1、 International Telecommunication Union ITU-T G.986TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2010) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Optical line systems for local and access networks 1 Gbit/s point-to-point Ether
2、net-based optical access system Recommendation ITU-T G.986 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.200G.299 IN
3、DIVIDUAL 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 TELEPHONY G
4、.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 Parameters for optical fibre cable systems G.910G.919 Digital sections at hierarchical
5、 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 line systems G.950G.959 Digital section and digital transmission systems for custo
6、mer access to ISDN G.960G.969 Optical fibre submarine cable systems G.970G.979 Optical line systems for local and access networks G.980G.989Access networks G.990G.999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000
7、G.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.986 (01/2010) i Recommendation ITU-T G.986 1 Gbit/s point-to-point Ethernet-based optic
8、al access system Summary Recommendation ITU-T G.986 describes a 1 Gbit/s point-to-point Ethernet-based optical access system for the optical access services including the optical distribution network (ODN) specification, the physical layer specification and the operation, administration and maintena
9、nce (OAM) specification. History Edition Recommendation Approval Study Group 1.0 ITU-T G.986 2010-01-13 15 ii Rec. ITU-T G.986 (01/2010) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication
10、 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 questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World
11、Telecommunication Standardization 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 so
12、me 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 Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recogniz
13、ed operating agency. Compliance with 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
14、 “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 compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that t
15、he 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 applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation
16、 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 implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are
17、therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2010 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.986 (01/2010) iii CONTENTS Page 1 Scope 1 2 Ref
18、erences. 1 3 Definitions 1 3.1 Terms defined elsewhere 1 4 Abbreviations 2 5 Configuration of an OAN . 2 5.1 System configuration 2 5.2 Fibre type 2 5.3 Transmission methodology 3 5.4 Wavelength allocation 3 5.5 ODN model 3 5.6 Classes for optical path loss . 3 5.7 Reflectance in ODN . 3 6 Physical
19、layer specification 3 6.1 Transmit wavelength/Receive wavelength . 5 6.2 Bit rate and line coding . 5 6.3 Spectral characteristics . 5 6.4 Mean launched power . 6 6.5 Receiver characteristics 6 6.6 Extinction ratio . 6 6.7 Pulse mask 6 6.8 S/X 6 6.9 Optical return loss of the interface . 6 6.10 Test
20、 pattern . 6 6.11 Signal detect . 6 7 OAM specification for single domain ONT management 6 7.1 OAM structure 6 7.2 OMCI Ethernet frame . 7 7.3 Activation process 9 7.4 ONT with multiple UNI ports 10 7.5 Managed entities . 11 7.6 Managed entity relation diagram 11 7.7 MIB description 11 8 OAM specifi
21、cation for two-domain ONT management . 11 9 Other requirements . 11 9.1 Silent start function of ONT . 11 Rec. ITU-T G.986 (01/2010) 1 Recommendation ITU-T G.986 1 Gbit/s point-to-point Ethernet-based optical access system 1 Scope This Recommendation describes a 1 Gbit/s point-to-point Ethernet-base
22、d optical access system for the optical access services including the optical distribution network (ODN) specification, the physical layer specification and the operation, administration and maintenance (OAM) specification. For an effective use of optical fibres cited in ITU-T G.985, this Recommenda
23、tion specifies only a single fibre bidirectional transmission system, dual-fibre systems being out of the scope of this Recommendation. This Recommendation describes the case of a single domain managed ONT and related OLT requirements. The case of a dual domain managed ONT and related OLT requiremen
24、ts are for future study. 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 Recommendations and other referenc
25、es 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 published. The reference to
26、a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.984.4 Recommendation ITU-T G.984.4 (2008), Gigabit-capable passive optical networks (G-PON): ONT management and control interface specification. ITU-T G.985 Recommendation ITU-T
27、 G.985 (2003), 100 Mbit/s point-to-point Ethernet based optical access system. IEEE 802 IEEE Standard 802-2001, Local and Metropolitan Area Networks: Overview and Architecture. IEEE 802.3 IEEE Standard 802.3-2008, Information technology Local and metropolitan area networks Part 3: Carrier Sense Mult
28、iple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 optical access network (OAN) ITU-T G.985: The set of access links sharing the same network-s
29、ide interfaces and supported by optical access transmission systems. 3.1.2 optical distribution network (ODN) ITU-T G.985: An ODN provides the optical transmission means from the OLT towards the users, and vice versa. It utilizes passive optical components. 3.1.3 optical line termination (OLT) ITU-T
30、 G.985: An OLT provides the network-side interface of the OAN, and is connected to the ODN. 2 Rec. ITU-T G.986 (01/2010) 3.1.4 optical network termination (ONT) ITU-T G.985: An ONT provides the user-side interface of the OAN, and is connected to the ODN. 3.1.5 wavelength division multiplexing (WDM)
