1、 International Telecommunication Union ITU-T G.985TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1(01/2009) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Optical line systems for local and access networks 100 Mbit/s point-t
2、o-point Ethernet based optical access system Amendment 1: Silent start function of optical network terminals Recommendation ITU-T G.985 (2003) Amendment 1 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.10
3、0G.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-RELAY OR SATELLITE LINKS AND IN
4、TERCONNECTION 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 SYSTEM G.900G.999 General G
5、.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 FDM transmission bearers G.940
6、G.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 Access networks G.990G.999 QUALITY OF SERVICE AND PERFORMANCE G
7、ENERIC 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.8999ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.98
8、5 (2003)/Amd.1 (01/2009) i Recommendation ITU-T G.985 100 Mbit/s point-to-point Ethernet based optical access system Amendment 1 Silent start function of optical network terminals Summary Amendment 1 to Recommendation ITU-T G.985 contains modifications to the text of Recommendation ITU-T G.985 (2003
9、) to add a silent start function for optical network terminals (ONT). Source Amendment 1 to Recommendation ITU-T G.985 (2003) was approved on 13 January 2009 by ITU-T Study Group 15 (2009-2012) under Recommendation ITU-T A.8 procedure. ii Rec. ITU-T G.985 (2003)/Amd.1 (01/2009) FOREWORD The Internat
10、ional 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, opera
11、ting 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 turn, pr
12、oduce 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. NOTE In t
13、his 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.g. in
14、teroperability 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
15、 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 evidenc
16、e, 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, which may
17、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 2009 All rights reserved. No part of this publication may be r
18、eproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.985 (2003)/Amd.1 (01/2009) 1 Recommendation ITU-T G.985 100 Mbit/s point-to-point Ethernet based optical access system Amendment 1 Silent start function of optical network terminals 1 Update of Reference 5
19、in clause 2 Update Reference 5 in clause 2 as follows. 5 IEEE Standard 802.3-2005, Information technology LAN/MAN Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications. 2 Clarification of relationship to Reference 5 in clause 5 Add t
20、he following text at the end of clause 5.4 (Wavelength allocation). “These wavelength ranges are compatible with 100BASE-BX10 specified in IEEE Standard 802.3 clause 58 5.“ 3 Clarification of relationship to Reference 5 in clause 6 Change “100 BASE-FX (IEEE Standard 802.3)“ into “100BASE-BX10 (IEEE
21、Standard 802.3)“ in clause 6. 4 Addition of clauses 8 and 8.1 Add a new clause clause 8 “Other requirements“ and a new clause 8.1 “Silent start function of ONT“ with the following text: 8 Other requirements 8.1 Silent start function of ONT The transmitter in the ONT must be initially disabled so as
22、to avoid disturbing other access systems in case of mis-connection. ONT shall enable the transmitter to enter a handshaking process with OLT only after confirming that the frame structure and/or the line coding of the received downstream signal are consistent with those of the relevant standard to w
23、hich the ONT complies. When the connection between ONT and OLT is disabled, ONT shall return to the initial state in which the transmitter is disabled after waiting enough time from detecting the disconnection, so that ONT could send an alarm indication signal of the received signal managed entity t
24、o OLT. This is a unique function for the optical-access application that has directionality (i.e., it has different parameter values for upstream and downstream). In this regard, the relevant PMD type to implement this function in 5 is 100BASE-BX10 (clause 58 of 5). Printed in Switzerland Geneva, 20
25、09 SERIES OF ITU-T RECOMMENDATIONS Series A Organization 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, digit
26、al systems and networks Series H Audiovisual and multimedia 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 prote
27、ction of cables and other elements of outside plant Series 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 Telephone transmission qua
28、lity, telephone installations, local line networks Series Q Switching and 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
