Recommendation ITU-T G.9701 Amendment 3 (10/2020) Fast access to subscriber terminals (G.fast) – Physical layer specification 
Summary
History
FOREWORD
Table of Contents
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 and system requirements
     5.1 System reference models
     5.2 Application reference models
     5.3 FTU protocol reference model
     5.4 FTU functional model
     5.5 INP system requirements
6 Profiles
     6.1 Definition
     6.2 Profile compliance
7 Transmission medium interface characteristics
     7.1 Duplexing method
     7.2 Frequency band
     7.3 Power spectral density
          7.3.1 Transmit PSD mask
               7.3.1.1 MIBPSDMASK construction
                    7.3.1.1.1 Overview
                    7.3.1.1.2 Definition of breakpoints
                         7.3.1.1.2.1 Definition of breakpoints for PSD shaping other than LESM
                         7.3.1.1.2.2 Definition of the breakpoints for the LESM
                              7.3.1.1.2.2.1 One-slope steep upward shape
                         7.3.1.1.2.3 Definition of breakpoints at the edge of a band
               7.3.1.2 Notching of specific frequency bands
               7.3.1.3 Subcarrier masking
               7.3.1.4 Upstream power back-off (UPBO)
                    7.3.1.4.1 UPBO mechanism
                    7.3.1.4.2 UPBO PSD mask
                         7.3.1.4.2.1 Electrical length estimation
                         7.3.1.4.2.2 Computation of UPBOMASK
               7.3.1.5 LPM classes
          7.3.2 PSD and PSD mask summary
     7.4 Out-of-band PSD limit
     7.5 Termination impedance
     7.6 Maximum aggregate transmit power
          7.6.1 Maximum aggregate transmit power
8 Transport protocol specific transmission convergence (TPS-TC) function
     8.1 Functional reference model
          8.1.1 γ reference point
          8.1.2 α reference point
          8.1.3 TPS-TC_MGMT interface
     8.2 Generic DTU format
          8.2.1 DTU header
               8.2.1.1 Sequence identifier (SID) field
               8.2.1.2 Time stamp (TS) field
               8.2.1.3 Auxiliary field
          8.2.2 DTU payload
          8.2.3 Error check sequence (ECS)
     8.3 Packet-based TPS-TC (PTM-TC)
          8.3.1 PTM-TC DTU format
     8.4 Network timing reference (NTR)
          8.4.1 NTR transport
               8.4.1.1 NTR frequency synchronization
     8.5 Time-of-day (ToD)
          8.5.1 Time-of-day distribution operational overview
          8.5.2 ToD frequency synchronization
               8.5.2.1 Computation of ToD phase difference
          8.5.3 ToD time synchronization
9 Physical media specific transmission convergence (PMS-TC) sub-layer
     9.1 Functional reference model
          9.1.1 δ reference point
          9.1.2 PMS-TC_MGMT interface
     9.2 DTU scrambler
     9.3 DTU encoder
     9.4 Interleaver
     9.5 Data frame multiplexer
     9.6 RMC
          9.6.1 RMC frame format
          9.6.2 RMC scrambler
          9.6.3 RMC encoder
          9.6.4 RMC message fields
     9.7 Acknowledgement
     9.8 Retransmission function
          9.8.1 Acknowledgement and retransmission latency requirements
          9.8.2 Retransmission control parameters
               9.8.2.1 Primary parameters
               9.8.2.2 Valid configurations
               9.8.2.3 Mandatory configurations
               9.8.2.4 Derived parameters
          9.8.3 Performance related parameters
               9.8.3.1 Definition of mean time between error events (MTBE)
                    9.8.3.1.1 Definition of MTBE_min
                    9.8.3.1.2 Accelerated testing of MTBE
               9.8.3.2 Definition of signal-to-noise ratio margin (SNRM)
                    9.8.3.2.1 Accelerated testing of SNRM
                    9.8.3.2.2 SNRM_MODE = 1
               9.8.3.3 Impulse noise protection
               9.8.3.4 Definition of signal-to-noise ratio margin for RMC (SNRM_RMC)
10 Physical media dependent (PMD) function
     10.1 PMD functional reference model
          10.1.1 U interface
          10.1.2 PMD_MGMT interface
               10.1.2.1 Vectoring interfaces
     10.2 Symbol encoder
          10.2.1  Data symbol encoder
               10.2.1.1 Bytes to bits padding
               10.2.1.2 Tone ordering
               10.2.1.3 Trellis coding
                    10.2.1.3.1 Bit extraction
                         10.2.1.3.1.1 Data symbols
                         10.2.1.3.1.2 RMC symbols
                    10.2.1.3.2 Bit conversion
                    10.2.1.3.3 Coset partitioning and trellis diagram (informative)
               10.2.1.4 Constellation mapper
                    10.2.1.4.1 Bit extraction
                    10.2.1.4.2 Constellations
                         10.2.1.4.2.1 Even values of b
                         10.2.1.4.2.2 Odd values of b
               10.2.1.5 Constellation point scaling
                    10.2.1.5.1 Power normalization
                    10.2.1.5.2 Gain adjuster
                    10.2.1.5.3 Frequency-domain transmit spectrum shaping (tssi)
                    10.2.1.5.4 Summary of the subcarrier constellation mapping and constellation point scaling
               10.2.1.6 Quiet symbol encoding
               10.2.1.7 Idle symbol encoding
