1、 International Telecommunication Union ITU-T G.992.3TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 5(10/2012) 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) Amendment 5: Accuracy of test parameters Recommendation ITU-T G.992.3 (2009) Amendment 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 CARRI
3、ER-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 COORDINATION O
4、F 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.910G
5、.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 and d
6、igital 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.999MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRAN
7、SMISSION 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.992.3 (2009)/Amd.5 (10/2012) i Recommendation ITU-
8、T G.992.3 Asymmetric digital subscriber line transceivers 2 (ADSL2) Amendment 5 Accuracy of test parameters Summary Amendment 5 to Recommendation ITU-T G.992.3 (2009) covers the following functionality (it also applies to Recommendation ITU-T G.992.5 by reference): accuracy of test parameters (addin
9、g more functionality). History Edition Recommendation Approval Study Group 1.0 ITU-T G.992.3 2002-07-29 15 1.1 ITU-T G.992.3 (2002) Amd. 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) Amd. 2 2004-04-30 15 1.5 ITU-T
10、 G.992.3 (2002) Amd. 3 2004-06-13 15 1.6 ITU-T G.992.3 (2002) Amd. 4 2004-06-13 15 2.0 ITU-T G.992.3 2005-01-13 15 2.1 ITU-T G.992.3 (2005) Amd. 1 2005-09-22 15 2.2 ITU-T G.992.3 (2005) Amd. 2 2006-03-29 15 2.3 ITU-T G.992.3 (2005) Amd. 3 2006-12-14 15 2.4 ITU-T G.992.3 (2005) Amd. 4 2007-07-29 15 2
11、.5 ITU-T G.992.3 (2005) Amd. 5 2008-06-22 15 3.0 ITU-T G.992.3 2009-04-22 15 3.1 ITU-T G.992.3 (2009) Cor. 1 2009-11-13 15 3.2 ITU-T G.992.3 (2009) Amd. 1 2010-03-01 15 3.3 ITU-T G.992.3 (2009) Amd. 2 2010-07-29 15 3.4 ITU-T G.992.3 (2009) Amd. 3 2010-11-29 15 3.5 ITU-T G.992.3 (2009) Cor. 2 2011-06
12、-22 15 3.6 ITU-T G.992.3 (2009) Amd. 4 2011-10-29 15 3.7 ITU-T G.992.3 (2009) Amd. 5 2012-10-29 15 ii Rec. ITU-T G.992.3 (2009)/Amd.5 (10/2012) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and commun
13、ication 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
14、 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 Recommendations is covered by the procedure laid down in WTSA Resolution 1
15、. 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 for conciseness to indicate both a telecommunication administration and a r
16、ecognized 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. T
17、he 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 party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibilit
18、y 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 Rights, whether asserted by ITU members or others outside of the Recomm
19、endation 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
20、are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2013 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)/Amd.5 (10/2012) 1 Recommendati
21、on ITU-T G.992.3 Asymmetric digital subscriber line transceivers 2 (ADSL2) Amendment 5 Accuracy of test parameters 1) Change to clause 8.12.3.5 Add the following paragraph to the beginning of clause 8.12.3.5. 8.12.3.5 Signal attenuation (SATN) This clause provides the requirements and definitions on
22、 signal attenuation (SATN). These definitions and requirements apply to both the downstream signal attenuation SATNds and upstream signal attenuation SATNus. The signal attenuation (SATN) is defined as the difference in dB between the power received at the near end and that transmitted from the far
23、end. 2) Changes to clauses 8.12.5.1.1 and 8.12.5.1.2 Introduce the changes shown below to clauses 8.12.5.1.1 and 8.12.5.1.2. 8.12.5.1.1 Channel attenuation in logarithmic format (HLOGps) For each subcarrier where the HLOGps_ds accuracy requirement applies, and where HLOGps_reference_ds is above 90 d
24、B, the absolute error (between the HLOGps_ds and the HLOGps_reference_ds) shall be equal to or smaller than 3.0 dB. Requirements for the mean absolute error of HLOGps_ds reported values are for further study. Accuracy requirements related to the difference over adjacent subcarriers of the absolute e
25、rror (between the HLOGps_ds and the HLOGps_reference_ds) are for further study. The HLOGps_ds accuracy requirements shall apply to HLOGps_ds measured in either initialization or in diagnostic mode. For each subcarrier where the HLOGps_us accuracy requirement applies (based on its subcarrier index an
26、d SNRps_us value only, and not considering restrictions related to its Zloopvalue), and where HLOGps_reference_us is above 90 dB, an HLOGps_us value different from the special value defined in clause 8.12.3.1 shall be reported. For each subcarrier where the HLOGps_us accuracy requirement applies, an
27、d where HLOGps_reference_us is above 90 dB, the absolute error (between the HLOGps_us and the HLOGps_reference_us) shall be equal to or smaller than 3.0 dB. Requirements for the mean absolute error of HLOGps_us reported values are for further study. Accuracy requirements related to the difference ov
28、er adjacent subcarriers of the absolute error (between the HLOGps_us and the HLOGps_reference_us) are for further study. The HLOGps_us accuracy requirements shall apply to HLOGps_us measured in either initialization or in diagnostic mode. 2 Rec. ITU-T G.992.3 (2009)/Amd.5 (10/2012) 8.12.5.1.2 Channe
29、l attenuation in complex format (HLINps) The HLINps reference value and HLINps accuracy requirements are for further study. The accuracy requirements for the magnitude of HLINps are the same as those for HLOGps in clause 8.12.5.1.1. There is no accuracy requirement for the phase of HLINps. 3) Change
