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.984.5 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (05/2014) 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 Gigabit-capable passive optical networks (GPON): Enhancement band Recommendation ITU-T G.984.5 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
3、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 WITH METALLIC LINES G.400G.449 COORDINAT
4、ION 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 Parameters for optical fibre cable systems G
5、.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 line systems G.950G.959 Digital section
6、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 PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.
7、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-T G.984.5 (05/2014) i Recommendation IT
8、U-T G.984.5 Gigabit-capable passive optical networks (GPON): Enhancement band Summary Recommendation ITU-T G.984.5 defines wavelength ranges reserved for additional service signals to be overlaid via wavelength division multiplexing (WDM) in future passive optical networks (PON) for maximizing the v
9、alue of optical distribution networks (ODNs). History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G.984.5 2007-09-22 15 11.1002/1000/9185 1.1 ITU-T G.984.5 (2007) Amd.1 2009-10-09 15 11.1002/1000/10543 2.0 ITU-T G.984.5 2014-05-14 15 11.1002/1000/12184 _ * To access the Recommen
10、dation, 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.984.5 (05/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations spec
11、ialized 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 questions and issuing Recommendations on them
12、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 Recommendations on these topics. The approval of ITU-T R
13、ecommendations 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 Recommendation, the expression “Administration“ is used fo
14、r 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 or applicability) and compliance with the Rec
15、ommendation 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 compliance with the Recommendation is required of any
16、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 applicability of claimed Intellectual Property
17、 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 implement this Recommendation. However, implem
18、enters 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 2014 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written
19、 permission of ITU. Rec. ITU-T G.984.5 (05/2014) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 3 6 Reference architecture 3 7 Operating wavelength . 6 8 X
20、/S tolerance of G-PON ONU . 8 Appendix I Example of WDM1, WDM1r, CEx and CEMx characteristics . 10 Appendix II Examples of wavelength allocation for NGA services and video distribution services 23 II.1 Introduction 23 II.2 Case 1: Integrated filter for video . 23 Appendix III Methods for calculating
21、 required isolation for WDM/CE/CEM devices 27 Rec. ITU-T G.984.5 (05/2014) 1 Recommendation ITU-T G.984.5 Gigabit-capable passive optical networks (GPON): Enhancement band 1 Scope The purpose of this Recommendation is to define wavelength ranges reserved for additional service signals to be overlaid
22、 via wavelength division multiplexing (WDM) in future gigabit-capable passive optical networks (G-PON) for maximizing the value of optical distribution networks (ODNs). Other PON systems, such as B-PON, have wavelength plans based on ITU-T G.983.3, which includes existing options for enhancement ban
23、ds. This Recommendation also defines further wavelength ranges reserved for additional service signals to be overlaid via WDM in future PONs whose wavelength allocations are based on ITU-T G.983.3. For this purpose, this Recommendation defines and provides: wavelength ranges to be reserved; and X/S
24、tolerance in PON optical network units (ONUs). Appendices I, II and III provide: sample parameters of a discrete WDM filter that combines and isolates the G-PON up/down signals and enhancement bands at the OLT side; examples of wavelength allocation for NGA services and video distribution services;
25、methods for calculating required isolation for WDM/CE/CEM devices. The physical media dependent (PMD) layer specification for G-PON in the absence of an enhancement band is defined in ITU-T G.984.2. PMD layer specifications for G-PON in the presence of enhancement bands are defined by the combinatio
26、n of ITU-T G.984.2 and this Recommendation. Whenever a parameter specified in ITU-T G.984.2 is not explicitly mentioned in this Recommendation, its value given in ITU-T G.984.2 remains valid. Whenever a parameter is specified in both this Recommendation and ITU-T G.984.2, the specification in this R
27、ecommendation takes precedence. 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 r
28、eferences 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 refere
29、nce 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.671 Recommendation ITU-T G.671 (2012), Transmission characteristi
30、cs of optical components and subsystems. 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.983.3 Recommendation ITU-T G.983.3 (2001), A broadband optical access system with increased service capability by wavelength a
31、llocation. 2 Rec. ITU-T G.984.5 (05/2014) 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.987 Recommendation ITU-T G.987 (2012), 10-Gigabit-capable passive optical network (XG-PON) system
