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.987.2 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1 (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 10-Gigabit-capable passive optical networks (XG-PON): Physical media dependent (PMD) layer specification Amendment 1 Recommendation ITU-T G.987.2 (2016) Amendment 1 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE C
3、ONNECTIONS 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-REL
4、AY 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 LINE
5、 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 FD
6、M 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.999
7、 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 to t
8、he list of ITU-T Recommendations. Rec. ITU-T G.987.2 (2016)/Amd.1 (08/2017) i Recommendation ITU-T G.987.2 10-Gigabit-capable passive optical networks (XG-PON): Physical media dependent (PMD) layer specification Amendment 1 Summary Recommendation ITU-T G.987.2 describes the physical layer requiremen
9、ts and specifications for the XG-PON physical media dependent (PMD) layer. Wavelength enhancement bands are described in Recommendation ITU-T G.987.1. The transmission convergence (TC) layer is described in Recommendation ITU-T G.987.3. The ONU management and control interface (OMCI) specifications
10、are described in Recommendation ITU-T G.988. Recommendation ITU-T G.987.2 describes a flexible optical fibre access network capable of supporting the bandwidth requirements of business and residential services. The G.987 series of standards allows for multiple upstream and downstream line rates. Thi
11、s Recommendation currently defines one type of 10-Gigabit-capable passive optical network (XG-PON) system with asymmetric nominal line rate of 9.95328 Gbit/s in the downstream direction and 2.48832 Gbit/s in the upstream direction. This Recommendation describes a system that represents an evolutiona
12、ry development from the systems described in the ITU-T G.984 series. To the greatest extent possible, this Recommendation maintains the requirements of Recommendation ITU-T G.984.1 to ensure maximal continuity with existing systems and optical fibre infrastructure. Amendment 1 continues the maintena
13、nce and evolution of physical media dependent (PMD) layer specifications for XG-PON as defined in this Recommendation. It includes technical updates and corrections for changing references to XG-PON1 to XG-PON, replacing the mask of the eye diagram for ONU transmitter, and correcting the X/S toleran
14、ce mask for ONU. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G.987.2 2010-01-13 15 11.1002/1000/10411 2.0 ITU-T G.987.2 2010-10-07 15 11.1002/1000/10889 2.1 ITU-T G.987.2 (2010) Amd. 1 2012-02-13 15 11.1002/1000/11499 3.0 ITU-T G.987.2 2016-02-26 15 11.1002/1000/12832 3.
15、1 ITU-T G.987.2 (2016) Amd. 1 2017-08-13 15 11.1002/1000/13290 Keywords 10-Gigabit-capable passive optical network, FTTx network, OLT, ONU, optic, optical network terminal (ONT), passive optical network (PON), physical layer interfaces, physical layer requirements, physical layer specification, PMD,
16、 XG-PON. * 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.987.2 (2016)/Amd.1 (08/2017) FOREWORD The International Telecommun
17、ication 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 studying technical, operating and tariff
18、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 groups which, in turn, produce Recommenda
19、tions 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 ISO and IEC. NOTE In this Recommendati
20、on, 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 provisions (to ensure, e.g., interoperability
21、 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 words does not suggest that complian
22、ce 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 concerning the evidence, validity or
23、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 intellectual property, protected by patents, which may be required to
24、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 publication may be reproduced, by a
25、ny means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.987.2 (2016)/Amd.1 (08/2017) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 Architecture of the optical access network . 2 6.1 Classes for optical
26、path loss . 3 6.2 Categories for fibre differential distance 4 7 Services . 4 8 User network interface and service node interface . 4 9 Optical network requirements . 4 9.1 Layered structure of optical network 4 9.2 Physical media dependent layer requirements for the XG-PON 4 10 X/S tolerance of XG-
27、PON ONU 17 10.1 Versatile WDM configuration 17 11 Upstream physical layer overhead 18 Appendix I Examples of wavelength allocation for XG-PON, G-PON and video distribution services 19 Appendix II Physical layer measurements required to support optical layer supervision 20 Appendix III Allocation of
28、the physical layer overhead time . 21 Appendix IV Jitter budget specifications 24 IV.1 The concept of jitter budget 24 IV.2 Definition of test points 25 IV.3 Jitter budget specification for XG-PON . 26 IV.4 Jitter measurements for compliance to budget . 26 Appendix V Measurement of burst mode acquis
29、ition time and burst mode eye opening at OLT . 28 Bibliography. 31 Rec. ITU-T G.987.2 (2016)/Amd.1 (08/2017) 1 Recommendation ITU-T G.987.2 10-Gigabit-capable passive optical networks (XG-PON): Physical media dependent (PMD) layer specification Amendment 1 Editorial note: This is a complete-text pub
