1、 International Telecommunication Union ITU-T G.993.2TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Corrigendum 1(06/2012) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Access networks Very high speed digital subscriber line transceiv
2、ers 2 (VDSL2) Corrigendum 1 Recommendation ITU-T G.993.2 (2011) 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 SY
3、STEMS 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 A
4、ND 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.919 Digital secti
5、ons 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 digital transmissio
6、n 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 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CH
7、ARACTERISTICS 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.993.2 (2011)/Cor.1 (06/2012) i Recommendation ITU-T G.993.2 Very hi
8、gh speed digital subscriber line transceivers 2 (VDSL2) Corrigendum 1 Summary Corrigendum 1 to Recommendation ITU-T G.993.2 (2011) covers the following functionalities: Handshake bits for downstream and full ITU-T G.993.5-friendly operation (corrigendum). CIpolicy=2 (corrigendum). O-SIGNATURE (corri
9、gendum). Annex N (corrigendum). Annex O (corrigendum). History Edition Recommendation Approval Study Group 1.0 ITU-T G.993.2 2006-02-17 15 1.1 ITU-T G.993.2 (2006) Cor. 1 2006-12-14 15 1.2 ITU-T G.993.2 (2006) Amd. 1 2007-04-06 15 1.3 ITU-T G.993.2 (2006) Amd. 1 Cor. 1 2007-07-29 15 1.4 ITU-T G.993.
10、2 (2006) Cor. 2 2007-07-29 15 1.5 ITU-T G.993.2 (2006) Amd. 2 2008-02-06 15 1.6 ITU-T G.993.2 (2006) Amd. 3 2008-08-22 15 1.7 ITU-T G.993.2 (2006) Amd. 4 2009-01-13 15 1.8 ITU-T G.993.2 (2006) Cor. 3 2009-06-29 15 1.9 ITU-T G.993.2 (2006) Amd. 5 2010-04-22 15 1.10 ITU-T G.993.2 (2006) Amd. 6 2010-11
11、-29 15 1.11 ITU-T G.993.2 (2006) Cor. 4 2011-04-13 15 1.12 ITU-T G.993.2 (2006) Amd. 7 2011-06-22 15 2.0 ITU-T G.993.2 2011-12-16 15 2.1 ITU-T G.993.2 (2011) Amd. 1 2012-04-06 15 2.2 ITU-T G.993.2 (2011) Cor. 1 2012-06-13 15 ii Rec. ITU-T G.993.2 (2011)/Cor.1 (06/2012) FOREWORD The International Tel
12、ecommunication 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, operating and
13、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, produce Rec
14、ommendations 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 this Recom
15、mendation, 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., interoper
16、ability 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 that c
17、ompliance 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 evidence, vali
18、dity 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 received notice of intellectual property, protected by patents, which may be required
19、 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 2012 All rights reserved. No part of this publication may be reproduced,
20、by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.993.2 (2011)/Cor.1 (06/2012) iii Table of Contents Page 1) Handshake bits for downstream and full ITU-T G.993.5-friendly operation . 1 2) CIpolicy=2 4 3) O-SIGNATURE . 5 4) Annex N 5 5) Annex O 13 Rec. ITU-T G.993.2 (
21、2011)/Cor.1 (06/2012) 1 Recommendation ITU-T G.993.2 Very high speed digital subscriber line transceivers 2 (VDSL2) Corrigendum 1 1) Handshake bits for downstream and full ITU-T G.993.5-friendly operation 12.3.2 ITU-T G.994.1 handshake phase Change Table 12-7 as follows: Table 12-7 VTU-O CL message
22、NPar(2) bit definitions ITU-T G.994.1 NPar(2) Bit Definition of NPar(2) bit All-digital mode If set to ONE, signifies that the VTU-O supports all-digital mode. Support of downstream virtual noise If set to ONE, signifies that the VTU-O supports the use of the downstream virtual noise mechanism. Line
23、probe Always set to ONE in a VTU-O CL message. Loop Diagnostic mode Set to ONE if the VTU-O requests loop diagnostic mode. Support of PSD shaping in US0 Always set to ONE in a VTU-O CL message. Support of equalized FEXT UPBO If set to ONE, signifies that the VTU-O supports equalized FEXT UPBO. ITU-T
