Recommendation ITU-T G.993.5 Corrigendum 1 (03/2020) Self-FEXT cancellation (vectoring) for use with VDSL2 transceivers
Summary
History
FOREWORD
Table of Contents
Corrigendum 1
1 Scope
2 References
3 Definitions
     3.1 Terms defined elsewhere
     3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Reference models
     5.1 General
     5.2 Downstream vectoring
     5.3 Upstream vectoring
6 CO-side requirements in a vectored group
     6.1 General
     6.2 Downstream vectoring requirements for the VTU-O
          6.2.1 Synchronous mode
          6.2.2 Sync symbol position
          6.2.3 Modulation of a pilot sequence
          6.2.4 Pre-coding
          6.2.5 Transceiver states and transceiver state diagram (replaces clause 12.1.2 of [ITU-T G.993.2])
     6.3 Upstream vectoring requirements for the VTU-O
     6.4 Requirements for the VCE
7 CP-side requirements in a vectored group
     7.1 General
     7.2 Downstream vectoring requirements for the VTU-R
          7.2.1 Definition of normalized error sample
          7.2.2 Reporting of clipped error samples
               7.2.2.1 Control parameters for clipped error sample reporting
               7.2.2.2 Grouping of clipped error samples
          7.2.3 Backchannel format
               7.2.3.1 Format of the ERB
               7.2.3.2 Format of the error block
               7.2.3.3 Backchannel data rate (informative)
          7.2.4 Identification of the ERB during Showtime
     7.3 Upstream vectoring requirements for the VTU-R
          7.3.1 Symbol alignment
          7.3.2 Sync symbol position
          7.3.3 Modulation of pilot sequence
     7.4 Requirements for the NT system
          7.4.1 Layer 2 Ethernet encapsulation of the backchannel data
          7.4.2 eoc encapsulation of the backchannel data
8 Vectoring-specific eoc messages
     8.1 eoc messages for backchannel configuration
     8.2 Pilot sequence update command and response
     8.3 Power management commands and responses
          8.3.1 L3 Request by VTU-R (replaces clause 11.2.3.9.1 of [ITU-T G.993.2])
          8.3.2 L3 Request by VTU-O (replaces clause 11.2.3.9.2 of [ITU-T G.993.2])
9 Activation and deactivation of pairs in a vectored group
     9.1 Orderly shutdown event
     9.2 Disorderly shutdown event
10 Initialization of a vectored group
     10.1 Overview
     10.2 ITU-T G.994.1 Handshake phase
          10.2.1 Avoidance of false initialization in crosstalk environment
     10.3 Channel Discovery phase
          10.3.1 Overview
          10.3.2 Modified SOC messages sent during Channel Discovery phase
               10.3.2.1 O-SIGNATURE
               10.3.2.2 R-MSG1
          10.3.3 Vectoring-specific VTU-O signals transmitted during the Channel Discovery phase
               10.3.3.1 O-P-VECTOR 1
               10.3.3.2 O-P-CHANNEL DISCOVERY V1
               10.3.3.3 O-P-SYNCHRO V1
               10.3.3.4 O-P-CHANNEL DISCOVERY 1 and O-P-CHANNEL DISCOVERY 2
               10.3.3.5 Downstream sync symbol and upstream pilot sequence markers
               10.3.3.6 Initialization of multiple initializing lines
          10.3.4 Vectoring specific VTU-R signals transmitted during Channel Discovery phase
               10.3.4.1 R-P-VECTOR 1
     10.4 Training phase
          10.4.1 Overview
          10.4.2 Modified SOC messages sent during the Training phase
               10.4.2.1 O-TA_UPDATE
               10.4.2.2 R-ERROR-FEEDBACK
          10.4.3 Vectoring specific VTU-O signals transmitted during the Training phase
               10.4.3.1 O-P-VECTOR 1-1
               10.4.3.2 O-P-TRAINING V1
               10.4.3.3 O-P-SYNCHRO V2
               10.4.3.4 O-P-TRAINING 1 and O-P-TRAINING 2
               10.4.3.5 O-P-VECTOR 2
               10.4.3.6 O-P-SYNCHRO V3
               10.4.3.7 O-P-VECTOR 2-1
               10.4.3.8 O-P-SYNCHRO V4
