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.989.2 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 2 (08/2017) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Optical line systems for local an
2、d access networks 40-Gigabit-capable passive optical networks 2 (NG-PON2): Physical media dependent (PMD) layer specification Amendment 2 Recommendation ITU-T G.989.2 (2014) Amendment 2 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHON
3、E CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-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-
4、RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF 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 L
5、INE SYSTEM G.900G.999 General G.900G.909 Parameters for optical fibre cable systems G.910G.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
6、 FDM transmission bearers G.940G.949 Digital line systems G.950G.959 Digital section and digital 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.
7、999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.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 t
8、o the list of ITU-T Recommendations. Rec. ITU-T G.989.2 (2014)/Amd.2 (08/2017) i Recommendation ITU-T G.989.2 40-Gigabit-capable passive optical networks 2 (NG-PON2): Physical media dependent (PMD) layer specification Amendment 2 Summary Recommendation ITU-T G.989.2 specifies the physical media depe
9、ndent (PMD) layer requirements for a passive optical network (PON) system with a nominal aggregate capacity of 40 Gbit/s in the downstream direction and 10 Gbit/s in the upstream direction, hereinafter referred to as NG-PON2. NG-PON2 is a flexible optical fibre access network capable of supporting t
10、he bandwidth requirements of mobile backhaul, business and residential services. Furthermore, this Recommendation describes optional configurations, to extend beyond this nominal capacity, as the ITU-T G.989 series of Recommendations allows for multiple upstream and downstream line rates. The NG-PON
11、2 wavelength plan is defined to enable the coexistence through wavelength overlay with legacy PON systems (see ITU-T G.989.1). The transmission convergence (TC) layer is based on Recommendation ITU-T G.987.3, with unique modifications for NG-PON2 captured in Recommendation ITU-T G.989.3. The optical
12、 network unit (ONU) management and control interface (OMCI) specifications are described in Recommendation ITU-T G.988 for NG-PON2 extensions. This Recommendation specifies the characteristics of hybrid time and wavelength division multiplexing (TWDM) channels, referred to as TWDM PON. The character
13、istics of optional, tunable point-to-point wavelength overlay channels are also described, referred to as point-to-point wavelength division multiplexing (PtP WDM) PON. The TWDM PON described in this Recommendation represents a further development from the systems described in the ITU-T G.984 and IT
14、U-T G.987 series of Recommendations. To the greatest extent possible, this Recommendation retains the requirements of ITU-T G.984.1 and ITU-T G.987.1 to ensure maximal reuse of existing technology and compatibility with deployed optical access systems and optical fibre infrastructure. Amendments 1 a
15、nd 2 continue the maintenance and evolution of physical media dependent (PMD) layer specification. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G.989.2 2014-12-05 15 11.1002/1000/12097 1.1 ITU-T G.989.2 (2014) Amd. 1 2016-04-13 15 11.1002/1000/12556 1.2 ITU-T G.989.2 (201
16、4) Amd. 2 2017-08-13 15 11.1002/1000/13292 _ * 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-T G.989.2 (2014)/Amd.2 (08/2017) F
17、OREWORD 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 responsible for study
18、ing 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 the ITU-T study group
19、s 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 collaborative basis with IS
20、O 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 mandatory provision
21、s (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 requirements. The use of such
22、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 takes no position c
23、oncerning 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 property, protected by pa
24、tents, 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 2017 All rights reserved. No part of this pub
25、lication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.989.2 (2014)/Amd.2 (08/2017) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 3 4 Abbreviations and acronyms 3 5 Conventions 3 6 Architecture of the optical access netw
26、ork . 3 6.1 Physical grouping of logical functions . 4 6.2 ODN optical path loss (OPL) classes . 4 6.3 Fibre distance classes . 5 7 Services . 5 8 User network interface and service node interface . 5 9 Common optical network requirements 5 9.1 Layered structure of optical network 5 9.2 Wavelength p
27、lans for NG-PON2 5 9.3 Physical media dependent layer requirements . 6 10 Crosstalk-to-signal ratio tolerance for NG-PON2 9 10.1 Wideband X/S tolerance mask definition . 10 10.2 Narrowband TWDM PON X/S tolerance mask . 11 11 TWDM PON PMD layer requirements 14 11.1 PMD layer requirements . 14 11.2 Up
28、stream physical layer overhead 34 Annex A Tunable PtP WDM PON PMD layer requirements . 35 A.1 PMD layer requirements . 36 Annex B Auxiliary management and control channel 55 B.1 Introduction 55 B.2 Transparent AMCC 55 Annex C Low loss (LL) PtP WDM PON PMD layer requirements . 57 C.1 PMD layer requir
29、ements . 57 Annex D ONU power levelling 75 D.1 Interaction between NG-PON2 PMD layer and TC layer 75 D.2 Power levelling (PL) mechanism at ONU transmitter . 75 D.3 ONU autonomous power levelling . 75 D.4 OOC and OOB PSD relaxation 77 D.5 OLT directed ONU power levelling . 77 D.6 ONU troubleshooting