          10.2.2 Symbol encoders for sync symbols, initialization symbols and pilot symbols
               10.2.2.1 Sync symbol encoder
               10.2.2.2 Initialization symbol encoder
                    10.2.2.2.1 Bit mapping of SOC symbols
                    10.2.2.2.2 Identification sequence (IDS) modulation
                    10.2.2.2.3 SOC symbol repetition
               10.2.2.3 Pilot symbol encoder
               10.2.2.4 Quadrant scrambler
                    10.2.2.4.1 Reset mode
                    10.2.2.4.2 Free-running mode
     10.3 Precoder (downstream vectoring)
          10.3.1 Overview
          10.3.2 Vectoring feedback channel
               10.3.2.1 Definition of normalized error sample
               10.3.2.2 Definition of DFT output samples
               10.3.2.3 Reporting of vectoring feedback (VF) samples
                    10.3.2.3.1 Control parameters for vectoring feedback reporting
                    10.3.2.3.2 Grouping of VF samples
                         10.3.2.3.2.1 Grouping of VF samples in case of error samples reporting
                         10.3.2.3.2.2 Grouping of VF samples in case of DFT output sample reporting
                         10.3.2.3.2.3 Calculation of N_block
               10.3.2.4 Vectoring feedback channel format
                    10.3.2.4.1 Format of the VFRB
                    10.3.2.4.2 Format of the VF block
                    10.3.2.4.3 Vectoring feedback channel data rate (informative)
               10.3.2.5 Identification of the VFRB
                    10.3.2.5.1 Frequency identification control parameters
                    10.3.2.5.2 Time identification control parameters
     10.4 Modulation
          10.4.1 Data subcarriers
          10.4.2 Subcarrier spacing
          10.4.3 Inverse discrete Fourier transform (IDFT)
          10.4.4 Cyclic extension and windowing
          10.4.5 Synchronization
               10.4.5.1 Pilot symbols
     10.5 TDD frame structure
          10.5.1 RMC symbol position
          10.5.2 Data symbol positions
     10.6 Superframe structure
     10.7 Normal and discontinuous operation intervals
     10.8 Alignment of transmissions in vectored group
11 Operation and maintenance (OAM)
     11.1 OAM functional model
          11.1.1 γ_MGMT interface
     11.2 Management functions and procedures over eoc
          11.2.1 eoc transmission method
               11.2.1.1 eoc packet format
               11.2.1.2 eoc message format
               11.2.1.3 eoc transmission protocol
          11.2.2 eoc commands and responses
               11.2.2.1 General
               11.2.2.2 Command and response types
               11.2.2.3  Segmentation of eoc messages
               11.2.2.4 Transparent eoc commands and responses
                    11.2.2.4.1 Clear eoc commands and responses
                    11.2.2.4.2 Datagram eoc command
               11.2.2.5 OLR commands and responses
               11.2.2.6 Diagnostic commands and responses
                    11.2.2.6.1 Perform self-test
                    11.2.2.6.2 Update test parameters
                    11.2.2.6.3 Start/end RTX_TESTMODE
                    11.2.2.6.4 Start/end TPS_TESTMODE
               11.2.2.7 NTR frequency synchronization command
               11.2.2.8 ToD frequency synchronization command
               11.2.2.9 Time synchronization command and responses
               11.2.2.10 Inventory commands and responses
               11.2.2.11 Management counter read commands and responses
               11.2.2.12 L3 link state transition commands and responses
                    11.2.2.12.1 L3 Request by FTU-R
                    11.2.2.12.2 L3 Request by FTU-O
               11.2.2.13 PMD test parameter read commands and responses
               11.2.2.14 Vectoring feedback command and responses
               11.2.2.15 Probe sequence update commands and responses
               11.2.2.16 L2 transition control
               11.2.2.17 DRR configuration commands and responses
               11.2.2.18  Fast startup training sequence parameters command and response
               11.2.2.19 Non-standard facility commands and responses
               11.2.2.20 INM facility commands and responses
               11.2.2.21 Update backup RTSBL
     11.3 OAM primitives
          11.3.1 Line-related primitives
               11.3.1.1 Near-end anomalies
               11.3.1.2 Far-end anomalies
               11.3.1.3 Near-end defects
               11.3.1.4 Far-end defects
               11.3.1.5 Initialization primitives
               11.3.1.6 Near-end OLR/FRA primitives
               11.3.1.7 Far-end OLR/FRA primitives
               11.3.1.8 Synchronous access network transient anomaly (SANTA)
          11.3.2 Path-related primitives
          11.3.3 Power-related primitives
               11.3.3.1 Near-end primitives
               11.3.3.2 Far-end primitives
          11.3.4 INM primitives
               11.3.4.1 Near-end primitives
               11.3.4.2 Far-end primitives
     11.4 OAM parameters
          11.4.1 Test and status parameters
               11.4.1.1 Status parameters
                    11.4.1.1.1 Net data rate (NDR)
                    11.4.1.1.2 Attainable net data rate (ATTNDR)
