ANSI T1.413-1995
`
`for Telecommunications -
`Network and Customer
`A Installation Interfaces —
`. Asymmetric Digital Subscriber
`Line (ADSL) Metallic Interface‘
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`W’ American National Standards Institute
`11 West 42nd Street
`
`New York, New York
`10036
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`

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`

`
`ANSI
`T1.413-1995
`
`®
`
`American National Standard
`for Telecommunications –
`
`Network and Customer Installation Interfaces –
`Asymmetric Digital Subscriber Line (ADSL) Metallic Interface
`
`Secretariat
`Alliance for Telecommunications Industry Solutions
`
`Approved August 18, 1995
`American National Standards Institute, Inc.
`
`Abstract
`This standard presents the electrical characteristics of the Asymmetric Digital Subscriber Line
`(ADSL) signals appearing at the network interface. The physical interface between the network
`and the customer installation is also described. The transport medium for the signals is a single
`twisted-wire pair that supports both Message Telecommunications Service (POTS) and full-duplex
`(simultaneous two-way) and simplex (from the network to the customer installation) digital ser -
`vices.
`
`This interface standard provides the minimal set of requirements for satisfactory transmission
`between the network and the customer installation. Equipment may be implemented with addition-
`al functions and procedures.
`
`

`
`American
`National
`Standard
`
`Approval of an American National Standard requires verification by ANSI
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`
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`
`CAUTION NOTICE: This American National Standard may be revised or
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`
`Published by
`
`American National Standards Institute
`11 West 42nd Street, New York, New York 10036
`
`Copyright ©1995 by Alliance for Telecommunications Industry Solutions
`All rights reserved.
`
`No part of this publication may be reproduced in any
`form, in an electronic retrieval system or otherwise,
`without prior written permission of the publisher.
`
`Printed in the United States of America
`
`INSERT CODE
`
`

`
`Contents
`
`Page
`Foreword .............................................................................................................vii
`
`1
`
`1.1
`1.2
`
`2
`
`3
`
`3.1
`3.2
`
`4
`
`4.1
`4.2
`4.3
`
`5
`
`5.1
`5.2
`5.3
`5.4
`5.5
`
`6
`
`6.1
`6.2
`6.3
`6.4
`6.5
`6.6
`6.7
`6.8
`6.9
`6.10
`6.11
`6.12
`6.13
`
`7
`
`7.1
`7.2
`7.3
`7.4
`7.5
`7.6
`7.7
`7.8
`7.9
`7.10
`7.11
`7.12
`7.13
`
`Scope and purpose ................................................................................1
`
`Scope .....................................................................................................1
`Purpose ..................................................................................................1
`
`Normative references .............................................................................2
`
`Definitions, abbreviations, acronyms and symbols.................................3
`
`Definitions...............................................................................................3
`Abbreviations, acronyms and symbols ...................................................3
`
`Reference models ..................................................................................6
`
`System reference model.........................................................................6
`ATU-C transmitter reference model........................................................7
`ATU-R transmitter reference model........................................................8
`
`Transport capacity ..................................................................................9
`
`Simplex bearers......................................................................................9
`Duplex bearers .....................................................................................13
`Combined options.................................................................................14
`ADSL system overheads and aggregate data rates.............................17
`Classification by ATM options ..............................................................21
`
`ATU-C functional characteristics ..........................................................22
`
`ATU-C input and output V interfaces....................................................22
`Framing ................................................................................................23
`Scramblers ...........................................................................................35
`Forward error correction .......................................................................35
`Tone ordering .......................................................................................36
`Constellation encoder – with trellis coding ...........................................37
`Constellation encoder – without trellis coding ......................................45
`Gain scaling..........................................................................................45
`Modulation ............................................................................................46
`Cyclic prefix ..........................................................................................47
`Transmitter dynamic range...................................................................48
`Transmitter spectral response ..............................................................48
`Transmit power spectral density and aggregate power level ...............49
`
`ATU-R functional characteristics ..........................................................51
`
`ATU-R input and output data interfaces ...............................................51
`Framing ................................................................................................52
`Scramblers ...........................................................................................57
`Forward error correction .......................................................................57
`Tone ordering .......................................................................................57
`Constellation encoder – with trellis coding ...........................................57
`Constellation encoder – without trellis coding ......................................57
`Gain scaling..........................................................................................58
`Modulation ............................................................................................58
`Cyclic prefix ..........................................................................................59
`Transmitter dynamic range...................................................................60
`Transmitter spectral response ..............................................................61
`Transmit power spectral density and aggregate power level ...............62
`
`i
`
`