30、considerations . 77 iv Rec. ITU-T G.989.2 (2014)/Amd.2 (08/2017) Page Appendix I Wavelength considerations for NG-PON2, XG-PON1, G-PON and RF video overlay distribution services . 78 Appendix II Physical layer measurements required to support optical layer supervision 79 Appendix III Allocation of t
31、he physical layer overhead time . 82 Appendix IV Jitter budget specifications for TWDM PON . 85 Appendix V Measurement of TWDM PON burst mode acquisition time and burst node eye opening at OLT 86 Appendix VI Nonlinear Raman interactions in optical fibres and mitigation technologies for coexistence o
32、f multiple PONs 87 Appendix VII Cyclic AWG channel grid design examples 92 Appendix VIII Wavelength multiplexer, upstream inter-channel crosstalk, ONU transmitter tuning time considerations, and upstream channel grid example . 93 VIII.1 Wavelength multiplexer . 93 VIII.2 Upstream inter-channel cross
33、talk . 95 VIII.3 ONU transmitter tuning time 99 VIII.4 TWDM PON upstream channel grid examples 101 Appendix IX Alternative line code for Raman mitigation 102 IX.1 8B10B Scheme . 102 IX.2 Miller users of this Recommendation are therefore encouraged to investigate the possibility of applying the most
34、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 Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.652 Recomme
35、ndation ITU-T G.652 (2009), Characteristics of a single-mode optical fibre and cable. ITU-T G.657 Recommendation ITU-T G.657 (2009), Characteristics of a bending-loss insensitive single-mode optical fibre and cable for the access network. ITU-T G.671 Recommendation ITU-T G.671 (2012), Transmission c
36、haracteristics of optical components and subsystems. 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.989.2 (2014)/Amd.2 (08/2017) ITU-T G.698.1 Recommendation ITU-T G.698.1 (2009), Multichannel DWDM applications with single-
37、channel optical interfaces. ITU-T G.698.3 Recommendation ITU-T G.698.3 (2012), Multichannel seeded DWDM applications with single-channel optical interfaces. ITU-T G.707 Recommendation ITU-T G.707/Y.1322 (2009), Network node interface for the synchronous digital hierarchy (SDH). ITU-T G.709 Recommend
38、ation ITU-T G.709/Y.1331 (2012), Interfaces for the optical transport network. ITU-T G.783 Recommendation ITU-T G.783 (2006), Characteristics of synchronous digital hierarchy (SDH) equipment functional blocks. ITU-T G.825 Recommendation ITU-T G.825 (2000), The control of jitter and wander within dig
39、ital networks which are based on the synchronous digital hierarchy (SDH). 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
40、layer interfaces. ITU-T G.982 Recommendation ITU-T G.982 (1996), Optical access networks to support services up to the ISDN primary rate or equivalent bit rates. 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.984.1
41、 Recommendation ITU-T G.984.1 (2008), Gigabit-capable passive optical networks (GPON): General characteristics. ITU-T G.984.2 Recommendation ITU-T G.984.2 (2003), Gigabit-capable Passive Optical Networks (G-PON): Physical Media Dependent (PMD) layer specification. ITU-T G.984.5 Recommendation ITU-T
42、G.984.5 (2007), Gigabit-capable passive optical networks (G-PON): Enhancement band. ITU-T G.987 Recommendation ITU-T G.987 (2010), 10-Gigabit-capable passive optical network (XG-PON) systems: Definitions, abbreviations and acronyms. ITU-T G.987.1 Recommendation ITU-T G.987.1 (2010), 10 Gigabit-capab
43、le passive optical networks (XG-PON): General requirements. ITU-T G.987.2 Recommendation ITU-T G.987.2 (2010), 10-Gigabit-capable passive optical networks (XG-PON): Physical media dependent (PMD) layer specification. ITU-T G.987.3 Recommendation ITU-T G.987.3 (2010), 10-Gigabit-capable passive optic
44、al networks (XG-PON): Transmission convergence (TC) layer specification. ITU-T G.988 Recommendation ITU-T G.988 (2010), ONU management and control interface (OMCI) specification. ITU-T G.989 Recommendation ITU-T G.989 (2015), 40-Gigabit-capable passive optical networks (NG-PON2): Definitions, abbrev
45、iations, and acronyms. ITU-T G.989.1 Recommendation ITU-T G.989.1 (2013), 40-Gigabit-capable passive optical networks (NG-PON2): General requirements. ITU-T G.989.3 Recommendation ITU-T G.989.3 (2015), 40-Gigabit-capable passive optical networks (NG-PON2): Transmission convergence layer specificatio
46、n. Rec. ITU-T G.989.2 (2014)/Amd.2 (08/2017) 3 ITU-T J.185 Recommendation ITU-T J.185 (2012), Transmission equipment for transferring multi-channel television signals over optical access networks by frequency modulation conversion. ITU-T J.186 Recommendation ITU-T J.186 (2008), Transmission equipmen
47、t for multi-channel television signals over optical access networks by sub-carrier multiplexing (SCM). ITU-T L.66 Recommendation ITU-T L.66 (2007), Optical fibre cable maintenance criteria for in-service fibre testing in access networks. 3 Definitions See clause 5 of ITU-T G.989 for conventions. 4 A
48、bbreviations and acronyms See clause 4 of ITU-T G.989 for abbreviations and acronyms. 5 Conventions See clause 5 of ITU-T G.989 for conventions. 6 Architecture of the optical access network Figure 6-1 represents the reference logical architecture for the multi-wavelength NG-PON2 system. A multi-syst
49、em OAN architecture for NG-PON2 coexistence with legacy systems is represented in Figure 5-1 of ITU-T G.989.1. During coexistence, mitigation techniques may be necessary to avoid inter-system impairments, e.g., see Appendix VI and Appendix IX for Raman crosstalk considerations. This architecture allows both point-to-multipoint connectivity (i.e., TWDM PON) and virtual point-to-point connectivity (i.e., PtP WDM PON). Figure 6