               10.4.3.9 Initialization of multiple initializing lines
          10.4.4 Vectoring specific VTU-R signals transmitted during the Training phase
               10.4.4.1 R-P-QUIET V1
               10.4.4.2 R-P-VECTOR 1-1
               10.4.4.3 R-P-VECTOR 1-2
               10.4.4.4 R-P-SYNCHRO V1
               10.4.4.5 R-P-VECTOR 2
               10.4.4.6 R-P-SYNCHRO V2
     10.5 Channel Analysis and Exchange phase
          10.5.1 Overview
          10.5.2 Modified SOC messages sent during Channel Analysis and Exchange phase
               10.5.2.1 O-PMS
     10.6 Transition from initialization to Showtime
     10.7 Loop diagnostic mode procedures
          10.7.1 Overview
               10.7.1.1 SOC message mapping during loop diagnostic mode
          10.7.2 Channel discovery and training phases of loop diagnostic mode
               10.7.2.1 SOC messages exchanged during the channel discovery and training phases of loop diagnostic mode
                    10.7.2.1.1 O-PRM & R-PRM
                    10.7.2.1.2 R-MSG1 (supplements clause 10.3.2.2)
                    10.7.2.1.3 O-TA_UPDATE (supplements clause 10.4.2.1)
               10.7.2.2 Signals transmitted during the channel discovery and training phases
                    10.7.2.2.1 R-P-VECTOR 2 (replaces clause 10.4.4.5)
          10.7.3 Channel Analysis and Exchange phase of loop diagnostic mode
11 Configuration and test parameters
     11.1 Configuration parameters
          11.1.1 FEXT cancellation enable/disable
          11.1.2 FEXT cancellation not required frequency bands
          11.1.3 Target NDR/target ETR
               11.1.3.1 Target NDR
               11.1.3.2 Target ETR
          11.1.4 Line priorities
          11.1.5 Requested Xlin subcarrier group size (XLINGREQ)
     11.2 Test parameters
          11.2.1 FEXT downstream coupling coefficients (Xlinpsds)
               11.2.1.1 Definition of downstream FEXT coupling coefficients (Xlinpsds)
               11.2.1.2 Reporting of downstream FEXT coupling coefficients (Xlinpsds)
          11.2.2 FEXT upstream coupling coefficients (Xlinpsus)
               11.2.2.1 Definition of upstream FEXT coupling coefficients (Xlinpsus)
               11.2.2.2  Reporting of upstream FEXT coupling coefficients (Xlinpsus)
Annex A  Mitigating strong FEXT
     A.1 Introduction
     A.2 Control parameters for the minimum message overhead data rate (amends clause 9.5.4 of [ITU-T G.993.2])
     A.3 Clipped error samples
          A.3.1 Definition of clipped error sample (replaces clause 3.2.4)
          A.3.2 Control parameters for clipped error sample reporting (amends clause 7.2.2.1)
          A.3.3 Definition of normalized error sample (amends clause 7.2.1)
     A.4 OLR commands
     A.5 ITU-T G.994.1 Handshake phase (amends clause 10.2)
     A.6 TIGAV functionality
          A.6.1 TIGAV and TIGAVRESP commands
               A.6.1.1 Parameters of the TIGAV command
               A.6.1.2 Parameters controlled by the TIGAVRESP command
               A.6.1.3 Interpolation of the ri values
          A.6.2 TIGAV procedure
               A.6.2.1 Definition of TIGAV-SYNCHRO pattern
               A.6.2.2 Implementing the TIGAV gain modification by the VTU-R
               A.6.2.3 Relation TIGAV and subsequent autonomous SRA in downstream
     A.7 Main body amendments related to MREFPSD
          A.7.1 Definitions (replaces clauses 3.31 and 3.32 of [ITU-T G.993.2])
          A.7.2 Nominal aggregate transmit power (NOMATP) (replaces clause 10.3.4.2.1 of [ITU-T G.993.2])
          A.7.3 Frequency-domain transmit spectrum shaping (tssi) (replaces clause 10.3.4.3 of [ITU-T G.993.2])
          A.7.4 General (amends clause 6.1 of ITU-T G.993.5)
          A.7.5 PSD and PSD mask summary (amends clause 7.2.3 of [ITU-T G.993.2])