`
`Page
`ADSL – POTS splitter functional characteristics ..................................63
`ATU-R to service module (TSM ) interface requirements ......................64
`TA interface definitions..........................................................................64
`TB interface definitions..........................................................................65
`Electrical characteristics .......................................................................67
`
`dc characteristics..................................................................................67
`Voice-band characteristics ...................................................................67
`ADSL band ...........................................................................................69
`ADSL noise the interference into circuit POTS.....................................70
`
`Operations and maintenance ...............................................................71
`
`Embedded operations channel (eoc) requirements..............................71
`In-service performance monitoring and surveillance............................78
`Metallic testing......................................................................................84
`Out-of-service testing ...........................................................................84
`Requirements to support OAM of the segment between
`ATU-R and SM .....................................................................................84
`
`Initialization...........................................................................................87
`
`Overview...............................................................................................87
`Activation and acknowledgment – ATU-C............................................89
`Activation and acknowledgment – ATU-R............................................92
`Transceiver training – ATU-C ...............................................................93
`Transceiver training – ATU-R ...............................................................96
`Channel analysis – ATU-C ...................................................................98
`Channel analysis – ATU-R .................................................................102
`Exchange – ATU-C.............................................................................105
`Exchange – ATU-R.............................................................................108
`
`On-line adaptation and reconfiguration ..............................................112
`
`The ADSL overhead control (aoc) channel ........................................112
`High-level on-line adaptation – Bit swapping......................................112
`Changes to data rates and reconfiguration ........................................115
`
`Signaling requirements.......................................................................115
`
`Loop plant, impairments, and testing..................................................116
`
`Test loops ...........................................................................................117
`Impairments and their simulation in testing ........................................119
`Test procedures..................................................................................121
`
`Physical characteristics ......................................................................127
`
`Wiring polarity integrity .......................................................................127
`Connector ...........................................................................................127
`Wiring requirements for a remotely located POTS splitter/ATU-R .....128
`Maximum distance for a remotely located unit ...................................128
`
`Environmental conditions ...................................................................129
`
`Protection ...........................................................................................129
`Electromagnetic compatibility .............................................................129
`
`8
`
`9
`
`9.1
`9.2
`
`10
`
`10.1
`10.2
`10.3
`10.4
`
`11
`
`11.1
`11.2
`11.3
`11.4
`11.5
`
`12
`
`12.1
`12.2
`12.3
`12.4
`12.5
`12.6
`12.7
`12.8
`12.9
`
`13
`
`13.1
`13.2
`13.3
`
`14
`
`15
`
`15.1
`15.2
`15.3
`
`16
`
`16.1
`16.2
`16.3
`16.4
`
`17
`
`17.1
`17.2
`
`ii
`
`

`
`Tables
`
`Page
`
`1
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`2
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`3
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`4
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`5
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`6
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`7
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`8
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`9
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`10
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`11
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`12
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`13
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`14
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`15
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`16
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`17
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`18
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`19
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`20
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`21
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`22
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`23
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`24
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`25
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`26
`
`ADSL sub-channel rate restrictions for default bearer rates.................10
`
`ADSL sub-channel rate restrictions 2.048 Mbit/s (optional) .................11
`
`Downstream ATM data cell bit rates.....................................................12
`
`Maximum optional duplex bearer channels supported by
`transport class ......................................................................................14
`
`Optional duplex ATM data cell bit rates for LS2 ...................................14
`
`Bearer channel options by transport class for bearer rates based on
`downstream multiples of 1.536 Mbit/s ..................................................15
`
`Bearer channel options by transport class – Optional bearer rates
`based on downstream multiples of 2.048 Mbit/s ..................................16
`
`Bearer channel options by transport class for optional ATM
`bearer rates ..........................................................................................17
`
`Internal overhead channel functions and rates.....................................18
`
`Determination of aggregate downstream bit rate. ................................19
`
`Determination of aggregate upstream bit rate......................................20
`
`Determination of aggregate bit rate for ATM transport.........................21
`
`Interface data rates for duplex channels (default configurations).........23
`
`Definition of indicator bits, ATU-C transmitter ......................................25
`
`eoc frame stucture................................................................................26
`
`Default fast and interleaved data buffer allocations for ATU-C
`transmitter – Configurations for bearers based on multiples
`of 1.536 Mbit/s ......................................................................................27
`
`Default fast and interleaved data buffer allocations for ATU-C
`transmitter – Optional configurations for bearers based on
`multiples of 2.048 Mbit/s.......................................................................28
`
`Default FEC coding parameters and interleave depth for ATU-C
`transmitter – Default configurations for bearers based on multiples
`of 1.536 Mbit/s ......................................................................................30
`
`Default FEC coding parameters and interleave depth for ATU-C
`transmitter – Optional configurations for bearers based on
`multiples of 2.048 Mbit/s.......................................................................31
`
`Fast byte format....................................................................................32
`
`Synch byte format, interleaved data buffer...........................................33
`
`Convolutional interleaving example for N= 5, D= 2 ............................36
`
`Forming the binary word u....................................................................37
`
`Relation between 4-dimensional and 2-dimensional cosets.................42
`
`Determining the top 2 bits of X and Y...................................................44
`
`Default FEC coding parameters and interleave depth – ATU-R
`transmitter.............................................................................................54
`
`iii
`
`