31、ITU-T G.985: Bidirectional multiplexing using different optical wavelength for up and downstream signals. 4 Abbreviations This Recommendation uses the following abbreviations: ANI Access Node Interface GEM G-PON Encapsulation Method GMII Gigabit Media Independent Interface MAC Media Access Control M
32、IB Management Information Base MLM Multi-Longitudinal Mode OAM Operation, Administration and Maintenance OAN Optical Access Network ODN Optical Distribution Network OLT Optical Line Termination OMCC ONT Management and Control Channel OMCI ONT Management and Control Interface ONT Optical Network Term
33、ination OUI Organizationally Unique Identifier PCS Physical Coding Sub-layer PMA Physical Medium Attachment PMD Physical Medium Dependent RMS Root Mean Square RS Reconciliation Sub-layer SLM Single Longitudinal Mode UNI User Network Interface WDM Wavelength Division Multiplexing 5 Configuration of a
34、n OAN 5.1 System configuration See clause 5.1 of ITU-T G.985. 5.2 Fibre type See clause 5.2 of ITU-T G.985. Rec. ITU-T G.986 (01/2010) 3 5.3 Transmission methodology Bidirectional transmission is accomplished by use of the wavelength division multiplexing (WDM) technique of the 1310 nm band (1260-13
35、60 nm) and the 1490 nm band (1480-1500 nm) wavelengths on a single fibre, allowing the connection to be a point-to-point type ODN. 5.4 Wavelength allocation For downstream, the operating wavelength range should be 1480-1500 nm. For upstream, the operating wavelength range should be 1260-1360 nm. The
36、se wavelength ranges are compatible with 1000BASE-BX10 specified in clause 59 of IEEE 802.3. 5.5 ODN model See clause 5.5 of ITU-T G.985. 5.6 Classes for optical path loss Recommended classes for optical path loss are shown in Table 1. Table 1 Classes for optical path loss Class S Class A Class B Mi
37、nimum loss 0 dB 4 dB 12 dB Maximum loss 15 dB 20 dB 25 dB 5.7 Reflectance in ODN See clause 5.7 of ITU-T G.985. 6 Physical layer specification The optical interface of optical network termination (ONT) and optical line termination (OLT) should follow the transmission and coding specification in conf
38、ormance with physical medium attachment (PMA), physical coding sub-layer (PCS), gigabit media-independent interface (GMII), reconciliation sub-layer (RS) for 1000BASE-X. PMA and PCS are defined in clause 36 of IEEE 802.3. GMII and RS are defined in clause 35 of IEEE 802.3. This physical layer specif
39、ication should have functionalities based on the physical medium dependent (PMD) sublayer defined in clause 59 of IEEE 802.3. The operation of the optical interface shall be full-duplex. Physical layer specification is also specified for each of the following applicable areas: Class S: optical path
40、loss 15 dB, power penalty 1 dB for transmission within 10 km. Class A: optical path loss 20 dB, power penalty 1 dB for transmission within 20 km. Class B: optical path loss 25 dB, power penalty 1 dB for transmission within 30 km. NOTE The distance described above is not a standard, but for classific
41、ation. All parameters are specified as follows, and should be in accordance with Table 2 for an ONT, and Table 3 for an OLT. Transmit wavelength, receive wavelength, line code, maximum RMS width for MLM laser, pulse mask and bit error ratio specified in Tables 2 and 3 are compatible with 1000BASE-BX
42、10 specified in clause 59 of IEEE 802.3. Either the damage threshold included in Tables 2 and 3 shall be met, or, the receiver shall be labelled to indicate the maximum optical input power level to which it can be continuously exposed without damage. 4 Rec. ITU-T G.986 (01/2010) Table 2 Physical lay
43、er specification for ONT Items Unit Specification ODN class Class S Class A Class B Nominal bit rate Gbit/s 1.25 Transmit wavelength nm 1260-1360 Receive wavelength nm 1480-1500 Line code 8B10B block coding Spectral characteristic If MLM laser Maximum RMS width nm See Table 59-4 of IEEE 802.3 (Note)
44、 (Note) (Note) If SLM laser Maximum 20 dB width nm Less than 1 (Note) If SLM laser Minimum side mode suppression ratio dB More than 30 (Note) Mean launch power MAX dBm 0 +4 +4 Mean launch power MIN dBm 6 3 3 Minimum overload dBm 0 0 8 Minimum sensitivity dBm 22 24 29 Damage threshold MAX dBm +4 7 Po
45、wer penalty dB 1 Extinction ratio dB More than 8.2 Pulse mask X1,X2,Y1,Y2,Y3 UI 0.22,0.375,0.2,0.2,0.3 See Figure 59-4 of IEEE 802.3 S/X Optical return loss condition dB More than 14 Bit error ratio Less than 1012Optical return loss of the interface dB More than 14 NOTE Either MLM laser or SLM laser
46、 will be selected for Class S. Only SLM laser will be selected for Class A and Class B. Rec. ITU-T G.986 (01/2010) 5 Table 3 Physical layer specification for OLT Items Unit Specification ODN class Class S Class A Class B Nominal bit rate Gbit/s 1.25 Transmit wavelength nm 1480-1500 Receive wavelengt
47、h nm 1260-1360 Line code 8B10B block coding Spectral characteristic If MLM laser Maximum RMS width nm (Note) (Note) (Note) If SLM laser Maximum 20 dB width nm Less than 1 (Note) If SLM laser Minimum side mode suppression ratio dB More than 30 (Note) Mean launch power MAX dBm 0 +4 +4 Mean launch powe
48、r MIN dBm 6 3 3 Minimum overload dBm 0 0 8 Minimum sensitivity dBm 22 24 29 Damage threshold MAX dBm +4 7 Power penalty dB 1 Extinction ratio dB More than 8.2 Pulse mask X1,X2,Y1,Y2,Y3 UI 0.22,0.375,0.2,0.2,0.3 See Figure 59-4 of IEEE 802.3 S/X Optical return loss condition dB More than 14 Bit error
49、 ratio Less than 1012Optical return loss of the interface dB More than 14 NOTE Only SLM laser will be selected for Class S, Class A and Class B. 6.1 Transmit wavelength/Receive wavelength The transmit and receive wavelengths are described in clauses 5.3 and 5.4. 6.2 Bit rate and line coding Bit rate of both upstream and downstream is 1.25 Gbit/s, but its effective bandwidth is 1 Gbit/s because the line coding