          A.7.6 Channel characteristics function per subcarrier group (CCF-ps) (amends clause 11.4.1.1.1 of [ITU-T G.993.2])
          A.7.7 PMD Test Parameter Read commands and responses (replaces clause 11.2.3.11 of [ITU-T G.993.2])
          A.7.8 Signal attenuation per band (SATN-pb) (replaces clause 11.4.1.1.5 of [ITU-T G.993.2])
          A.7.9 Status parameter GAINSpsds
     A.8 Management
          A.8.1 Configuration parameters
               A.8.1.1 STRONGFEXT mode (STRONGFEXT_MODE)
          A.8.2 Status parameters
               A.8.2.1 Actual STRONGFEXT mode (STRONGFEXT_MODE_ACTUAL)
          A.8.3 Inventory parameters
               A.8.3.1 STRONGFEXT mode support (STRONGFEXT_MODE_SUPPORT_O/R)
Annex B  Vectored long reach VDSL2
     B.1 Introduction
     B.2 Overview of the initialization procedure
     B.3 ITU-T G.994.1 Handshake phase
     B.4 Signals sent by the VTU-O during the Channel Discovery and Training phase
          B.4.1 O-P-QUIET 1
          B.4.2 O-P-VECTOR 0
          B.4.3 O-P-PROBING-LR
          B.4.4 O-P-QUIET 1-LR
          B.4.5 O-P-VECTOR 1-LR
          B.4.6 O-P-TRAINING-LR
          B.4.7 O-P-VECTOR 1
          B.4.8 The G.993.5 Channel Discovery phase
               B.4.8.1 O-SIGNATURE (amends clause 12.3.3.2.1.1 of [ITU-T G.993.2])
               B.4.8.2 O-UPDATE (amends clause 12.3.3.2.1.2 of [ITU-T G.993.2])
               B.4.8.3 O-PRM (amends clause 12.3.3.2.1.3 of [ITU-T G.993.2])
          B.4.9 The ITU-T G.993.5 Training phase
     B.5 Signals sent by the VTU-R during the Channel Discovery and Training phase
          B.5.1 R-P-QUIET 1
          B.5.2 R-P-PROBING-LR
          B.5.3 R-P-QUIET 1-LR
          B.5.4 R-P-QUIET 2-LR
          B.5.5 R-P-TRAINING-LR
          B.5.6 The ITU-T G.993.5 Channel Discovery phase
               B.5.6.1 R-UPDATE (amends clause 12.3.3.2.2.2 of [ITU-T G.993.2])
          B.5.7 ITU-T G.993.5 Training phase
     B.6 O/R-P-PROBING-LR signal exchange
          B.6.1 O-P-PROBING-LR signals
               B.6.1.1 Transmit PSD of the O-P-PROBING-LR signals
               B.6.1.2 Symbol definitions for the O-P-PROBING-LR signals
               B.6.1.3 O-P-COMB 2-LR
               B.6.1.4 O-P-QUIET 3-LR
               B.6.1.5 O-P-COMB 3-LR
               B.6.1.6 O-P-ICOMB 2-LR
               B.6.1.7 O-P-QUIET 4-LR
               B.6.1.8 O-P-COMB 4-LR
               B.6.1.9 O-P-ICOMB 4-LR
               B.6.1.10 O-P-MSG-PCB-LR
          B.6.2 R-P-PROBING-LR signals
               B.6.2.1 Transmit PSD of the R-P-PROBING-LR signals
               B.6.2.2 Symbol definitions for the R-P-PROBING-LR signals
               B.6.2.3 R-P-COMB 2-LR
               B.6.2.4 R-P-ICOMB 1-LR
               B.6.2.5 R-P-LINEPROBE-LR
               B.6.2.6 R-P-QUIET 3-LR
               B.6.2.7 R-P-COMB 3-LR
               B.6.2.8 R-P-ICOMB 2-LR
               B.6.2.9 R-P-MSG-PCB-LR
               B.6.2.10 R-P-QUIET 4-LR
          B.6.3 Timeline of O/R-P-PROBING-LR signals
     B.7 O/R-P-TRAINING-LR signal exchange
          B.7.1 O-P-TRAINING-LR signals
               B.7.1.1 Transmit PSD of the O-P-TRAINING-LR signals
               B.7.1.2 Symbol definitions for the O-P-TRAINING-LR signals
               B.7.1.3 O-P-REVERB 0-LR
               B.7.1.4 O-P-QUIET 5-LR
               B.7.1.5 O-P-REVERB 1-LR
               B.7.1.6 O-P-TREF 1-LR
               B.7.1.7 O-P-REVERB 2-LR
               B.7.1.8 O-P-ECT-LR
               B.7.1.9 O-P-REVERB 3-LR
               B.7.1.10 O-P-TREF 2-LR
               B.7.1.11 O-P-QUIET 6-LR
               B.7.1.12 O-P-REVERB 4-LR
               B.7.1.13 O-P-SEGUE 1-LR
               B.7.1.14 O-P-PILOT-LR
          B.7.2 R-P-TRAINING-LR signals
               B.7.2.1 Transmit PSD of the R-P-TRAINING-LR signals
               B.7.2.2 Symbol definitions for the R-P-TRAINING-LR signals