                    11.4.1.1.3 Expected throughput (ETR)
                    11.4.1.1.4 Attainable expected throughput (ATTETR)
                    11.4.1.1.5 Error-free throughput (EFTR) parameter
                    11.4.1.1.6 Minimum error-free throughput (EFTR_min) parameter
                    11.4.1.1.7 Actual INP against SHINE (INP_act_shine)
                    11.4.1.1.8 Actual INP against REIN (INP_act_rein)
                    11.4.1.1.9 Error-free bits counter
                    11.4.1.1.10 Signal-to-noise ratio margin parameter (SNRM)
                    11.4.1.1.11 Signal-to-noise ratio margin for the RMC (SNRM_RMC)
                    11.4.1.1.12 Net data rate in L2.1 (L2.1_NDR)
                    11.4.1.1.13 Net data rate in L2.2 (L2.2_NDR)
                    11.4.1.1.14 Expected throughput (L2.1_ETR)
                    11.4.1.1.15 Expected throughput (L2.2_ETR)
                    11.4.1.1.16 DTU FEC codeword size (NFEC)
                    11.4.1.1.17 DTU FEC redundancy (RFEC)
                    11.4.1.1.18 FEC codewords per DTU (Q)
                    11.4.1.1.19 Bit Allocation on data subcarriers (bi)
                    11.4.1.1.20 Bit Allocation on RMC subcarriers (bRMCi)
                    11.4.1.1.21 All NOI with Data symbols EFTR (ANDEFTR) parameter
                    11.4.1.1.22 Minimum All NOI with Data symbols EFTR (ANDEFTR_min) parameter
                    11.4.1.1.23 Maximum All NOI with Data symbols EFTR (ANDEFTR_max) parameter
                    11.4.1.1.24 Sum All NOI with Data symbols EFTR (ANDEFTR_sum) parameter
                    11.4.1.1.25 All NOI with Data symbols EFTR defined second (ANDEFTRDS)
               11.4.1.2 Test parameters
                    11.4.1.2.1 Hlog-psg
                    11.4.1.2.2 Signal-to-noise ratio per subcarrier (SNR-ps)
                    11.4.1.2.3 Quiet line noise PSD per subcarrier group (QLN-psg)
                    11.4.1.2.4 Active line noise PSD per subcarrier group (ALN-psg)
                    11.4.1.2.5 Actual transmit PSD reference per subcarrier (ACTPSDREF-ps)
                    11.4.1.2.6 Actual aggregate transmit power (ACTATP)
                    11.4.1.2.7 Signal attenuation (SATN)
                         11.4.1.2.7.1 Downstream signal attenuation (SATN_DS)
                         11.4.1.2.7.2 Upstream signal attenuation (SATN_US)
                    11.4.1.2.8 Actual transmit PSD per subcarrier (ACTPSDps)
                    11.4.1.2.9 FEXT downstream coupling coefficients (Xlogpsds)
                         11.4.1.2.9.1 Definition
                              11.4.1.2.9.1.1 FEXT coupling coefficient from line  into line
                              11.4.1.2.9.1.2 Direct channel insertion gain transfer function of line
                              11.4.1.2.9.1.3 FEXT insertion gain transfer function from line into line
                         11.4.1.2.9.2 Reporting of downstream FEXT coupling coefficients (Xlogpsds)
          11.4.2 Retransmission configuration parameters
               11.4.2.1 Minimum expected throughput (ETR_min)
               11.4.2.2 Maximum net data rate (NDR_max)
               11.4.2.3 Maximum delay (delay_max)
               11.4.2.4 Minimum impulse noise protection against SHINE (INP_min_shine)
               11.4.2.5 SHINEratio
               11.4.2.6 Minimum impulse noise protection against REIN (INP_min_rein)
               11.4.2.7 REIN Inter-arrival time for retransmission (iat_rein_flag)
               11.4.2.8 Minimum RFEC/NFEC ratio (rnratio_min)
          11.4.3 Vectoring configuration parameters
               11.4.3.1 FEXT cancellation enable/disable (FEXT_TO_CANCEL_ENABLE)
               11.4.3.2 Downstream requested Xlog subcarrier group size (XLOGGREQds)
               11.4.3.3 Downstream requested Xlog disturber line (XLOGDREQds)
          11.4.4 Line performance monitoring parameters
               11.4.4.1 Errored second (ES)
               11.4.4.2 Severely errored second (SES)
               11.4.4.3 Los second (LOSS)
               11.4.4.4 Lor second (LORS)
               11.4.4.5 Unavailable second (UAS)
               11.4.4.6 Inhibiting performance monitoring parameters
               11.4.4.7 Impulse noise monitoring facility procedure and parameters
                    11.4.4.7.1  INM procedure
                    11.4.4.7.2  INM configuration parameters
                         11.4.4.7.2.1 Definition of parameter INMIATO
                         11.4.4.7.2.2 Definition of parameter INMIATS
                         11.4.4.7.2.3 Definition of parameter INMCC
                         11.4.4.7.2.4 Definition of parameter INM_INPEQ_FORMAT
                         11.4.4.7.2.5 Definition of parameter BRGN
                         11.4.4.7.2.6 Definition of parameter INPEQ scaling factor (INPEQ_SF)
                         11.4.4.7.2.7 Definition of parameter IAT scaling factor (IAT_SF)
                    11.4.4.7.3 INM reporting parameters and primitives
                         11.4.4.7.3.1 INM INPEQ histogram primitives
                         11.4.4.7.3.2 INM total measurement count primitive
                         11.4.4.7.3.3 INM inter-arrival time histogram primitives
