1、 International Telecommunication Union ITU-T G.992.3TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Corrigendum 1(11/2009) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Access networks Asymmetric digital subscriber line transceivers 2
2、 (ADSL2) Corrigendum 1 Recommendation ITU-T G.992.3 (2009) Corrigendum 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 TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS
3、 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 COORDINATION OF RADIOTELEPHONY AND LI
4、NE 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.910G.919 Digital sections a
5、t 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 and digital transmission sys
6、tems 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.999MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTE
7、RISTICS 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.992.3 (2009)/Cor.1 (11/2009) i Recommendation ITU-T G.992.3 Asymmetric di
8、gital subscriber line transceivers 2 (ADSL2) Corrigendum 1 Summary Corrigendum 1 to Recommendation ITU-T G.992.3 (2009) contains: Corrections to test parameters definitions and accuracy. Editorial change to clause on interleaver. History Edition Recommendation Approval Study Group 1.0 ITU-T G.992.3
9、2002-07-29 15 1.1 ITU-T G.992.3 (2002) Amend. 1 2003-05-22 15 1.2 ITU-T G.992.3 (2002) Cor. 1 2003-12-14 15 1.3 ITU-T G.992.3 (2002) Cor. 2 2004-02-22 15 1.4 ITU-T G.992.3 (2002) Amend. 2 2004-04-30 15 1.5 ITU-T G.992.3 (2002) Amend. 3 2004-06-13 15 1.6 ITU-T G.992.3 (2002) Amend. 4 2004-06-13 15 2.
10、0 ITU-T G.992.3 2005-01-13 15 2.1 ITU-T G.992.3 (2005) Amend. 1 2005-09-22 15 2.2 ITU-T G.992.3 (2005) Amend. 2 2006-03-29 15 2.3 ITU-T G.992.3 (2005) Amend. 3 2006-12-14 15 2.4 ITU-T G.992.3 (2005) Amend. 4 2007-07-29 15 2.5 ITU-T G.992.3 (2005) Amend. 5 2008-06-22 15 3.0 ITU-T G.992.3 2009-04-22 1
11、5 3.1 ITU-T G.992.3 (2009) Cor. 1 2009-11-13 15 3.2 ITU-T G.992.3 (2009) Amend. 1 2010-03-01 15 ii Rec. ITU-T G.992.3 (2009)/Cor.1 (11/2009) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communica
12、tion 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 Wo
13、rld 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. I
14、n 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 for conciseness to indicate both a telecommunication administration and a reco
15、gnized 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 w
16、ords “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 th
17、at 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 Rights, whether asserted by ITU members or others outside of the Recommenda
18、tion development process. As of the date of approval of this Recommendation, ITU had 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
19、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.992.3 (2009)/Cor.1 (11/2009) 1 Recommendation I
20、TU-T G.992.3 Asymmetric digital subscriber line transceivers 2 (ADSL2) Corrigendum 1 1) Test parameters definitions and accuracy a) Change the text of clause 8.12.3.4 as follows: 8.12.3.4 Loop attenuation (LATN) The loop attenuation (LATN) is the difference in dB between the power received at the ne
21、ar-end and that transmitted from the far-end over all subcarriers, i.e., the squared magnitude of the channel characteristics function H(f) (as defined in 8.12.3.1) averaged over all subcarriers and this average converted to dB. LATN shall be defined as: NSCfiHdBLATNNSCi=102)(log10 with NSC the numb
22、er of subcarriers (see 8.5) and H(f) represented by Hlin(f) in diagnostics mode and Hlog(f) in initialization (with conversion of log to linear values for use in the above equation). b) Change the text of clause 8.12.5.3 as follows, and renumber the equations of clause 8 accordingly: 8.12.5.3 Signal
23、 to noise ratio per subcarrier (SNRps) For each downstream subcarrier where the SNRps_ds accuracy requirement applies, the statistical sample variance of SNRps_ds measurements (expressed in dB, and all samples taken over a 10-minute time interval, without line re-initialization in this time interval
24、, and under the same loop, noise, temperature, and configuration settings) shall be equal to or smaller than 0.5dB, as calculated with equations (8-1). 5.0var_ ianceSNRps where ()=NiavgSNRpsiSNRpsNianceSNRps12_)(1var_ (8-1) =NiiSNRpsNavgSNRps1)(1_ 2 Rec. ITU-T G.992.3 (2009)/Cor.1 (11/2009) For each
25、 upstream subcarrier where the SNRps_us accuracy requirement applies, the statistical sample variance of SNRps_us measurements (expressed in dB, and all samples taken over a 10-minute time interval, without line re-initialization in this time interval, and under the same loop, noise, temperature, an
26、d configuration settings) shall be equal to or smaller than 0.5dB, as calculated with equations (8-1). 2) Editorial correction to clause on interleaver Make the following editorial corrections in clause 7.7.1.5 With Dp one of the mandatory values identified in Table 7-9, Table 7-10, Table 7-11 or Ta
27、ble 7-121, and with the above-defined rule, the output octets from the interleaver always occupy distinct time slots when NFEC.p is odd and Dp is a power of 2. When NFEC.p is even, a dummy octet shall be added at the beginning of the codeword at the input to the interleaver. The resultant odd-length
28、 codeword is then convolutionally interleaved, and the dummy octet shall then be removed from the output of the interleaver. With D0 one of the optional (i.e., valid as identified in Table 7-8, but not mandatory as identified in Table 7-9, Table 7-10, Table 7-11 or Table 7-12) values identified in T
29、able 7-8, the codeword length NFEC.0 and D0 shall be co-prime (i.e., have no common divisors except for 1). No dummy octets shall be used, as with the above-defined rule, the output octets from the interleaver always occupy distinct time slots. Printed in Switzerland Geneva, 2010 SERIES OF ITU-T REC
30、OMMENDATIONS 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, digital systems and network
31、s 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 protection of cables and ot
32、her 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 Terminals and subjective and objective assessmen
33、t methods 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
