1、 International Telecommunication Union ITU-T G.698.3TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (02/2012) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Transmission media and optical systems characteristics Characteristics of optical systems Multichannel seeded DWDM appl
2、ications with single-channel optical interfaces Recommendation ITU-T G.698.3 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 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 o
5、ptical 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
6、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.698.3 (02/2012) i Recommendation ITU-T G.698.3
7、 Multichannel seeded DWDM applications with single-channel optical interfaces Summary Recommendation ITU-T G.698.3 provides optical parameter values for physical layer interfaces of seeded dense wavelength division multiplexing (DWDM) systems primarily intended for metro applications. Applications a
8、re defined using optical interface parameters and values for single-channel and multichannel interfaces of seeded DWDM multichannel optical systems in point-to-point applications. This Recommendation uses a system architecture comprising a head-end, connecting to the tail-end equipment (TEE) through
9、 a black link. The head-end houses a set of transmitters and receivers and an optical multiplexer and demultiplexer (OD/OM) in addition to a seed signal source. A single bidirectional fibre is used to connect the head-end to the passive OD/OM. Connection between OD/OM and remote TEE is also bidirect
10、ional. At the tail-end, all transmitters use a seed signal to lock to the desired transmission wavelength. The initial version of this Recommendation includes seeded DWDM application at 1.25 Gbit/s with 100-GHz channel frequency spacing. History Edition Recommendation Approval Study Group 1.0 ITU-T
11、G.698.3 2012-02-13 15 ii Rec. ITU-T G.698.3 (02/2012) 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
12、 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 worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, es
13、tablishes 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 in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary
14、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 administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the
15、 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 provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equival
16、ents 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 RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a clai
17、med 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 outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had r
18、eceived 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 latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T
19、/ipr/. ITU 2012 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.698.3 (02/2012) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Terms and definitions . 2 3.1 Terms defined elsewhere 2 3.2 Te
20、rms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Classification of optical interfaces 3 5.1 Applications 3 5.2 Reference points . 3 5.3 Nomenclature . 4 5.4 Interfaces at the reference points MPI-SM, MPI-RM, SSand RS 5 6 Transverse compatibility 5 7 Parameter definitions 5 7.1
21、 General information 7 7.2 Interface at point SSor MPI-SM. 7 7.3 Optical path parameters from MPI-SMto RSor SSto MPI-RM . 9 7.4 Interface at point RSor MPI-RM 10 8 Parameter values . 11 9 Optical safety considerations 13 Appendix I Derivation of off-grid channel frequencies 14 Bibliography. 15 Rec.
22、ITU-T G.698.3 (02/2012) 1 Recommendation ITU-T G.698.3 Multichannel seeded DWDM applications with single-channel optical interfaces 1 Scope The purpose of this Recommendation is to provide optical interface specifications towards the realization of transversely compatible seeded dense wavelength div
23、ision multiplexing (DWDM) systems primarily intended for metro applications. This Recommendation defines and provides values for optical interface parameters of point-to-point seeded DWDM applications (with maximum transmission distance of about 40 km) on single-mode optical fibres through the use o
24、f the “black link“ approach. Applications containing amplifiers within the black link are outside the scope of this Recommendation. This Recommendation describes seeded DWDM systems that include the following features: Channel frequency spacing: 100 GHz; Bit rate of signal channel: up to 1.25 Gbit/s
25、. Specifications are organized according to application codes. 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 valid.