24、 G.993.5-friendly ITU-T G.993.2 operation in the downstream direction If set to ONE, signifies that VTU-O supports Annex N. See Annex L, Table L.12-3 Full ITU-T G.993.5-friendly ITU-T G.993.2 operation If set to ONE, signifies that VTU-O supports Annex O. Alternative electrical length estimation met
25、hod If set to ONE, signifies that the VTU-O supports the Alternative Electrical Length Estimation Method (ELE-M1) Change Table 12-10 as follows: Table 12-10 VTU-O MS message NPar(2) bit definitions ITU-T G.994.1 NPar(2) Bit Definition of NPar(2) bit All-digital mode Set to ONE if and only if both th
26、e last previous CLR and the last previous CL messages have set this bit to ONE. If set to ONE, indicates that both the VTU-O and the VTU-R shall be configured for operation in all-digital mode. Support of downstream virtual noise Set to ONE if and only if both the last previous CLR and the last prev
27、ious CL messages have set this bit to ONE. Indicates that the downstream virtual noise mechanism may be used. 2 Rec. ITU-T G.993.2 (2011)/Cor.1 (06/2012) Table 12-10 VTU-O MS message NPar(2) bit definitions ITU-T G.994.1 NPar(2) Bit Definition of NPar(2) bit Lineprobe Set to ONE if and only if both
28、the last previous CLR and the last previous CL messages have set this bit to ONE. Indicates that the channel discovery phase of initialization shall include a lineprobe stage. Loop Diagnostic mode Set to ONE if either the last previous CLR or the last previous CL message has set this bit to ONE. Ind
29、icates that both VTUs shall enter loop diagnostic mode. Support of PSD shaping in US0 Set to ONE if and only if both the last previous CLR and the last previous CL messages have set this bit to ONE. Indicates that the VTU-R supports PSD shaping in the US0 band. Support of equalized FEXT UPBO Set to
30、ONE if and only if both the last previous CLR and the last previous CL messages have set this bit to ONE. Indicates that both the VTU-O and the VTU-R shall use equalized FEXT UPBO. ITU-T G.993.5-friendly ITU-T G.993.2 operation in the downstream direction See Table N.2 Full ITU-T G.993.5-friendly IT
31、U-T G.993.2 operation See Table O.2. Alternative Electrical Length Estimation Method Set to ONE if and only if both the last previous CLR and the last previous CL messages have set this bit to ONE. Indicates that both the VTU-O and the VTU-R shall use electrical length estimation method ELE-M1. Chan
32、ge Table 12-13 as follows: Table 12-13 VTU-R CLR message NPar(2) bit definitions ITU-T G.994.1 NPar(2) Bit Definition of NPar(2) bit All-digital mode If set to ONE, signifies that the VTU-R supports all-digital mode. Support of downstream virtual noise If set to ONE, signifies that the VTU-R support
33、s the use of the downstream virtual noise mechanism. Lineprobe Set to ONE if the VTU-R requests the inclusion of a lineprobe stage in initialization. Loop Diagnostic mode Set to ONE if the VTU-R requests loop diagnostic mode. Support of PSD shaping in US0 If set to ONE, signifies that the VTU-R supp
34、orts PSD shaping in the US0 band. Support of equalized FEXT If set to ONE, signifies that the VTU-R supports equalized FEXT UPBO. ITU-T G.993.5-friendly ITU-T G.993.2 operation in the downstream direction If set to ONE, signifies that the VTU-R supports Annex N. See Table N.3 Full ITU-T G.993.5-frie
35、ndly ITU-T G.993.2 operation If set to ONE, signifies that VTU-R supports Annex O. Rec. ITU-T G.993.2 (2011)/Cor.1 (06/2012) 3 Table 12-13 VTU-R CLR message NPar(2) bit definitions ITU-T G.994.1 NPar(2) Bit Definition of NPar(2) bit Alternative electrical length estimation method If set to ONE, sign
36、ifies that the VTU-R supports the Alternative Electrical Length Estimation Method (ELE-M1) Change Table 12-16 as follows: Table 12-16 VTU-R MS message NPar(2) bit definitions ITU-T G.994.1 NPar(2) Bit Definition of NPar(2) bit All-digital mode Set to ONE if and only if both the last previous CLR and