                         11.4.4.7.3.4 INM blank logical frame count primitive
               11.4.4.8 Low ANDEFTR second (LANDEFTRS)
          11.4.5 Low power link state parameters
          11.4.6 Inventory parameters
               11.4.6.1 Vectoring specific inventory parameters
                    11.4.6.1.1 VCE ID (VCE_ID)
                    11.4.6.1.2 VCE port index (VCE_port_index)
12 Link activation methods and procedures
     12.1 Overview
          12.1.1 Link states and link-state diagram
               12.1.1.1 Link-state diagram
               12.1.1.2 L3 – Idle state
               12.1.1.3 L0 – Normal operation state
               12.1.1.4 Low power link state L2.1
               12.1.1.5 Low power link state L2.2
               12.1.1.6 Transitions between link states
               12.1.1.7 Configuration and status reporting of the link state
                    12.1.1.7.1 Link state forced
                    12.1.1.7.2 Link state enabling
                    12.1.1.7.3 Link state status reporting
          12.1.2 Transceiver states and transceiver state diagram
          12.1.3 Initialization procedures
          12.1.4 Deactivation, reinitialization, persistent link defects and high_BER events
               12.1.4.1 Deactivation
               12.1.4.2 Fast retrain
               12.1.4.3 Persistent link defects and high_BER events
                    12.1.4.3.1 Persistent near-end los defect
                    12.1.4.3.2 Persistent near-end lom defect
                    12.1.4.3.3 Persistent near-end lor defect
                    12.1.4.3.4 High_BER event
     12.2 Special operations channel (SOC)
          12.2.1 Message format
               12.2.1.1 Byte stuffing
          12.2.2 Communication protocol
               12.2.2.1 Automatic repeat (AR) mode
               12.2.2.2 Repeat request (RQ) mode
               12.2.2.3 Non-repeat (NR) mode
          12.2.3 SOC IDLE (O-IDLE, R-IDLE)
          12.2.4 SOC messages
               12.2.4.1 Message codes
               12.2.4.2 O/R-REPEAT_REQUEST
               12.2.4.3 O/R-ACK-SEG
               12.2.4.4 FTU-O and FTU-R messages
               12.2.4.5  Mapping of SOC data
               12.2.4.6  Segmentation of SOC messages
     12.3 Initialization procedure
          12.3.1 Overview
          12.3.2 ITU-T G.994.1 handshake phase
               12.3.2.1 Handshake – FTU-O
                    12.3.2.1.1 CL messages
                    12.3.2.1.1.1 Short CL messages
                    12.3.2.1.2 MS messages
               12.3.2.2 Handshake – FTU-R
                    12.3.2.2.1 CLR messages
                         12.3.2.2.1.1 Short CLR messages
                    12.3.2.2.2 MS messages
          12.3.3 Channel discovery phase
               12.3.3.1 Overview
                    12.3.3.1.1 O-VECTOR 1 stage
                    12.3.3.1.2 CHANNEL DISCOVERY 1-1 stage
                    12.3.3.1.3 CHANNEL DISCOVERY 1 stage
                    12.3.3.1.4 R-VECTOR 1 stage
                    12.3.3.1.5 CHANNEL DISCOVERY 2 stage
                    12.3.3.1.6  R-VECTOR 1.1 stage
                    12.3.3.1.7  VECTOR 2 stage
                    12.3.3.1.8  PARAMETER UPDATE stage
               12.3.3.2 SOC messages transmitted during channel discovery phase
                    12.3.3.2.1  O-SIGNATURE
                    12.3.3.2.2  O-TG-UPDATE
                    12.3.3.2.3  R-MSG 1
                    12.3.3.2.4  O-UPDATE
                    12.3.3.2.5  R-UPDATE
                    12.3.3.2.6  O-VECTOR-FEEDBACK
                    12.3.3.2.7  R-ACK
                    12.3.3.2.8  R-VECTOR-FEEDBACK
                    12.3.3.2.9  O-SNR
                    12.3.3.2.10 R-SNR
                    12.3.3.2.11 O-PRM
                    12.3.3.2.12 R-PRM
               12.3.3.3 Signals transmitted during channel discovery phase
                    12.3.3.3.1 Signals during QUIET 1 stage
                         12.3.3.3.1.1 O-P-QUIET 1
                         12.3.3.3.1.2 R-P-QUIET 1
                    12.3.3.3.2  Signals during O-VECTOR 1 stage
                         12.3.3.3.2.1 O-P-VECTOR 1
                         12.3.3.3.2.2 R-P-QUIET 1
                    12.3.3.3.3  Signals during CHANNEL DISCOVERY 1-1 stage
                         12.3.3.3.3.1 O-P-CHANNEL-DISCOVERY 1-1
                         12.3.3.3.3.2 O-P-SYNCHRO 1-1
                         12.3.3.3.3.3 R-P-QUIET 1
                    12.3.3.3.4  Signals during CHANNEL DISCOVERY 1 stage
                         12.3.3.3.4.1 O-P-CHANNEL-DISCOVERY 1
                         12.3.3.3.4.2 R-P-VECTOR 1
                         12.3.3.3.4.3 O-P-SYNCHRO 1
                    12.3.3.3.5  Signals during CHANNEL DISCOVERY 2 stage
                         12.3.3.3.5.1 O-P-CHANNEL-DISCOVERY 2
                         12.3.3.3.5.2 R-P-CHANNEL-DISCOVERY 2
                         12.3.3.3.5.3 O-P-SYNCHRO 2
                    12.3.3.3.6  Signals during R-VECTOR 1.1 stage
                         12.3.3.3.6.1 O-P-VECTOR 1-1
                         12.3.3.3.6.2 R-P-VECTOR 1-1
                         12.3.3.3.6.3 O-P-SYNCHRO 3
                    12.3.3.3.7 Signals during VECTOR 2 stage
                         12.3.3.3.7.1 O-P-VECTOR 2
                         12.3.3.3.7.2 O-P-VECTOR 2-1