`
`Page
`Fast byte format for synchronization – Fast data buffer .......................56
`
`Synch byte format for synchronization – Interleaved data buffer .........57
`
`Minimum voice-band return losses at PTSN and POTS interfaces......68
`
`eoc bit functions....................................................................................71
`
`eoc opcode messages..........................................................................74
`
`ATU-R data-registers............................................................................75
`
`Sync and no sync interpretation (downstream) ....................................85
`
`Sync and no sync interpretation for single SM .....................................85
`
`Sync and no sync interpretation for multiple SMs ................................86
`
`Assignment of 48 bits of C-MSGS1....................................................100
`
`Assignment of 48 bits of R-MSGS1....................................................103
`
`Assignment of 48 bits of C-MSGS2....................................................106
`
`Bit pattern for C-RATES2 ...................................................................107
`
`Assignment of 32 bits of R-MSGS2....................................................109
`
`Bit pattern for R-RATES2 ...................................................................110
`
`aoc message headers ........................................................................112
`
`Bit swap request commands ..............................................................113
`
`Extended bit swap request .................................................................114
`
`ATU classification by category ...........................................................117
`
`Loop sets and maximum rates for category I and category II testing....117
`
`Crosstalk tests for category I..............................................................123
`
`Crosstalk tests for category II.............................................................123
`
`Test loops, interferers, and data rates for impulse tests for category I.....124
`
`Test loops, interferers, and data rates for impulse tests for category II....124
`
`Test loops, interferers, and data rates for POTS tests for category I ....125
`
`Test loops, interferers, and data rates for POTS tests for category II ...125
`
`Minimum test time for crosstalk ..........................................................126
`
`Pin assignments for 8-position jack and plug (RJ 31X) at U-R...........127
`
`Pin assignments for 8-position jack and plug at remote location........128
`
`ADSL functional reference model...........................................................6
`
`ATU-C transmitter reference diagram ....................................................7
`
`ATU-R transmitter reference diagram ....................................................8
`
`ATU-C V interfaces (rates for default configuration).............................22
`
`ADSL superframe structure – ATU-C transmitter .................................24
`
`27
`
`28
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`29
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`30
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`31
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`32
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`33
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`34
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`35
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`36
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`37
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`38
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`39
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`40
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`41
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`42
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`43
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`44
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`45
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`46
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`47
`
`48
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`49
`
`50
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`51
`
`52
`
`53
`
`54
`
`55
`
`Figures
`
`1
`
`2
`
`3
`
`4
`
`5
`
`iv
`
`

