1、 International Telecommunication Union ITU-T G.984.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1(10/2009) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Optical line systems for local and access networks Gigabit-capable
2、passive optical networks (GPON): General characteristics Amendment 1 Recommendation ITU-T G.984.1 (2008) Amendment 1 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON
3、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 WITH METALLIC LINES G.40
4、0G.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 Parameters for optical fibre
5、 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 line systems G.950G.959
6、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.989Access networks G.990G.999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPE
7、CTS 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-T G.984.1 (2008)/Amd.1 (10/2009)
8、i Recommendation ITU-T G.984.1 Gigabit-capable passive optical networks (GPON): General characteristics Amendment 1 Source Amendment 1 to Recommendation ITU-T G.984.1 (2008) was agreed on 9 October 2009 by ITU-T Study Group 15 (2009-2012). ii Rec. ITU-T G.984.1 (2008)/Amd.1 (10/2009) FOREWORD The In
9、ternational 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 studying technical,
10、 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 groups which, in tu
11、rn, 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 ISO and IEC. NOT
12、E 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 provisions (to ensure e
13、.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 words does not
14、suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU 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
15、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 not received notice of intellectual property, protected by patents, whi
16、ch 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 2010 All rights reserved. No part of this publication m
17、ay be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.984.1 (2008)/Amd.1 (10/2009) 1 Recommendation ITU-T G.984.1 Gigabit-capable passive optical networks (GPON): General characteristics Amendment 1 1) Clause I.3.1, Common functions a) Modify the text i
18、mmediately following Figure I.8 to read: “The GPON real-time management clock service is shown in Figure I.9. The OLT receives real-time clock data (typically using NTP, over an Ethernet interface via UDP over IP). The OLT thereby maintains its own internal RTC, which it uses to timestamp all manner
19、 of event data. Other methods of establishing the OLT RTC are possible, see Figure I.10a. The ONT does not extend this RTC for the purposes of management. Rather, its performance-monitoring and event-collection processes are synchronized with those of the OLT via the OMCI. The OLT routinely collects
20、 all of this data every 15 minutes and logs it with the OLT RTC.“ b) Change the title of Figure I.9 to read: “Figure I.9 Real-time management clock service“ c) Insert the following text and figure immediately after Figure I.10: For applications where the ONT requires a very accurate real-time clock
21、with phase errors in the nanoseconds range, the following precision real-time clock is defined. The OLT obtains a precise real-time clock, typically using IEEE 1588, optionally with some additional assistance of the previously mentioned network clock service. The OLT then passes this clocking inform
22、ation to the ONTs using a combination of the TC layer and the OMCI layer. The TC-layer provides a very accurate local time using the G-PON superframe counter. The OMCI-layer communicates the offset between the local time and the global time from the OLT to the ONT. The ONT can then calculate the pre
23、cise time, and establish its precision RTC. If the ONT must pass the precision RTC on to client equipment, it can support the IEEE 1588 protocol towards the UNI side. Figure I.10a Precision real-time clock service Printed in Switzerland Geneva, 2010 SERIES OF ITU-T RECOMMENDATIONS Series A Organizat
24、ion of the work of ITU-T Series D General tariff principles Series E Overall network operation, telephone service, service operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and media, digital systems and networks Series H Audiovisual and mult
25、imedia systems Series I Integrated services digital network Series J Cable networks and transmission of television, sound programme and other multimedia signals Series K Protection against interference Series L Construction, installation and protection of cables and other elements of outside plant S
26、eries M Telecommunication management, including TMN and network maintenance Series N Maintenance: international sound programme and television transmission circuits Series O Specifications of measuring equipment Series P Terminals and subjective and objective assessment methods Series Q Switching an
27、d signalling Series R Telegraph transmission Series S Telegraph services terminal equipment Series T Terminals for telematic services Series U Telegraph switching Series V Data communication over the telephone network Series X Data networks, open system communications and security Series Y Global information infrastructure, Internet protocol aspects and next-generation networks Series Z Languages and general software aspects for telecommunication systems
