.1 General information 9 7.2 Interface
21、 at point SS . 10 7.3 Optical path parameters (single span) from SSto RS . 11 7.4 Interface at point RS . 14 8 Parameter values . 15 9 Optical safety considerations 22 Appendix I Number of OADMs supported in a link 23 I.1 Introduction 23 I.2 Maximum channel insertion loss 23 I.3 Maximum ripple . 23
22、I.4 Maximum chromatic dispersion . 24 I.5 Reflections 24 I.6 Maximum differential group delay . 24 I.7 Maximum interferometric crosstalk . 25 Bibliography. 26 Rec. ITU-T G.698.1 (11/2009) 1 Recommendation ITU-T G.698.1 Multichannel DWDM applications with single-channel optical interfaces 1 Scope The
23、 purpose of this Recommendation is to provide optical interface specifications towards the realization of transversely compatible dense wavelength division multiplexing (DWDM) systems primarily intended for metro applications. This Recommendation defines and provides values for single-channel optica
24、l interface parameters of physical point-to-point and ring DWDM applications (with transmission distance in the range of about 30 km to about 80 km) on single-mode optical fibres through the use of the “black link“ approach. Applications containing amplifiers within the black link are outside of the
25、 scope of this Recommendation. This Recommendation describes DWDM systems that include the following features: Channel frequency spacing: 50 GHz and wider (defined in ITU-T G.694.1); Bit rate of signal channel: up to 10 Gbit/s. Specifications are organized according to application codes. 2 Reference
26、s 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 valid. All Recommendations and other references are subject to revision; users of
27、 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 Recommendations is regularly published. The reference to a document within this Recommendatio
28、n does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.652 Recommendation ITU-T G.652 (2005), Characteristics of a single-mode optical fibre and cable. ITU-T G.653 Recommendation ITU-T G.653 (2006), Characteristics of a dispersion-shifted single-mode optical fibre and
29、 cable. ITU-T G.655 Recommendation ITU-T G.655 (2006), Characteristics of a non-zero dispersion-shifted single-mode optical fibre and cable. ITU-T G.664 Recommendation ITU-T G.664 (2006), Optical safety procedures and requirements for optical transport systems. ITU-T G.671 Recommendation ITU-T G.671
30、 (2009), 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 sy
31、stems with optical amplifiers. ITU-T G.694.1 Recommendation ITU-T G.694.1 (2002), Spectral grids for WDM applications: DWDM frequency grid. 2 Rec. ITU-T G.698.1 (11/2009) ITU-T G.698.2 Recommendation ITU-T G.698.2 (2009), Amplified multichannel dense wavelength division multiplexing applications wit
32、h single channel optical interfaces. ITU-T G.709 Recommendation ITU-T G.709/Y.1331 (2003), Interfaces for the optical transport network (OTN). 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 Rec
33、ommendation ITU-T G.959.1 (2008), Optical transport network physical layer interfaces. 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 sy
34、stems (OFCS). 3 Terms and definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 channel insertion loss ITU-T G. 671 3.1.2 channel spacing ITU-T G.671 3.1.3 completely standardized OTUk (OTUk) ITU-T G.709 3.1.4 dense wavelength division multiple
35、xing (DWDM) device ITU-T G.671 3.1.5 differential group delay ITU-T G. 671 3.1.6 frequency grid ITU-T G.694.1 3.1.7 joint engineering ITU-T G.957 3.1.8 optical tributary signal ITU-T G.959.1 3.1.9 optical tributary signal class NRZ 10G ITU-T G.959.1 3.1.10 optical tributary signal class NRZ 2.5G ITU
36、-T G.959.1 3.1.11 reflectance ITU-T G. 671 3.1.12 ripple ITU-T G.671 3.1.13 transverse compatibility ITU-T G.957 3.2 Terms defined in this Recommendation This Recommendation does not define any terms. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: ASE
37、 Amplified Spontaneous Emission BER Bit Error Ratio DGD Differential Group Delay EX Extinction Ratio Rec. ITU-T G.698.1 (11/2009) 3 FEC Forward Error Correction NA Not Applicable NE Network Element NRZ Non-Return to Zero OA Optical Amplifier OADM Optical Add-Drop Multiplexer OD Optical Demultiplexer
38、 OM Optical Multiplexer ONE Optical Network Element OTUk Completely standardized optical channel transport unit k PMD Polarization Mode Dispersion RPRLink reference point at the DWDM network element aggregate input RPSLink reference point at the DWDM network element aggregate output RSSingle-channel
39、 reference point at the DWDM network element tributary output SSSingle-channel reference point at the DWDM network element tributary input WDM Wavelength Division Multiplexing 5 Classification of optical interfaces 5.1 Applications This Recommendation provides the physical layer parameters and value
40、s for single-channel interfaces of DWDM multichannel optical systems in physical point-to-point and ring applications. These DWDM systems with single-channel interfaces are primarily intended to be used in metropolitan area networks for a variety of clients, services, and protocols. The specificatio
41、n method in this Recommendation uses a “black link“ approach, which means that optical interface parameters for only (single-channel) optical tributary signals are specified. Additional specifications are provided for the black link parameters such as maximum attenuation, chromatic dispersion, rippl
42、e and polarization mode dispersion. This approach enables transverse compatibility at the single-channel point using a direct wavelength-multiplexing configuration. However, it does not enable transverse compatibility at the multichannel points. In this approach, the OM and OD are treated as a singl
43、e set of optical devices and OADMs can be included. This Recommendation only considers DWDM applications where the black link does not contain optical amplifiers. 5.2 Reference points 5.2.1 Unidirectional applications Figure 5-1 shows a set of reference points, for the linear “black link“ approach,
44、for single-channel connection (SSand RS) between transmitters (Tx) and receivers (Rx). Here, the DWDM network elements include an OM and an OD, which are used as a pair with the opposing element, and may also include one or more OADMs. 4 Rec. ITU-T G.698.1 (11/2009) G.698.1(09)_F5-1Tx 1Tx 2Tx NSSSSS
45、SOMRPSDWDM linkOADM ODRPRRx 1Rx 2Rx NRSRSRSSSRSRxXTxYDWDM network elementsFigure 5-1 Linear “black link“ approach As indicated in Figure 5-1, in cases where the transmitter or receiver is some distance from the OM, OD or OADM, the fibre between point SSor RSand the DWDM network element is considered
46、 to be part of the black link. Figure 5-2 shows a corresponding set of reference points for the ring “black link“ approach, for single-channel connection (SSand RS) between transmitters (Tx) and receivers (Rx). Here, the DWDM network elements include two or more OADMs connected in a ring. G.698.1(09
47、)_F5-2SSSSSSDWDM linkRSRSRSRx TxDWDM network elementsTxTxTxRSSSOADMRxRxRxOADMOADMOADMFigure 5-2 Ring “black link“ approach Rec. ITU-T G.698.1 (11/2009) 5 These reference models do not include any optical amplifiers in the DWDM system. The reference points in Figures 5-1 and 5-2 are defined as follow
48、s: SSis a single-channel reference point at the DWDM network element tributary input; RSis a single-channel reference point at the DWDM network element tributary output; RPSis a link reference point at the DWDM network element aggregate output; RPRis a link reference point at the DWDM network elemen
49、t aggregate input. Here, single-channel reference points SSand RSare applied to systems for the (linear or ring) “black link“ approach where every path from SSto its corresponding RSmust comply with the parameter values of the application code. Note that RPSand RPRare only defined to provide information for the fibre link and not to provide signal characteristics at these points. 5.2.2 Bidirectional applications While this Recommendation does not currently contai