`
`6
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`7
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`8
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`9
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`10
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`11
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`12
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`13
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`14
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`15
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`16
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`17
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`18
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`19
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`20
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`21
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`22
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`23
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`24
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`25
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`26
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`27
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`28
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`29
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`30
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`31
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`32
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`33
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`34
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`35
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`36
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`37
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`38
`
`39
`
`Page
`“Fast” byte format – ATU-C transmitter – fast data buffer ....................25
`
`“Synch” byte format – ATU-C transmitter – interleaved data buffer .....26
`
`Fast data buffer – ATU-C transmitter ...................................................28
`
`Interleaved data buffer – ATU-C transmitter.........................................29
`
`Conversion of uto vand w...................................................................38
`
`Finite state machine for Wei’s encoder ................................................39
`
`Trellis diagram ......................................................................................40
`
`Constituent 2-dimensional cosets for Wei’s code.................................41
`
`Constellation labels for b= 2 and b= 4................................................43
`
`Constellation labels for b= 3 ................................................................44
`
`Constellation labels for b= 5 ................................................................45
`
`ATU-C transmitter PSD mask...............................................................48
`
`ATU-C transmitter PSD mask: pass band detail ..................................50
`
`ATU-R data interfaces ..........................................................................51
`
`Fast data buffer – ATU-R transmitter ...................................................53
`
`Interleaved data buffer – ATU-R transmitter.........................................54
`
`ATU-R transmitter PSD mask...............................................................61
`
`ADSL entrance unit block diagram.......................................................66
`
`Test setup for transmission and impedance measurements................67
`
`Measurement method for longitudinal output voltage...........................69
`
`Measurement method for longitudinal balance above 25 kHz..............70
`
`In-service surveillance of the ADSL link shown from the standpoint
`of the ATU-C.........................................................................................79
`
`OAM capabilities for the segment between ATU-R and the service
`module..................................................................................................84
`
`Overview of initialization .......................................................................87
`
`Timing diagram of activation and acknowledgment (12.2-12.3)...........89
`
`Timing diagram of transceiver training (12.4-12.5)...............................93
`
`Timing diagram of channel analysis (12.6-12.7)...................................98
`
`C-RATES1 and R-RATES1 (12.6.2 and 12.7.4)...................................99
`
`Timing diagram of exchange (12.8-12.9)............................................105
`
`Format of the bit swap request message ...........................................113
`
`Format of the bit swap acknowledge..................................................114
`
`Overview of test setup........................................................................116
`
`Test loops ...........................................................................................118
`
`Test impulse #1 ..................................................................................120
`
`v
`
`

`
`40
`
`41
`
`42
`
`43
`
`44
`
`Page
`Test impulse #2 ..................................................................................120
`
`Laboratory test setup for measuring performance margins................121
`
`High impedance crosstalk injection circuit..........................................122
`
`Interface on the customer premises side of the U-R ..........................127
`
`Wiring for a remotely located POTS splitter/ATU-R ...........................128
`
`Annexes
`
`ATU-C and ATU-R state diagrams ....................................................130
`
`Power spectral density of crosstalk disturbers ..................................137
`
`Characteristics of test impulse waveforms ........................................147
`
`Vendor identification numbers ...........................................................153
`
`Resistance and insertion loss characteristics of typical telephone
`cables .................................................................................................154
`
`Overvoltage, surge protection, and EMC ..........................................156
`
`Examples of ADSL services and applications ...................................157
`
`Aspects of ADSL systems based 2048 Mkbit/s .................................160
`
`Items for further study.........................................................................169
`
`Bibliography........................................................................................170
`
`A
`
`B
`
`C
`
`D
`
`E
`
`F
`
`G
`
`H
`
`I
`
`J
`
`vi
`
`

`
`Foreword (This foreword is not part of American National Standard T1.413-1995.)
`
`This specification of the layer 1 characteristics of the Asymmetrical Digital
`Subscriber Line (ADSL) interface to metallic loops was initiated under the
`auspices of the Accredited Standards Committee on Telecommunications,
`T1. The specification should be of interest and benefit to network providers
`and customers using multimedia services.
`
`A single twisted pair of telephone wires is used to connect two ADSL units:
`one at the central office end (an ATU-C) and one at the remote end (an
`ATU-R). This standard has been written to define the transport capability
`of these units on a wide variety of wire pairs and with typical impairments,
`and to help ensure proper interfacing and interworking when the two units
`are manufactured and provided independently.
`
`The ADSL simultaneously conveys all of the following: a downstream simplex
`bearer, a duplex bearer, a baseband analog duplex channel, and ADSL line
`overhead for framing, error control, operations, and maintenance. Nominal
`downstream bearer rates from 1.536 to 7 Mbit/s may be programmed. Duplex
`bearer aggregate rates from 16 to 640 kbit/s may be programmed.
`
`Two categories of performance are specified. Category I performance is
`required for compliance with this standard; performance enhancement
`options are not required for category I equipment. Category II is a higher
`level of performance (i.e., longer lines and greater impairments). Category
`II characteristics are not required for compliance with this standard. Three
`optional enhancements – trellis coding, transmit power boost, and echo
`cancellation – are defined for Category II equipment.
`
`A future issue of this standard may address the items listed in annex J.
`
`There are nine annexes to this standard; four are normative, and are con-
`sidered part of the standard; five are informative, and are provided for
`information only.
`
`Suggestions for improvements of this standard are welcome. They should
`be sent to the Alliance for Telecommunications Industries Solutions, 1200
`G Street, NW, Suite 500, Washington, DC 20005.
`
`This standard was processed and approved for submission to ANSI by
`Accredited Standards Committee on Telecommunications T1. Committee
`approval of the standard does not necessarily imply that all committee
`members voted for its approval. At the time it approved this standard, com-
`mittee T1 had the following members:
`
`A. K. Reilly, Chairman
`G. H. Peterson, Vice-Chairman
`O. J. Gusella, Jr., Secretary
`
`R. Welborn, Senior Editor
`J. Bingham, Technical Editor
`
`Organization Represented
`EXCHANGE CARRIERS
`Ameritech Services, Inc. ....................................................Laurence A. Young
`Stephen P. Murphy (Alt.)
`Bell Atlantic Corporation ....................................................John W. Seazholtz
`Roger Nucho (Alt.)
`
`Name of Representative
`
`vii
`
`