                         12.3.3.3.7.3 R-P-VECTOR 2
                         12.3.3.3.7.4 R-P-VECTOR 2-1
                         12.3.3.3.7.5 O-P-SYNCHRO 3-1
                         12.3.3.3.7.6 O-P-SYNCHRO 4
                    12.3.3.3.8  Signals during PARAMETER UPDATE stage
                         12.3.3.3.8.1 O-P-PRM-UPDATE 1
                         12.3.3.3.8.2 O-P-PRM-UPDATE 2
                         12.3.3.3.8.3 R-P-PRM-UPDATE 1
                         12.3.3.3.8.4 R-P-PRM-UPDATE 2
                         12.3.3.3.8.5 O-P-SYNCHRO 4-1
                         12.3.3.3.8.6 O-P-SYNCHRO 5
          12.3.4 Channel analysis and exchange phase
               12.3.4.1 Overview
               12.3.4.2 SOC messages exchanged during channel analysis and exchange phase
                    12.3.4.2.1 O-MSG 1
                    12.3.4.2.2 R-MSG 2
                    12.3.4.2.3 O-TPS
                    12.3.4.2.4 R-ACK 1
                    12.3.4.2.5 O-PMS
                    12.3.4.2.6 R-PMS
                    12.3.4.2.7 O-PMD
                    12.3.4.2.8 R-PMD
                    12.3.4.2.9 O-ACK
               12.3.4.3 Signals transmitted during the channel analysis and exchange phase
                    12.3.4.3.1 O-P-MEDLEY
                    12.3.4.3.2 O-P-SYNCHRO 6
                    12.3.4.3.3 R-P-MEDLEY
          12.3.5 Transition to showtime
               12.3.5.1 Establishment of DOI
          12.3.6 Alignment of initialization procedures of multiple joining lines (Informative)
               12.3.6.1 Joining group and waiting group (Informative)
               12.3.6.2 Alignment of the initialization procedures of multiple joining lines (Informative)
               12.3.6.3 Alignment of the parameters of multiple joining lines (Informative)
          12.3.7 Channel initialization policies
     12.4 Loop diagnostics mode
13 Online reconfiguration (OLR)
     13.1 Overview
          13.1.1 Types of online reconfiguration
          13.1.2 Types of bit-loading tables
          13.1.3 Summary of OLR types
     13.2 Eoc-based procedures
          13.2.1 Receiver initiated procedures
               13.2.1.1 SRA procedures
                    13.2.1.1.1 Parameters controlled by the SRA procedures
                         13.2.1.1.1.1 Parameters controlled by autonomous SRA in downstream
                         13.2.1.1.1.2 Parameters controlled by autonomous SRA in upstream
                    13.2.1.1.2 Parameters controlling the SRA procedures
                    13.2.1.1.3 SRA downshift procedure
                    13.2.1.1.4 SRA upshift procedure
                    13.2.1.1.5 Timing and synchronization for SRA
                    13.2.1.1.6 Retransmission of DTUs across SRA transitions
               13.2.1.2 Bit swapping procedure
                    13.2.1.2.1 Parameters controlled by bit swapping procedure
                    13.2.1.2.2 Bit swapping procedure
                    13.2.1.2.3 Timing and synchronization for bit swapping
               13.2.1.3 RPA procedure
                    13.2.1.3.1 Parameters controlling the RPA procedures
                    13.2.1.3.2 Parameters controlled by the RPA procedure
                    13.2.1.3.3 Timing and synchronization for RPA
               13.2.1.4 L2TSA procedure
                    13.2.1.4.1 Parameters controlling the L2TSA procedures
                    13.2.1.4.2 Parameters controlled by the L2TSA procedure
                    13.2.1.4.3 Timing and synchronization for L2TSA
          13.2.2 Transmitter initiated procedures
               13.2.2.1 TIGA procedure
                    13.2.2.1.1 Parameters controlled by the TIGA procedure
                         13.2.2.1.1.1 Parameters controlled by the TIGA request
                         13.2.2.1.1.2 Parameters controlled by the TIGA response
                    13.2.2.1.2 Timing and synchronization for TIGA
     13.3 RMC-based procedures
          13.3.1 Receiver initiated procedures
               13.3.1.1 FRA procedure
                    13.3.1.1.1 Parameters controlling the FRA procedure
                         13.3.1.1.1.1 FRA time window (fra-time)
                         13.3.1.1.1.2 Minimum percentage of degraded tones (fra-ntones)
                         13.3.1.1.1.3 Minimum number of rtx-uc anomalies (fra-rtx-uc)
                         13.3.1.1.1.4 Vendor discretionary criteria (fra-vendisc)
                         13.3.1.1.1.5 FRA triggering criteria
                    13.3.1.1.2 Parameters controlled by the FRA procedure
                    13.3.1.1.3 Timing and synchronization for receiver initiated FRA
                    13.3.1.1.4 Aligning FRA with SRA and L2-TRNS
               13.3.1.2 RMCR procedure
                    13.3.1.2.1 RMCR triggering criteria
                    13.3.1.2.2 RMCR recovery criteria
                    13.3.1.2.3 Parameters controlling the RMCR procedure
                    13.3.1.2.4 Parameters controlled by the RMCR procedure
                    13.3.1.2.5 Timing and synchronization of RMCR
          13.3.2 Transmitter initiated procedures
               13.3.2.1 FRA procedures
     13.4 Low power link states
          13.4.1 Low power link state L2.1
