CONTENTS

 1     Scope
 2     References
 3     Definitions and abbreviations
        3.1     Definitions
        3.2     Abbreviations
 4     Reference models
        4.1     System reference model
        4.2     ATU reference model
 5     Transport capacity
 6     ATU interfaces
        6.1     ATU interface for ATM transport
        6.2     ATU PMD to TC logical interface
 7     ATU functional characteristics
        7.1     ATM transport protocol specific functionalities
                  7.1.1     Payload transfer delay
                  7.1.2     ATM cell specific functionality
                  7.1.3     Framing structure for ATM transport
        7.2     Network Timing Reference
                  7.2.1     Optional NTR capability
                  7.2.2     Transport of the NTR
        7.3     Framing
                  7.3.1     Relationship to G.992.1 framing
                  7.3.2     Bit ordering
                  7.3.3     Data framing and reference points
        7.4     Scrambler
        7.5     Reed-Solomon Forward Error Correction
                  7.5.1     Reed-Solomon coding
                  7.5.2     Reed-Solomon Forward Error Correction superframe synchronization
        7.6     Interleaver
        7.7     Tone ordering
        7.8     Constellation encoder
                  7.8.1     Bit extraction
                  7.8.2     Constellation encoder
        7.9     Gain scaling
       7.10     Modulation
                 7.10.1     Subcarriers
                 7.10.2     Modulation by the inverse discrete Fourier transform (IDFT)
                 7.10.3     Synchronization symbol
                 7.10.4     Upstream data pattern
                 7.10.5     Downstream data pattern
       7.11     Cyclic prefix
       7.12     Transmitter dynamic range
                 7.12.1     Maximum clipping rate
                 7.12.2     Noise/Distortion floor
                 7.12.3     Transmitter spectral masks
 8     Embedded Operations Channel (eoc)
        8.1     eoc introduction
                  8.1.1     eoc messages overview
                  8.1.2     eoc protocol overview
        8.2     eoc message encoding
                  8.2.1     ADDRESS field (# 1)
                  8.2.2     Data or opcode field (# 2)
                  8.2.3     BYTE PARITY field (# 3)
                  8.2.4     AUTONOMOUS MESSAGE field (# 4)
                  8.2.5     INFORMATION field (# 5)
        8.3     eoc message description
                  8.3.1     Latching bidirectional eoc messages
                  8.3.2     End of Data message (EOD)
                  8.3.3     Dying Gasp message (DGASP)
                  8.3.4     Autonomous messages
                  8.3.5     Data registers in the ATU‑R
        8.4     eoc protocol
                  8.4.1     Outstanding eoc messages
                  8.4.2     eoc state transitions
        8.5     Clear eoc
 9     ADSL overhead channel
        9.1     The ADSL Overhead Control (aoc) channel introduction
                  9.1.1     Bit swap channel
                  9.1.2     Superframe counting
        9.2     aoc message encoding
                  9.2.1     aoc message header encoding
                  9.2.2     Profile Management Request
                  9.2.3     Profile Management Acknowledge
                  9.2.4     Bit swap request message encoding
                  9.2.5     Extended bit swap request message encoding
                  9.2.6     Bit swap acknowledge message encoding
        9.3     Bit swap operation
                  9.3.1     Bit swap – Receiver
                  9.3.2     Bit swap – Transmitter
        9.4     aoc protocol
10     In-service performance monitoring and surveillance
       10.1     ADSL line related primitives
                 10.1.1     ADSL line related near-end anomalies
                 10.1.2     ADSL line related far‑end anomalies
                 10.1.3     ADSL line related near‑end defects
                 10.1.4     ADSL line related far-end defects
       10.2     ATM data path related primitives
                 10.2.1     ATM data path related near‑end anomalies
                 10.2.2     ATM data path related far‑end anomalies
                 10.2.3     ATM data path related near‑end defects
                 10.2.4     ATM data path related far‑end defects
       10.3     Other ADSL indicators, parameters and signals
                 10.3.1     Other near‑end primitives
                 10.3.2     Other far‑end primitives
                 10.3.3     Failure count parameters