32、s: Definitions, abbreviations and acronyms. 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.989 Recommendation ITU-T G.989 (2014), 40-Gigabit-capable passive optical network (NG-PON2)
33、 systems: Definitions, abbreviations 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 L.66 Recommendation ITU-T L.66 (2007), Optical fibre cable maintenance criteria for in-service fibre testing in acc
34、ess networks. 3 Definitions This Recommendation makes frequent use of the terms defined in ITU-T G.983.1, ITU-T G.983.3 and ITU-T G.984.2. For purposes of convenience, the main definitions related to the G-PON enhancement bands are reported in this clause. 3.1 Terms defined elsewhere This Recommenda
35、tion uses the following terms defined elsewhere: 3.1.1 optical distribution network (ODN): ITU-T G.984.2. 3.1.2 optical line termination (OLT): ITU-T G.984.2. 3.1.3 optical network unit (ONU): ITU-T G.984.2. 3.1.4 wavelength division multiplexing (WDM): ITU-T G.984.2. 3.1.5 10-Gigabit-capable passiv
36、e optical network (XG-PON): ITU-T G.987. 3.1.6 TWDM PON: ITU-T G.989. 3.1.7 PtP WDM PON: ITU-T G.989. 3.1.8 NG-PON2: ITU-T G.989. 3.1.9 coexistence element (CE): ITU-T G.989. 3.1.10 wavelength multiplexer (WM): ITU-T G.989. 3.2 Terms defined in this Recommendation This Recommendation defines the fol
37、lowing terms: 3.2.1 next generation access (NGA): A possible new optical access system that coexists with G-PON on the same ODN. 3.2.2 wavelength blocking filter (WBF): An optical filter to prevent an optical receiver from receiving unwanted optical signals with different wavelengths. 4 Abbreviation
38、s and acronyms This Recommendation uses the following abbreviations and acronyms: B-PON Broadband Passive Optical Network CE Coexistence Element Rec. ITU-T G.984.5 (05/2014) 3 CEM Coexistence Element/Multiplexer CNR Carrier-to-Noise Ratio DBA Determined By Application DFB Distributed Feedback Laser
39、G-PON Gigabit-capable Passive Optical Network NRZ Non Return to Zero NG-PON2 Next Generation Passive Optical Network phase 2 NGA Next Generation Access OAN Optical Access Network ODN Optical Distribution Network OLT Optical Line Termination ONU Optical Network Unit OTDR Optical Time Domain Reflectom
40、eter PMD Physical Media Dependent PON Passive Optical Network PtP WDM Point-to-Point Wavelength Division Multiplexing RF Radio Frequency TWDM Time and Wavelength Division Multiplexing WBF Wavelength Blocking Filter WDM Wavelength Division Multiplexing WM Wavelength Multiplexer XG-PON 10-Gigabit-capa
41、ble Passive Optical Network. 5 Conventions None. 6 Reference architecture Figure 1 (reproduced for convenience from Figure 5 of ITU-T G.983.1) shows the generic physical configuration of an optical access network. 4 Rec. ITU-T G.984.5 (05/2014) G .9 8 4 .2 _ F 0 1O L TR / S S/ ROrd, OruODNR / SONUnO
42、NU1Old, OluR e f e r e nc e p oi nt sO pt i c a l i n t e r f a c e sR e pr e s e nt o ne o r m or e f i br eR e pr e s e nt o pt i o na l pr ot e c t i on f i br e sOrd, OruOrd, Oru, Old, OluR a n d SFigure 1 Generic physical configuration of the optical access network (Reproduced from Figure 5 of
43、ITU-T G.983.1) The two directions for optical transmission in the ODN are identified as follows: downstream direction for signals travelling from the OLT to the ONU(s); upstream direction for signals travelling from the ONU(s) to the OLT. According to ITU-T G.983.1, transmission in downstream and up
44、stream directions can take place on the same fibre and components (duplex/diplex working) or on separate fibres and components (simplex working). This Recommendation covers only diplex working, i.e., bidirectional transmission using different wavelengths over a single fibre. There can be several typ
45、es of ODN architectures to achieve the coexistence of G-PON and additional services including next generation access (NGA) and video distribution services. Figures 2 and 3 are reference diagrams of optical access network (OAN) architectures and assume that wavelength blocking filters (WBF) are used
46、when G-PON, video and NGA share the same ODN. Note that these reference diagrams only provide reference configurations of the ODN and WBF and are not intended to limit future designs and implementations. Rec. ITU-T G.984.5 (05/2014) 5 (NOTE WDM1 can be replaced by WDM1r, CE or CEM.) Figure 2 Optical
47、 access network architecture reference diagram 1 Figure 3 Optical access network architecture reference diagram 2 The following abbreviations are used in Figures 2 and 3: CE Coexistence element that may be located in the central office to combine/isolate the wavelengths of NG-PON2 and legacy PON sig
48、nals and which occasionally combines the video signals and/or OTDR signals CEM Coexistence element that may be located in the central office to combine/isolate the wavelengths of TWDM PON, PtP WDM PON and legacy PON signals and which occasionally combines the video signals and/or OTDR signals Rx Opt
49、ical receiver Tx Optical transmitter V-Rx Video receiver 6 Rec. ITU-T G.984.5 (05/2014) V-Tx Video transmitter WBF Wavelength blocking filter for blocking interference signals to Rx WBF-V Wavelength blocking filter for blocking interference signals to V-Rx WDM-N WDM filter in G-PON ONU to combine/isolate the wavelengths of G-PON upstream and downstream WDM-N WDM filter in G-PON ONU to combine/isolate the wavelengths of G-PON
