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 (02/2016) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Optical line systems for local and access net
2、works 10-Gigabit-capable passive optical networks (XG-PON): Physical media dependent (PMD) layer specification Recommendation ITU-T G.987.2 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL
3、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-RELAY OR SATELLITE LINKS AND INTERCONNECTION W
4、ITH 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 SYSTEM G.900G.999 General G.900G.909 Param
5、eters 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 FDM transmission bearers G.940G.949 Digital l
6、ine 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 MULTIMEDIA QUALITY OF SERVICE AND PERFORMA
7、NCE 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 the list of ITU-T Recommendations. Rec. ITU-
8、T G.987.2 (02/2016) i Recommendation ITU-T G.987.2 10-Gigabit-capable passive optical networks (XG-PON): Physical media dependent (PMD) layer specification Summary Recommendation ITU-T G.987.2 describes the physical layer requirements and specifications for the XG-PON physical media dependent (PMD)
9、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 are described in Recommendation ITU-T G.988. Recommendation ITU-T G.
10、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. This Recommendation currently defines one type of 10-Gigabit-capable pa
11、ssive 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, hereinafter referred to as XG-PON1. This Recommendation describes a system that represents an evolutionary development from the systems
12、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. History Edition Recommendation Approval Study Group Unique ID* 1.0
13、 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 Keywords 10-Gigabit-capable passive optical network, FTTx network, OLT, ONU, optic, o
14、ptical network terminal (ONT), passive optical network (PON), physical layer interfaces, physical layer requirements, physical layer specification, PMD, XG-PON1. * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendatio
15、ns unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T G.987.2 (02/2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Tele
16、communication Standardization Sector (ITU-T) is a 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
17、Assembly (WTSA), which meets every four years, establishes 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
18、 which fall within ITU-Ts purview, the necessary 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 wi
19、th this Recommendation is voluntary. However, the 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
20、 language such as “must“ and the negative equivalents 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 RIGHTSITU draws attention to the possibility that the practice or implementation of t
21、his Recommendation may involve the use of a claimed 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 da
22、te of approval of this Recommendation, ITU had not received 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 consul
23、t the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2016 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.987.2 (02/2016) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definit
24、ions 2 4 Abbreviations and acronyms 2 5 Conventions 2 6 Architecture of the optical access network . 2 6.1 Classes for optical path loss . 3 6.2 Categories for fibre differential distance 3 7 Services . 3 8 User network interface and service node interface . 3 9 Optical network requirements . 4 9.1
25、Layered structure of optical network 4 9.2 Physical media dependent layer requirements for the XG-PON 4 10 X/S tolerance of XG-PON ONU 16 10.1 Versatile WDM configuration 17 11 Upstream physical layer overhead 17 Appendix I Examples of wavelength allocation for XG-PON, G-PON and video distribution s
26、ervices 18 Appendix II Physical layer measurements required to support optical layer supervision 19 Appendix III Allocation of the physical layer overhead time . 20 Appendix IV Jitter budget specifications 23 IV.1 The concept of jitter budget 23 IV.2 Definition of test points 24 IV.3 Jitter budget s
27、pecification for XG-PON1 . 25 IV.4 Jitter measurements for compliance to budget . 25 Appendix V Measurement of burst mode acquisition time and burst mode eye opening at OLT . 27 Bibliography. 30 Rec. ITU-T G.987.2 (02/2016) 1 Recommendation ITU-T G.987.2 10-Gigabit-capable passive optical networks (
28、XG-PON): Physical media dependent (PMD) layer specification 1 Scope This Recommendation pertains to flexible access networks using optical fibre technology. The focus is primarily on a network supporting services with bandwidth requirements ranging from that of voice to data services running at up t
29、o 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 between the user-network interface and the service node interface. The
30、 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 based on a point-to-multipoint tree and branch option. 2 References The
31、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 this
32、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 Recommendation does
33、 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), Characteristics of a bending loss insensitive single mode optical fibre and
34、 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), The control of jitter and wander within digital networks which are
35、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 (2016), Optical transport network physical layer interfaces. ITU-T
36、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.984.1 Recommendation ITU-T G.984.1 (2008, as amended), Gigabit-capable passive optical networks (GPON): General characteristics. ITU-T G.984.2 Recommendat
37、ion ITU-T G.984.2 (2003, as amended), Gigabit-capable Passive Optical Networks (G-PON): Physical Media Dependent (PMD) layer specification. 2 Rec. ITU-T G.987.2 (02/2016) ITU-T G.984.5 Recommendation ITU-T G.984.5 (2014), Gigabit-capable Passive Optical Networks (G-PON): Enhancement band. ITU-T G.98
38、7 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 optical network (XG-PON): General requirements. ITU-T G.987.3 Recommendation ITU-T
39、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) specification. ITU-T G-Sup.39 ITU-T G-series Recommendations Supplement 39 (2016), Optic
40、al 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 of ITU-T G.987. 4 Abbreviations and acronyms See clause 4 of ITU-T G.987. 5 Conven
41、tions 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. Figure 6-1 Generic physical configuration of the optical distribution network (reproduced from Figure 1 of ITU-T G.984.2) Rec. ITU-T G.98
42、7.2 (02/2016) 3 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 optical splice). R: Point on the optical fibre just before the ONUDownstream/OLTUpstream optical conne
43、ction 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 interface at the reference point R/S between the ONU and the ODN for the upstream and downstream directi
44、ons 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 in the ODN are identified as follows: downstream direction for signals travelling from the OLT to
45、 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 configuration). 6.1 Classes for optical path loss Recommended classes for optical path loss are shown
46、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 14 dB 16 dB 18 dB 20 dB Maximum loss 29 dB 31 dB 33 dB 35 dB For single-star architectures, the
47、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 differentia
48、l distance Categories for fibre differential distance Recommended categories for fibre differential distance (DD) are shown in Table 6-2. Table 6-2 Categories for fibre differential distance defined in G.987.2 DD20 DD40 Maximum differential distance 20 km 40 km 7 Services See clause 7 of ITU-T G.987
49、.1. 8 User network interface and service node interface See Appendix I of ITU-T G.987.1. 4 Rec. ITU-T G.987.2 (02/2016) 9 Optical network requirements 9.1 Layered structure of optical network See clause 5.2.5 of ITU-T G.987.1. 9.2 Physical media dependent layer requirements for the XG-PON All parameters are specified as follows, and are in accordance with Table 9-2 through Table 9-4. There are two optical network unit (ONU) types, based on different ONU