30、lication. Modifications introduced by this amendment are shown in revision marks relative to Recommendation ITU-T G.987.2 (2016). 1 Scope This Recommendation pertains to flexible access networks using optical fibre technology. The focus is primarily on a network supporting services with bandwidth re
31、quirements ranging from that of voice to data services running at up to 10 Gbit/s. Also included are broadcast services. This Recommendation describes characteristics of the physical medium dependent (PMD) layer of an optical access network (OAN) with the capability of transporting various services
32、between the user-network interface and the service node interface. The OAN dealt with in this Recommendation enables the network operator to provide a flexible upgrade to meet future customer requirements, in particular, in the area of the optical distribution network (ODN). The ODN considered is ba
33、sed on a point-to-multipoint tree and branch option. 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. All Recomm
34、endations 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 regularly
35、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 (2009), Characteristics of a single-mode optical fibre and cable. ITU-T G.657 Recommendation ITU-T G.657 (2012), Chara
36、cteristics of a bending loss insensitive single mode optical fibre and cable for the access network. ITU-T G.783 Recommendation ITU-T G.783 (2006, as amended), Characteristics of synchronous digital hierarchy (SDH) equipment functional blocks. ITU-T G.825 Recommendation ITU-T G.825 (2000, as amended
37、), The control of jitter and wander within digital 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
38、.1 (2016), Optical transport network physical 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. 2 Rec. ITU-T G.987.2 (2016)/Amd.1 (08/2017) ITU-T G.984.1 Recommendation ITU-T G.984.1 (2008
39、, as amended), Gigabit-capable passive optical networks (GPON): General characteristics. ITU-T G.984.2 Recommendation ITU-T G.984.2 (2003, as amended), Gigabit-capable Passive Optical Networks (G-PON): Physical Media Dependent (PMD) layer specification. ITU-T G.984.5 Recommendation ITU-T G.984.5 (20
40、14), Gigabit-capable Passive Optical Networks (G-PON): Enhancement band. ITU-T G.987 Recommendation ITU-T G.987 (2012), 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-capable passive
41、optical network (XG-PON): General requirements. ITU-T G.987.3 Recommendation ITU-T G.987.3 (2014), 10-Gigabit-capable passive optical networks (XG-PON): Transmission convergence (TC) layer specification. ITU-T G.988 Recommendation ITU-T G.988 (2012), ONU management and control interface (OMCI) speci
42、fication. ITU-T G-Sup.39 ITU-T G-series Recommendations Supplement 39 (2016), Optical system design and engineering considerations. ITU-T L.313 Recommendation ITU-T L.313/L.66 (2007), Optical fibre cable maintenance criteria for in-service fibre testing in access networks. 3 Definitions See clause 3
43、 of ITU-T G.987. 4 Abbreviations and acronyms See clause 4 of ITU-T G.987. 5 Conventions See clause 5 of ITU-T G.987. 6 Architecture of the optical access network See ITU-T G.984.1. For convenience, Figure 1 of ITU-T G.984.2 is reproduced below. Rec. ITU-T G.987.2 (2016)/Amd.1 (08/2017) 3 Figure 6-1
44、 Generic physical configuration of the optical distribution network (reproduced from Figure 1 of ITU-T G.984.2) The following reference points are defined in Figure 6-1: S: Point on the optical fibre just after the OLTDownstream/ONUUpstream optical connection point (i.e., optical connector or optica
45、l splice). R: Point on the optical fibre just before the ONUDownstream/OLTUpstream optical connection point (i.e., optical connector or optical splice). S/R, R/S: Combination of points S and R existing simultaneously in a single fibre, when operating in bidirectional mode. Oru, Ord: Optical interfac
46、e at the reference point R/S between the ONU and the ODN for the upstream and downstream directions respectively. Olu, Old: Optical interfaces at the reference point S/R between the OLT and the ODN for the upstream and downstream directions respectively. The two directions for optical transmission i
47、n the ODN are identified as follows: downstream direction for signals travelling from the OLT to the ONU(s), and upstream direction for signals travelling from the ONU(s) to the OLT. Transmission in downstream and upstream directions takes place on the same fibre and components (duplex/diplex config
48、uration). 6.1 Classes for optical path loss Recommended classes for optical path loss are shown in Table 6-1. Table 6-1 Classes for optical path loss defined in this Recommendation Nominal1 class (N1 class) Nominal2 class (N2 class) Extended1 class (E1 class) Extended2 class (E2 class) Minimum loss
49、14 dB 16 dB 18 dB 20 dB Maximum loss 29 dB 31 dB 33 dB 35 dB 4 Rec. ITU-T G.987.2 (2016)/Amd.1 (08/2017) For single-star architectures, the absence of optical branching devices may result in optical path losses of less than 5 dB. In such a case, the ODN must contain additional optical attenuators guaranteeing minimum channel insertion loss for the given class to prevent potential damage to receivers. 6.2 Categories for fibre differential distance Categories