       10.4     Test parameters
                 10.4.1     Near‑end test parameters
                 10.4.2     Far‑end test parameters
       10.5     Other failures and parameters
11     Initialization
       11.1     Overview
                 11.1.1     Basic functions of initialization
                 11.1.2     Transparency to methods of separating upstream and downstream signals
                 11.1.3     Initialization Reset Procedure
       11.2     Handshake – ATU‑C
       11.3     Handshake – ATU‑R
       11.4     Handshake power levels
       11.5     Escape from Handshake to Fast Retrain
                 11.5.1     C‑QUIET-EF1
                 11.5.2     R‑QUIET-EF1
       11.6     Power levels in Transceiver Training, Channel Analysis and Exchange
       11.7     Transceiver training – ATU‑C
                 11.7.1     C‑QUIET2
                 11.7.2     C‑PILOT1
                 11.7.3     C‑PILOT1A
                 11.7.4     C‑QUIET3A
                 11.7.5     C‑REVERB1
                 11.7.6     C‑PILOT2
                 11.7.7     C‑ECT
                 11.7.8     C‑REVERB2
                 11.7.9     C‑QUIET5
                11.7.10     C‑PILOT3
                11.7.11     C‑REVERB3
       11.8     Transceiver training – ATU‑R
                 11.8.1     R‑QUIET2
                 11.8.2     R‑REVERB1
                 11.8.3     R‑QUIET3
                 11.8.4     R‑ECT
                 11.8.5     R‑REVERB2
       11.9     Channel analysis (ATU‑C)
                 11.9.1     C‑SEGUE1
                 11.9.2     C‑RATES1
                 11.9.3     C‑CRC1
                 11.9.4     C-MSG1
                 11.9.5     C‑CRC2
                 11.9.6     C‑MEDLEY
      11.10     Channel analysis (ATU‑R)
                11.10.1     R-SEGUE1
                11.10.2     R‑REVERB3
                11.10.3     R‑SEGUE2
                11.10.4     R‑RATES1
                11.10.5     R‑CRC1
                11.10.6     R-MSG1
                11.10.7     R‑CRC2
                11.10.8     R‑MEDLEY
                11.10.9     R‑REVERB4
      11.11     Exchange – ATU‑C
                11.11.1     C‑REVERB4
                11.11.2     C‑SEGUE2
                11.11.3     C-RATES-RA
                11.11.4     C-CRC-RA1
                11.11.5     C-MSG-RA
                11.11.6     C-CRC-RA2
                11.11.7     C-REVERB-RA
                11.11.8     C-SEGUE-RA
                11.11.9     C-MSG2
               11.11.10     C‑CRC3
               11.11.11     C‑RATES2
               11.11.12     C‑CRC4
               11.11.13     C‑B&G
               11.11.14     C‑CRC5
               11.11.15     C‑REVERB5
               11.11.16     C‑SEGUE3
      11.12     Exchange – ATU‑R
                11.12.1     R‑SEGUE3
                11.12.2     R-MSG-RA
                11.12.3     R-CRC-RA1
                11.12.4     R-RATES-RA
                11.12.5     R-CRC-RA2
                11.12.6     R-REVERB-RA
                11.12.7     R-SEGUE-RA
                11.12.8     R-MSG2
                11.12.9     R‑CRC3
               11.12.10     R‑RATES2
               11.12.11     R‑CRC4
               11.12.12     R‑REVERB5
               11.12.13     R‑SEGUE4
               11.12.14     R‑B&G
               11.12.15     R‑CRC5
               11.12.16     R‑REVERB6
               11.12.17     R‑SEGUE5
      11.13     Details of initialization timing
12     Fast Retrain
       12.1     Fast Retrain overview
                 12.1.1     Profile requirements
       12.2     Definition of Fast Retrain signals
                 12.2.1     Fast Retrain Signal power levels
       12.3     Fast Retrain Procedure
                 12.3.1     ATU‑C initiated from SHOWTIME
                 12.3.2     ATU‑R initiated from SHOWTIME
                 12.3.3     Channel measurement
                 12.3.4     Selection of Tx power levels
                 12.3.5     Transceiver retraining
                 12.3.6     Profile exchange
       12.4     Fast Retrain Procedure – Unknown Profile Transition
       12.5     Fast Retrain Procedure – Initiated from L3 or Recommendation G.994.1
       12.6     Abort of Fast Retrain
                 12.6.1     Abort of an ATU‑C initiated Fast Retrain Request
                 12.6.2     Abort of an ATU‑R initiated Fast Retrain Request
       12.7     Fast Retrain Truncate
       12.8     Fast Retrain Reset Procedure
13     Power management
       13.1     Introduction
       13.2     ADSL link states
       13.3     Link state transitions
       13.4     Link transition procedures