               B.7.2.3 R-P-REVERB 1-LR
               B.7.2.4 R-P-REVERB 2-LR
               B.7.2.5 R-P-QUIET 5-LR
               B.7.2.6 R-P-REVERB 3-LR
               B.7.2.7 R-P-ECT-LR
               B.7.2.8 R-P-REVERB 4-LR
               B.7.2.9 R-P-SEGUE 1-LR
          B.7.3 Timeline of O/R-P-TRAINING-LR signals
     B.8 ITU-T G.993.5 Channel Discovery phase and Training phase in long loop operation
          B.8.1 ITU-T G.993.5 Channel Discovery phase in long loop operation
               B.8.1.1 Transition to ITU-T G.993.5 Channel Discovery phase
               B.8.1.2 Use of PILOT during R-P-LINEPROBE
               B.8.1.3 Replacement of R-P-VECTOR signals
               B.8.1.4 O-SIGNATURE (amends clause 12.3.3.2.1.1 of [ITU-T G.993.2])
               B.8.1.5 PSD adjustments during ITU-T G.993.5 Channel Discovery phase
          B.8.2 ITU-T G.993.5 Training phase in long loop operation
               B.8.2.1 Replacement of R-P-VECTOR signals
     B.9 Definition of limit PSD masks
          B.9.1 Operation according to Annex A [ITU-T G.993.2]
          B.9.2 Operation according to Annex B of [ITU-T G.993.2]
               B.9.2.1 Downstream Limit PSD mask and maximum aggregate transmit power
               B.9.2.2 Upstream limit PSD mask
          B.9.3 Operation according to Annex C of [ITU-T G.993.2]
          B.9.4 Operation according to Annex N of [ITU-T G.993.2]
     B.10 Management
          B.10.1 Configuration parameters
               B.10.1.1 VDSL2-LR enable (VDSL2-LR_ENABLE)
               B.10.1.2 Downstream maximum nominal power spectral density (MAXNOMPSDds)
               B.10.1.3 Upstream maximum nominal power spectral density (MAXNOMPSDus)
               B.10.1.4 Downstream PSD Mask (MIBMASKds) (amends clause 7.2.1.1 of [ITU-T G.993.2])
               B.10.1.5 VDSL2 PSD mask class selection (CLASSMASK)
               B.10.1.6 Downstream maximum nominal aggregate transmit power (MAXNOMATPds)
               B.10.1.7 Upstream maximum nominal aggregate transmit power (MAXNOMATPus)
          B.10.2 Status parameters
               B.10.2.1 VDSL2-LR actual operation type (VDSL2-LR_ACTOPTYPE)
          B.10.3 Inventory parameters
               B.10.3.1 VDSL2-LR support (VDSL2-LR_SUPPORT_O/R)
          B.10.4 Test parameters
               B.10.4.1 Test parameter group size
     B.11 Nominal aggregate transmit power (NOMATP) (replaces clause 10.3.4.2.1 of [ITU-G.993.2])
Appendix I  Crosstalk channel modelling
     I.1 Scope
     I.2 Purpose
     I.3 MIMO crosstalk channel model A
     I.4 MIMO crosstalk channel model C
          I.4.1 Assumptions to crosstalk model
          I.4.2 Generation of a sample value for FEXT coupling loss
          I.4.3 FEXT coupling channel transfer function
Appendix II  Examples of VCE control of initialization process in the activation of multiple lines in the vectored group
     II.1 Introduction
     II.2 VCE handling two groups of initializing lines
     II.3 VCE using handshake capabilities
Appendix III  SNR-based FEXT channel estimation method
     III.1 Tools
     III.2 Estimation of FEXT channels from a new line into existing lines
          III.2.1 Introduction
          III.2.2 Probing signal
          III.2.3 Graphical representation
          III.2.4 Derivation of the equations for crosstalk channel estimation
          III.2.5 Equations for crosstalk channel estimation
          III.2.6 Crosstalk channel estimation algorithm
          III.2.7 Extended equations applicable while performing pre-compensation
     III.3 Estimation of FEXT channels from existing lines into a new line
          III.3.1 Introduction
          III.3.2 Probing signal
          III.3.3 Derivation of the equations for crosstalk channel estimation
          III.3.4 Crosstalk channel estimation algorithm
Bibliography