30、s to clauses 8.12.5.4 and 8.12.5.5 Introduce the changes shown below to clauses 8.12.5.4 and 8.12.5.5. 8.12.5.4 Loop attenuation (LATN) For further study. The downstream loop attenuation (LATNds) reference value shall be defined as follows: =DNSCknnk_)(e_dsH_referenclog10ence_dsLATN_refer21210where
31、NSC_D is the number of subcarriers in the downstream band = n2n1+1 where n1 and n2 are the indices of the first and the last subcarriers of this band, respectively; and H_reference_ds is defined as follows: |H_reference_ds(k)|2= 10HLOGps_reference_ds(k)/10= 10(PSDps_UR2(k) (REFPSDds + log_tssi(k)/10
32、where PSDps_UR2(i) is the downstream PSD measured at the U-R2 reference point, after initialization of the line up to a C-REVERB state, in which state the ATU-C is frozen and the ATU-R subsequently replaced by an RN= 100 . The upstream loop attenuation (LATNus) reference value shall be defined as fo
33、llows: =UNSCknnk_)(e_usH_referenclog10ence_usLATN_refer43210where NSC_U is the number of subcarriers in the upstream band = n4n3+1 where n3 and n4 are the indices of the first and the last subcarriers of this band, respectively; and H_reference_us is defined as: |H_reference_us(k)|2= 10HLOGps_refere
34、nce_us(k)/10= 10(PSDps_UC2(k) (REFPSDus + log_tssi(k)/10where PSDps_UC2(i) is the upstream PSD measured at the U-C2 reference point, after initialization of the line up to an R-REVERB state, in which state the ATU-R is frozen and the ATU-C subsequently replaced by an RN= 100 . If one or more H_refer
35、ence values could not be measured because they are out of the PSD mask passband (as relevant to the chosen application option see annexes) (see clause 8.12.3.1), then the LATN_reference shall be calculated as an average of H_reference values over a number of subcarriers that is less than NSC_D or NS
36、C_U: Rec. ITU-T G.992.3 (2009)/Amd.5 (10/2012) 3 =_)(e_dsH_referenclog10ence_dsLATN_refer_210DNSCkreferenceHvalidkwhere NSC_D is the number of valid downstream H_reference values. =_)(e_usH_referenclog10ence_usLATN_refer_210UNSCkreferenceHvalidkwhere NSC_U is the number of valid upstream H_reference
37、 values. The absolute error between LATN_ds and LATN_reference_ds shall be equal to or smaller than 3 dB. The absolute error between LATN_us and LATN_reference_us shall be equal to or smaller than 3 dB. The accuracy requirements shall apply to its measurement either during initialization or in the l
38、oop diagnostics mode. 8.12.5.5 Signal attenuation (SATN) For further study. The reference value for the downstream signal attenuation SATNds shall be defined as: SATN_reference_ds = TXpower_dBm_reference_ds RXpower_dBm_reference_ds The TXpower_dBm_reference_ds is: TXpower_dBm_reference_ds = NOMATPds
39、 PCBds where REFPSDi is the value of REFPSDds for subcarrier i in dBm/Hz, giis the fine tune gain defined in clause 8.6.4, and f is the subcarrier spacing in Hz. The RXpower_dBm_reference_ds is: RXpower_dBm_reference_ds = 10 log10MEDLEYds210i)PSDps_UR2(10iig where PSDps_UR2(i) is the downstream PSD
40、measured at the U-R2 reference point, after initialization of the line up to a C-REVERB state, in which state the ATU-C is frozen and the ATU-R subsequently replaced by an RN= 100 . The reference value for the upstream signal attenuation SATNus shall be defined as: SATN_reference_us = TXpower_dBm_re
41、ference_us RXpower_dBm_reference_us The TXpower_dBm_reference_us is: TXpower_dBm_reference_us = NOMATPus PCBus where REFPSDi is the value of REFPSDus for subcarrier i in dBm/Hz, giis the fine tune gain defined in clause 8.6.4, and f is the subcarrier spacing in Hz. The RXpower_dBm_reference_us is: R
42、Xpower_dBm_reference_us = 10 log10MEDLEYus210i)PSDps_UC2(10iig 4 Rec. ITU-T G.992.3 (2009)/Amd.5 (10/2012) where PSDps_UC2(i) is the upstream PSD measured at the U-C2 reference point, after initialization of the line up to an R-REVERB state, in which state the ATU-R is frozen and the ATU-C subsequen
43、tly replaced by an RN= 100 . NOTE The feature to freeze an ATU in a REVERB state exists solely to allow a test bed to be constructed for the purpose of measuring the HLOGps reference value. It applies only to specific transceivers serving as the “transmit transceiver“ of the test environment, and is
44、 not a requirement for compliance to this Recommendation. The absolute error between SATNds and SATN_reference_ds shall be equal to or smaller than 3 dB. The absolute error between SATNus and SATN_reference_us shall be equal to or smaller than 3 dB. The accuracy requirements for SATNds and SATNus sh
45、all apply to their measurement either during initialization, diagnostic mode, and showtime. Printed in Switzerland Geneva, 2013 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
46、 operation and human factors Series F Non-telephone telecommunication services Series G Transmission systems and media, digital systems and networks Series H Audiovisual and multimedia systems Series I Integrated services digital network Series J Cable networks and transmission of television, sound
47、programme and other multimedia signals Series K Protection against interference Series L Construction, installation and protection of cables and other elements of outside plant Series M Telecommunication management, including TMN and network maintenance Series N Maintenance: international sound prog
48、ramme and television transmission circuits Series O Specifications of measuring equipment Series P Terminals and subjective and objective assessment methods Series Q Switching and signalling Series R Telegraph transmission Series S Telegraph services terminal equipment Series T Terminals for telemat
49、ic 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