37、 the last previous CL messages have set this bit to ONE. If set to ONE, indicates that both the VTU-O and the VTU-R shall be configured for operation in all-digital mode. Support of downstream virtual noise Set to ONE if and only if both the last previous CLR and the last previous CL messages have s
38、et this bit to ONE. Indicates that the downstream virtual noise mechanism may be used. Lineprobe Set to ONE if and only if both the last previous CLR and the last previous CL messages have set this bit to ONE. Indicates that the channel discovery phase of initialization shall include a lineprobe sta
39、ge. Loop Diagnostic mode Set to ONE if either the last previous CLR or the last previous CL message has set this bit to ONE. Indicates that both VTUs shall enter loop diagnostic mode. Support of PSD shaping in US0 Set to ONE if and only if both the last previous CLR and the last previous CL messages
40、 have set this bit to ONE. Indicates that the VTU-R shall support PSD shaping in the US0 band. Support of equalized FEXT Set to ONE if and only if both the last previous CLR and the last previous CL messages have set this bit to ONE. Indicates that both the VTU-O and the VTU-R shall use equalized FE
41、XT UPBO. ITU-T G.993.5-friendly ITU-T G.993.2 operation in the downstream direction See Table N.4 Full ITU-T G.993.5-friendly ITU-T G.993.2 operation See Table O.4. Alternative electrical length estimation method Set to ONE if and only if both the last previous CLR and the last previous CL messages
42、have set this bit to ONE. Indicates that both the VTU-O and the VTU-R shall use ELE-M1. 4 Rec. ITU-T G.993.2 (2011)/Cor.1 (06/2012) 2) CIpolicy=2 Change clause 12.3.5.2.1.2 as follows: 12.3.5.2.1.2 O-TPS The field “TPS-TC options“ shall be coded as follows: Bit 0: The bit shall be set to ONE to enab
43、le pre-emption in this bearer, if and only if the bit was set to ONE for this bearer in both O-MSG 1 and R-MSG 2. Bit 1: The bit shall be set to ONE to enable short packets in this bearer, if and only if the bit was set to ONE for this bearer in both O-MSG 1 and R-MSG 2. For a bearer mapped to an AT
44、M or STM TPS-TC, bits 0 and 1 of the TPS-TC options field are reserved by ITU-T and shall be set to ZERO. For the upstream bearer channel(s), bits 2-7 shall be set to ZERO. For the downstream bearer channel(s), bits 2-7 shall be coded as follows: Bits 3-2 contains the selection of the CIpolicy that
45、shall be used in the downstream direction. A value of ZERO002indicates that the mandatory CIpolicy shall be used. A value of ONE012indicates that the optional CIpolicy 1 (see clause 12.3.7) shall be used. A value of 102indicates that the optional CIpolicy 2 (see clause 12.3.7) shall be used. The CO
46、shall only select optional CIpolicies for which the VTU-R has indicated support (see clause 12.3.5.2.2.1). A value of ONEdifferent from 002can only be selected if no more than one bearer channel is active. Bit 3 is reserved by ITU-T and set to ZERO. Bit 4 contains the selection of the Re-Initializat
47、ion Policy that shall be used in the downstream direction for that bearer channel (RIpolicydsn). A value of ZERO indicates that the mandatory Re-Initialization Policy 0 shall be used. A value of ONE indicates that the optional Re-Initialization Policy 1 (see clause 12.1.4) shall be used. The same va
48、lue shall be indicated for all bearer channels. The CO shall only select optional Re-Initialization Policies for which the VTU-R has indicated support (see clause 12.3.5.2.2.1). Bits 5-7 are reserved by the ITU-T and shall be set to ZERO. Change clause 12.3.5.2.2.1 as follows: 12.3.5.2.2.1 R-MSG 2 T
49、he field “TPS-TC options“ shall be coded as follows: Bit 0: If the VTU-R supports pre-emption in this bearer (N.3.1.2 of ITU-T G.992.3), the bit shall be set to ONE. Bit 1: If the VTU-R supports short packets in this bearer (N.3.1.3 of ITU-T G.992.3), the bit shall be set to ONE. For a bearer mapped to an ATM or STM TPS-TC, bits 0 and 1 shall be set to ZERO at the transmitter and ignored by the receiver. Bit 2 indicates whether the optional channel initialization policy 1 is supported for that bearer channel