26、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 Recommendations is
27、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.652 Recommendation ITU-T G.652 (2005), Characteristics of a single-mode optical fibre and cable. ITU-T G.664 Recommendation ITU-T G.664 (20
28、06), Optical safety procedures and requirements for optical transport systems. ITU-T G.671 Recommendation ITU-T G.671 (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 s
29、ystems with optical amplifiers. ITU-T G.694.1 Recommendation ITU-T G.694.1 (2002), Spectral grids for WDM applications: DWDM frequency grid. ITU-T G.698.1 Recommendation ITU-T G.698.1 (2009), Multichannel DWDM applications with single-channel optical interfaces. ITU-T G.709 Recommendation ITU-T G.70
30、9/Y.1331 (2009), 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 Recommendation ITU-T G.959.1 (2009), Optical transport network physical layer
31、 interfaces. 2 Rec. ITU-T G.698.3 (02/2012) IEC 60825-1 IEC 60825-1 (2007), Safety of laser products Part 1: Equipment classification and requirements. IEC 60825-2 IEC 60825-2 (2010), Safety of laser products Part 2: Safety of optical fibre communication systems (OFCS). 3 Terms and definitions 3.1 T
32、erms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 Terms defined in ITU-T G.671: channel insertion loss channel spacing dense wavelength division multiplexing (DWDM) differential group delay reflectance ripple 3.1.2 Term defined in ITU-T G.694.1: frequency g
33、rid 3.1.3 Term defined in ITU-T G.709: completely standardized OTUk (OTUk) 3.1.4 Terms defined in ITU-T G.957: joint engineering receiver sensitivity transverse compatibility 3.1.5 Terms defined in ITU-T G.959.1: optical tributary signal optical tributary signal class NRZ 1.25G 3.2 Terms defined in
34、this Recommendation This Recommendation does not define any terms. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: BER Bit Error Ratio BLS Broadband Light Source DOP Degree of Polarization DWDM Dense Wavelength Division Multiplexing MPI-RM Multichannel
35、 reference point at the head-end aggregate inputMPI-SM Multichannel reference point at the head-end aggregate output MWS Multi-Wavelength Source Rec. ITU-T G.698.3 (02/2012) 3 NA Not Applicable NRZ Non-Return to Zero OD Optical Demultiplexer OM Optical Multiplexer OTUk Completely standardized optica
36、l channel transport unit k RIN Relative Intensity Noise RSSingle-channel reference point at the DWDM network element tributary output SLED Super-luminescent Light Emitting Diode SSSingle-channel reference point at the DWDM network element tributary input TEE Tail-End Equipment WDM Wavelength Divisio
37、n Multiplexing 5 Classification of optical interfaces 5.1 Applications This Recommendation provides the physical layer parameters and values for single-channel and multichannel interfaces of seeded DWDM multichannel optical systems in physical point-to-point applications. These DWDM systems are prim
38、arily intended to be used in metropolitan area networks for a variety of clients, services, and protocols. The specification method in this Recommendation uses a “black link“ approach which means that optical interface parameters for only (single-channel) optical tributary signals are specified at t
39、he tail-end equipment (TEE). Additional specifications are provided for the black link parameters such as maximum attenuation, chromatic dispersion, ripple and polarization mode dispersion. This approach enables transverse compatibility at the single-channel point using a direct wavelength-multiplex
40、ing configuration, and also transverse compatibility at the head-end multichannel point as shown in Figure 5-1. This Recommendation only considers DWDM applications where the black link does not contain optical amplifiers. 5.2 Reference points Figure 5-1 shows a set of reference points that are defi
41、ned in this Recommendation. G.698.3(12)_F5-1RxTx11RxTx22 OD/OMRxTxNNHead-endSeed sourceMPI-Rfor signalsgoing MMPI-Sfor signalsgoing MOD/OMBlack linkR for signalsgoing SS for signalsgoing SR SR SS SS SRxTx11RxTx22RxTxNNTail-end.Figure 5-1 Reference diagram 4 Rec. ITU-T G.698.3 (02/2012) The system ar
42、chitecture comprises a head-end, connecting to the TEE through a black link. The head-end houses a set of transmitters and receivers and an OD/OM in addition to a seed signal source. The seed source can be implemented in a number of ways. These include pumped Erbium-doped fibre, a super-luminescent
43、light emitting diode (SLED) or a multi-wavelength laser source. A single bidirectional fibre is used to connect the head-end to the passive OD/OM. Connection between OD/OM and remote TEE is also bidirectional. The OD/OM is considered to be part of the black link. The black link does not include any
44、optical amplifiers. At the tail-end, all transmitters use a seed signal to lock to the desired transmission wavelength. The reference points in Figure 5-1 are defined as follows: MPI-SMis a multichannel reference point at the head-end aggregate output; MPI-RMis a multichannel reference point at the
45、head-end aggregate input; SSis a single-channel reference point at the TEE output; RSis a single-channel reference point at the TEE input. At the MPI-SMinterface, multichannel data signals and a broadband seed signal are transmitted by the head-end. At the RSinterface two types of single channel sig
46、nals pass through towards the TEE; a data signal and a seed signal to lock the transmission in the tail-end to head-end direction. At the SSinterface, a single channel signal is transmitted by the TEE whose wavelength is locked to the incoming seed signal. At the MPI-RMinterface, a multichannel sign
47、al is received by the head-end. 5.3 Nomenclature The application code identifies the network, implementation, and architectural characteristics of an application. The application code notation is constructed as follows: SDcW-ytz where: SD is the indicator of Seeded DWDM applications. c is the channe
48、l spacing in GHz. W is a letter indicating the span distance. In the current version of this Recommendation, the only value used is: S indicating short-haul; y indicates the highest class of optical tributary signal supported. In the current version of this Recommendation, the only value used is: 0
49、indicating NRZ 1.25G; t indicates the configuration supported by the application code. In the current version of this Recommendation, the only value used is: D indicating that the black link does not contain any optical amplifiers. z indicates the fibre types. In the current version of this Recommendation, the only value used is: 2 indicating ITU-T G.652 fibre; Rec. ITU-T G.698.3 (02/2012) 5 5.4 Interfaces at the reference points MPI-SM, MPI-RM, SSand RSThe interf