               13.4.1.1 L2.1 transmission format
               13.4.1.2 L2.1 entry procedure
                    13.4.1.2.1 L2.1 entry policy
               13.4.1.3 Operation during L2.1
                    13.4.1.3.1 L2.1 operation policy
                    13.4.1.3.2 L2.1 operation procedures
               13.4.1.4 L2.1 exit procedure
                    13.4.1.4.1 Procedures at exit of L2.1
                    13.4.1.4.2 L2.1 exit policy
                    13.4.1.4.3 Procedures after entry into L0
                    13.4.1.4.4 Aligning L2.1 exit and TIGA
               13.4.1.5 L2.1 control parameters
                    13.4.1.5.1 Minimum expected throughput in L2.1 (L2.1_ETR_min)
                    13.4.1.5.2 Maximum Net Data Rate in L2.1 (L2.1_NDR_max)
                    13.4.1.5.3 Target SNR margin in L2 (L2_TARSNRM)
                    13.4.1.5.4  Maximum SNR margin in L2.1 (L2.1_MAXSNRM)
                    13.4.1.5.5 Maximum PSD reduction in L2 (L2_PSDR_max)
                    13.4.1.5.6 Minimum expected ETR upon returning from the L2.1 link state to the L0 link state (L2.1_Exit_ETR_min)
                    13.4.1.5.7 Rate adaptation upshift & downshift SNR margin (L2.1_RA_USNRM & L2.1_RA_DSNRM)
                    13.4.1.5.8 Expected ETR upon returning from the L2.1 link state to the L0 link state (L2.1_Exit_ETR)
          13.4.2 Low power link state L2.2
               13.4.2.1 L2.2 transmission format
               13.4.2.2 L2.2 Entry procedure
                    13.4.2.2.1 L2.2 entry policy
               13.4.2.3 Operation during L2.2
                    13.4.2.3.1 L2.2 operation policy
                    13.4.2.3.2 L2.2 operation procedures
               13.4.2.4 L2.2 Exit procedure
                    13.4.2.4.1 Procedures at exit of L2.2
                    13.4.2.4.2 L2.2 exit policy
               13.4.2.5 L2.2 control parameters
                    13.4.2.5.1 Minimum expected throughput in L2.2 (L2.2_ETR_min)
                    13.4.2.5.2 Maximum Net Data Rate in L2.2 (L2.2_NDR_max)
          13.4.3 Transition between L2.1N and L2.1B
          13.4.4 Low power link state control parameters
               13.4.4.1 Primary control parameters
               13.4.4.2 Derived framing parameters
14 Electrical requirements
     14.1 Balance
          14.1.1 Longitudinal conversion loss
          14.1.2 Common mode port impedance
     14.2 Differential port impedance
Annex A to Annex C
Annex D  Operation with Dynamic Time Assignment in a crosstalk environment
     D.1 Scope
     D.2 Definitions
     D.3 Abbreviations and acronyms
     D.4 Reference model(s)
     D.5 Coordinated Dynamic time assignment (cDTA)
          D.5.1 cDTA-related primitives at the γO reference point
          D.5.2 The cDTA procedure
          D.5.3 Valid values of Mds for cDTA
          D.5.4 The TDD frame prior to and after a cDTA update
               D.5.4.1 Performance during transitions
          D.5.5 Superframe structure for cDTA
          D.5.6 Timing and synchronization for cDTA
               D.5.6.1 One-step procedure
               D.5.6.2 Two-step procedure
               D.5.6.3 General requirements to increase robustness
               D.5.6.4 Logical frame parameter in cDTA
                    D.5.6.4.1 RMC content during one step procedure
                    D.5.6.4.2 RMC content during two step procedure
          D.5.7 Transceiver related cDTA control parameters
               D.5.7.1 Annex D operation mode (Annex_D_mode)
               D.5.7.2 cDTA allowed (cDTA_allowed)
               D.5.7.3 Minimum Mds for DTA (DTA_min_Mds)
               D.5.7.4 Maximum Mds for DTA (DTA_max_Mds)
               D.5.7.5 Maximum net data rate for DTA (DTA_NDR_max)
               D.5.7.6 Maximum net data rate (NDR_max)
               D.5.7.7 Minimum expected throughput (ETR_min)
          D.5.8 Transceiver related DTA status parameters
               D.5.8.1 Annex D operation enabled (Annex_D_enabled)
               D.5.8.2 cDTA procedure actual type (cDTA_proc_act)
               D.5.8.3 Data rate reporting if cDTA is enabled
                    D.5.8.3.1 Net data rate (NDR)
                    D.5.8.3.2 Attainable net data rate (ATTNDR)
                    D.5.8.3.3 Expected throughput (ETR)
                    D.5.8.3.4 Attainable expected throughput (ATTETR)
               D.5.8.4 Minimum Mds supported by the FTU-R (FTUR_DTA_min_Mds)
          D.5.9 Channel initialization policy for cDTA
          D.5.10 High_BER event for cDTA
          D.5.11 RMC commands
          D.5.12 eoc commands
               D.5.12.1 Update 'min used initial DTAFDC'
     D.6 Initialization messages
          D.6.1 ITU-T G.994.1 Handshake phase
               D.6.1.1 Handshake – FTU-O
                    D.6.1.1.1 CL messages
                    D.6.1.1.2 MS messages
               D.6.1.2 Handshake – FTU-R
                    D.6.1.2.1 CLR messages
                    D.6.1.2.2 MS messages
          D.6.2 Channel analysis and exchange phase
               D.6.2.1 O-PMS
               D.6.2.2 R-MSG 2
               D.6.2.3 O-MSG 1
Annex E to Annex Q
Annex R  Showtime reconfiguration
     R.1 Scope
     R.2 Overview
          R.2.1 Reconfiguration of the line
     R.3 Showtime reconfiguration procedures