                 13.4.1     Transitions from L0 to L0 (T0a, T0b, T0c)
                 13.4.2     Transition from L0 to L1 (T0d)
                 13.4.3     Transitions from L1 to L0 (T1a, T1b, T1c, T1d)
                 13.4.4     Transitions from L0 or L1 to L3 (T0e, T0f, T1e, T1f)
                 13.4.5     Transitions from L3 to L0 (T3a, T3b)
       13.5     eoc Handshake
                 13.5.1     ATU‑R initiated eoc Handshake
                 13.5.2     ATU‑C initiated eoc Handshake
Annex A – Non-overlapped spectrum operation
        A.1     ATU‑R transmitter PSD mask
                  A.1.1     Passband PSD ripple and group delay
                  A.1.2     Transmit power spectral density and aggregate power level
        A.2     ATU‑C transmitter PSD mask
                  A.2.1     Passband PSD ripple and group delay
                  A.2.2     Transmit power spectral density and aggregate power level
Annex B – Overlapped spectrum operation
        B.1     ATU-R transmitter PSD mask
                  B.1.1     Passband PSD ripple and group delay
                  B.1.2     Transmit power spectral density and aggregate power level
        B.2     ATU‑C transmitter PSD mask
                  B.2.1     Passband PSD ripple and group delay
                  B.2.2     Transmit power spectral density and aggregate power level
Annex C – ADSL above POTS co-existing in the same binder as TCM-ISDN DSL
        C.1     Scope
        C.2     Definitions and abbreviations
                  C.2.1     Definitions
                  C.2.2     Abbreviations
        C.3     Reference models
                  C.3.1     ATU‑C transmitter reference model (replaces figure in 4.2)
                  C.3.2     ATU‑R transmitter reference model (replaces figure in 4.2)
                  C.3.3    ATU transmitter timing model (new)
        C.4     ATU interfaces
                  C.4.1     ATM interface for ATM transport (replaces figure in 6.1)
        C.5     ATU functional characteristics (pertains to clause 7)
                  C.5.1     Payload transfer delay (supplements 7.1.1)
                  C.5.2     Framing (pertains to 7.3)
                  C.5.3     Modulation (pertains to 7.10)
                  C.5.4     Transmitter spectral mask (replaces 7.12.3)
                  C.5.5     Dual Bitmap (new)
                  C.5.6     Rate Converter (new)
                  C.5.7     FEXT Bitmap (new)
        C.6     aoc on-line adaptation and reconfiguration (pertains to clause 9)
                  C.6.1     Bit swap request message encoding (replaces 9.2.4)
                  C.6.2     Extended bit swap request message encoding (supplements 9.2.5)
                  C.6.3     Bit swap acknowledge message encoding (supplements 9.2.6)
        C.7     In-service performance monitoring and surveillance (pertains to clause 10)
                  C.7.1     ADSL line related primitives (pertains to 10.1)
                  C.7.2     Test parameters (supplements 10.4)
        C.8     Initialization
                  C.8.1     Initialization with Hyperframe (new)
                  C.8.2     Escape from Handshake to Fast Retrain (replaces 11.5)
                  C.8.3     Transceiver training – ATU‑C (supplements 11.7)
                  C.8.4     Transceiver training – ATU‑R (supplements 11.8)
                  C.8.5     Channel analysis (ATU‑C) (supplements 11.9)
                  C.8.6     Channel analysis (ATU‑R) (supplements 11.10)
                  C.8.7     Exchange – ATU‑C (supplements 11.11)
                  C.8.8     Exchange – ATU‑R (supplements 11.12)
        C.9     Fast retraining (supplements clause 12)
                  C.9.1     Fast Retrain overview (pertains to 12.1)
                  C.9.2     Definition of Fast Retrain signals (supplements 12.2)
                  C.9.3     Fast Retrain procedure (supplements 12.3)
                  C.9.4     Initiated from L3 or Recommendation G.994.1 (replaces 12.5)
       C.10     Power management (pertains to clause 13)
                 C.10.1     Transition from L0 to L1 (T0d) (pertains to 13.4.2)
Annex D – System performance for North America
        D.1     System performance for North America
                  D.1.1     Required test cases
                  D.1.2     Extended reach cases
Annex E – System performance for Europe
        E.1     System performance for Europe
Appendix I
Appendix II – Guide to scenarios for the implementation of the various procedures in Recommendations G.994.1 and G.992.2
Appendix III – Compatibility with other Customer Premises Equipment