          R.3.1 Local showtime reconfiguration (SREC-L) procedure
          R.3.2 Remote showtime reconfiguration procedure
          R.3.3 Transition time period
     R.4 Management of the showtime reconfiguration protocol
     R.5 Showtime reconfiguration request eoc commands
     R.6 Near-end anomalies
Annex S  NT software upgrade
     S.1 Scope
     S.2 References
     S.3 Reference model
     S.4 Software image management process
          S.4.1 Fundamental usage
               S.4.1.1 Software images attributes for fundamental usage
               S.4.1.2 Actions supporting the software upgrade process
          S.4.2 Vendor-specific usage
               S.4.2.1 File attributes for the vendor-specific usage
               S.4.2.2 Actions for vendor-specific usage and download process
          S.4.3 OAM data for software management
               S.4.3.1 Transaction correlation identifier
               S.4.3.2 Message type field
               S.4.3.3 Get software image and get software image response messages
     S.5 Message set
          S.5.1 Get software image
          S.5.2 Get software image response
          S.5.3 Start software download
          S.5.4 Start software download response
          S.5.5 Download section
          S.5.6 Download section response
          S.5.7 End software download
          S.5.8 End software download response
          S.5.9 Activate image
          S.5.10 Activate image response
          S.5.11 Commit image
          S.5.12 Commit image response
     S.6 Software upgrade (informative)
          S.6.1 Overview
          S.6.2 Software image download
          S.6.3 Software image activate and commit
Annex T  Dynamic time assignment (DTA) – higher-layer control aspects
     T.1 Scope
     T.2 DTA control parameters
          T.2.1 Annex X operation mode (Annex_X_mode)
          T.2.2 Annex D operation mode (Annex_D_mode)
          T.2.3 iDTA allowed according to Annex X (iDTA_allowed)
          T.2.4 cDTA allowed according to Annex D (cDTA_allowed)
          T.2.5 Handshake Mds (hs_Mds)
          T.2.6 Preferred Mds for DTA (DTA_pref_Mds)
          T.2.7 Maximum step size for DTA changes (DTA_SMax)
          T.2.8 Minimum Mds for DTA (DTA_min_Mds)
          T.2.9 Maximum Mds for DTA (DTA_max_Mds)
          T.2.10 Minimum expected throughput for DTA (DTA_ETR_min)
          T.2.11 Maximum net data rate for DTA (DTA_NDR_max)
          T.2.12 cDTA procedure control (cDTA_proc_ctrl)
          T.2.13 Minimum time between DTA updates (DTA_Min_Time)
     T.3 Coordination between the link state request and the DTA request
Annex U
Annex V  Targeted generalized vectoring with non-active ITU-T G.9701  supporting lines (TGVN)
     V.1 Scope
     V.2 Definitions
     V.3 Downstream TGVN (TGVNds)
          V.3.1 Functional model for downstream
          V.3.2 Implementing TGVNds (informative)
               V.3.2.1 Initialization
               V.3.2.1.1 Lines with a non-active ITU-T G.9701 session
               V.3.2.1.2 Lines with an active ITU-T G.9701 session
               V.3.2.2 Showtime
               V.3.2.2.1 Lines with a non-active ITU-T G.9701 session
               V.3.2.2.2 Lines with an active ITU-T G.9701 session
     V.4 Upstream TGVN (TGVNus)
          V.4.1 Functional model for upstream (informative)
          V.4.2 Implementing TGVNus (informative)
               V.4.2.1 Lines with a non-active ITU-T G.9701 session
               V.4.2.2 Lines with an active ITU-T G.9701 session
     V.5 Transceiver states and transceiver state diagram (amend clause 12.1.2)
     V.6 Management of TGVN
          V.6.1 TGVN configuration parameters
          V.6.2 TGVN test parameters
               V.6.2.1 Quiet line noise PSD per subcarrier group (QLN-psg) (amends clause 11.4.1.2.3)
               V.6.2.2 Actual transmit PSD per subcarrier (ACTPSDps) (amends clause 11.4.1.2.8)
               V.6.2.3 Actual aggregate transmit power (ACTATP) (amends clause 11.4.1.2.6)
          V.6.3 Inventory parameters
Annex W
Annex X  Operation without multi-line coordination intended  for a crosstalk-free environment
     X.1 Scope
     X.2 Definitions
     X.3 Abbreviations and acronyms
     X.4 Reference model(s)
     X.5 Profiles
          X.5.1 Annex X profiles 106c and 212c for operation over coaxial cables in a crosstalk-free environment
          X.5.2 Profiles for operation over twisted-pair cables in a crosstalk-free environment
          X.5.3 Profile compliance
     X.6 Independent dynamic time assignment (iDTA)
          X.6.1 iDTA-related primitives at the γO reference point
          X.6.2 The iDTA procedure
          X.6.3 Valid values of Mds for DTA
          X.6.4 The TDD frame prior to and after an iDTA update
               X.6.4.1 Performance during transitions
          X.6.5 Superframe structure for iDTA
          X.6.6 Timing and synchronization for iDTA
          X.6.7 Transceiver related iDTA control parameters
               X.6.7.1 Annex X operation mode (Annex_X_mode)
               X.6.7.2 iDTA allowed (iDTA_allowed)
               X.6.7.3 Minimum Mds for DTA (DTA_min_Mds)
               X.6.7.4 Maximum Mds for DTA (DTA_max_Mds)
               X.6.7.5 Maximum net data rate for DTA (DTA_NDR_max)
               X.6.7.6 Maximum net data rate (NDR_max)
               X.6.7.7 Minimum expected throughput (ETR_min)
          X.6.8 Transceiver related iDTA status parameters
               X.6.8.1 Annex X operation enabled (Annex_X_enabled)
               X.6.8.2 iDTA enabled (iDTA_enabled)
               X.6.8.3 Data rate reporting if iDTA is enabled
                    X.6.8.3.1 Net data rate (NDR)
                    X.6.8.3.2 Attainable net data rate (ATTNDR)
                    X.6.8.3.3 Expected throughput (ETR)
                    X.6.8.3.4 Attainable expected throughput (ATTETR)
          X.6.9 Channel initialization policy for iDTA
          X.6.10 High_BER event for iDTA
          X.6.11 RMC commands
     X.7 Initialization messages
          X.7.1 ITU-T G.994.1 Handshake phase
               X.7.1.1 Handshake – FTU-O
                    X.7.1.1.1 CL messages
                    X.7.1.1.2 MS messages
               X.7.1.2 Handshake – FTU-R
                    X.7.1.2.1 CLR messages
                    X.7.1.2.2 MS messages
          X.7.2 Channel analysis and exchange phase
               X.7.2.1 O-MSG 1
               X.7.2.2 R-MSG 2
     X.8 Discontinuous operation
     X.9 On-line reconfiguration
     X.10  Initialization
     X.11 Low power states
     X.12 Adaptation to the coaxial cable medium
          X.12.1 Application reference model
          X.12.2 Termination impedance
          X.12.3 Maximum aggregate transmit power
          X.12.4 MDU coaxial cable configurations (informative)
Annex Y   Upstream dynamic resource reports
Annex Z   Cross-layer traffic monitoring functions and link state control
     Z.0 Introduction
     Z.1 Definition of Terms
     Z.2 Abbreviations and acronyms
     Z.3 Reference models
     Z.4 Generic traffic monitoring functions
          Z.4.1 Traffic monitor function (TMF)
          Z.4.2 DRRUSF
     Z.5 Generic information flows
          Z.5.1 Data flows
               Z.5.1.1 The ( reference point
          Z.5.2 Control Flows
               Z.5.2.1 The O reference point
               Z.5.2.2 The R reference point
               Z.5.2.3 The (O reference point
               Z.5.2.4 The (R reference point
               Z.5.2.5 The γR reference point
     Z.6 Link state specific functions
          Z.6.1 LRCC-O function
          Z.6.2 Triggers for link state change – Principles of operation
               Z.6.2.1 Input information
               Z.6.2.2 Traffic information processing
                    Z.6.2.2.1 Queue arrival processing
                    Z.6.2.2.2 Queue fill processing
               Z.6.2.3 Trigger criteria – principles of operation
                    Z.6.2.3.1 Traffic-driven link state transitions
                    Z.6.2.3.2 Battery operation status driven link state transitions
     Z.7 Link state management and reporting parameters
Appendix I  Wiring topologies and reference loops
     I.1 Wiring topologies
Figure I.1 – Modified star wiring topology
Figure I.2 – Distributed wiring topology
     I.2 Reference loops
          I.2.1 The final drop
Figure I.3 – Overview of the final drop
Figure I.4 – Primary final drop loop (D5)
Figure I.5 – Illustration of final drop loops
     I.2.2 In-premises wiring
Figure I.6 – Overview of the in-premises wiring
Figure I.7 – Illustration of in-premises loops
     I.2.3 Reference combinations
Table I.3 – Reference combinations
     I.2.4 Wire types
Table I.4 – Wire types
     I.2.4.1 Cable model for wiring types B05a (CAD55), CAT5, T05u, T05b and T05h
Appendix II  Example OLR use cases
     II.1 Transmitter initiated gain adjustment (TIGA)
          II.1.1 Flow chart
Appendix III  Motivation of MTBE accelerated test
Appendix IV  Targeted generalized vectoring with active ITU-T G.9701  supporting lines (TGVA)
     IV.1 Scope
     IV.2 Definitions
     IV.3 Downstream TGVA (TGVAds)
          IV.3.1 Functional model for downstream
          IV.3.2 Implementing TGVAds
               IV.3.2.1 Initialization
               IV.3.2.2 Showtime
     IV.4 Upstream TGVA (TGVAus)
          IV.4.1 Functional model for upstream
          IV.4.2 Implementing TGVAus
Appendix V  Retransmission buffer size and the achievable bit-rate
     V.1 Case 1: NSYMret+NSYMack+1 ≤ Mus
     V.2 Case 2: NSYMret+NSYMack+1≥Mus
     V.3 Case 3: Lower bound for the achievable net data rate
     V.4 Memory size example
Appendix VI  Example applications of discontinuous operation
     VI.1 Discontinuous operation with vectoring disabled
     VI.2 Examples of discontinuous operation with vectoring enabled
Appendix VII   Calculation of loop attenuation (LATN)
Appendix VIII   Impulse noise monitoring – detection and interpretation of impulse noise using clusters of corrupted DTUs
     VIII.1 Overview
     VIII.2 Expected accuracy of impulse noise events
          VIII.2.1 Case of small DTUs
          VIII.2.2 Case of large DTUs
Appendix IX  Examples of the cDTA procedure
     IX.1 Mds is increased
     IX.1.1 Example 1
     IX.1.2 Example 2
     IX.2 Mds is decreased
     IX.2.1 Example 1
     IX.2.2 Example 2
Appendix X  Configuration Parameters Describing Preferred Net Data Rate
     X.1 Scope
     X.2 Definitions
     X.3 Abbreviations and acronyms
     X.4 Preferred net data rate parameters
Bibliography