`
`Organization Represented
`Name of Representative
`Bellcore.............................................................................James C. Staats
`E. R. Hapeman (Alt.)
`BellSouth Telecommunications, Inc. ..................................William J. McNamara, III
`Malcolm Threlkeld, Jr. (Alt.)
`Cincinnati Bell Telephone ..................................................Thomas C. Grimes
`Renee W. Cagle (Alt.)
`GTE Telephone Operations ...............................................Bernard J. Harris
`Richard L. Cochran (Alt.)
`National Telephone Cooperative Association .....................Joseph M. Flanagan
`NYNEX .............................................................................James F. Baskin
`Jim Papadopoulos (Alt.)
`Pacific Bell ........................................................................Sal R. Tesoro
`Puerto Rico Telephone Company.......................................Segundo Ruiz
`Alberto E. Morales (Alt.)
`Southwestern Bell Corporation ..........................................C. C. Bailey
`Joseph Mendoza (Alt.)
`Sprint – Local Telecommunications Division.......................Robert P. McCabe
`Harold L. Fuller (Alt.)
`US Telephone Association (USTA) ....................................Dennis Byrne
`Paul K. Hart (Alt.)
`US WEST..........................................................................James L. Eitel
`Darryl Debault (Alt.)
`
`INTEREXCHANGE CARRIERS
`AT&T Communications ......................................................Charles A. Dvorak
`Dennis Thovson (Alt.)
`Comsat Corporation ..........................................................Mark T. Neibert
`Thanos Kipreos (Alt.)
`MCI Telecommunications Corporation................................Jim Joerger
`Peter Guggina (Alt.)
`Sprint – Long Distance Division .........................................Tom G. Croda
`Peter J. May (Alt.)
`Stentor Resource Centre, Inc.............................................Michel Duchesne
`B. Sambasivan (Alt.)
`Unitel Communications, Inc. ..............................................David H. Whyte
`George Tadros (Alt.)
`Wiltel, Inc. .........................................................................Robert Bentley
`Howard Meiseles (Alt.)
`
`MANUFACTURERS
`ADC Telecommunications, Inc. ..........................................Ron Weitnauer
`Don Berryman (Alt.)
`Alcatel Network Systems, Inc.............................................Bob Cubbage
`Dale Krisher (Alt.)
`AMP, Inc. ..........................................................................George Lawrence
`Jack Bradbery (Alt.)
`Apple Computer, Inc. .........................................................David Michael
`Ascom Timeplex, Inc. ........................................................L. H. Eberl
`Richard Koepper (Alt.)
`AT&T Network Systems .....................................................John H. Bobsin
`Dave R. Andersen (Alt.)
`DSC Communications Corporation .....................................Peter Waal
`Allen Adams (Alt.)
`ECI Telecom, Inc. ..............................................................Ron Murphy
`Charles T. Throop (Alt.)
`Ericsson, Inc. ....................................................................Linda Troy
`Al Way (Alt.)
`Fujitsu America, Inc. ..........................................................Kenneth T. Coit
`Ashok Saraf (Alt.)
`General DataComm, Inc. ...................................................Frederick Lucas
`Frederick Cronin (Alt.)
`Harris Corporation .............................................................Allen Jackson
`Yogi Mistery (Alt.)
`Hekimian Laboratories .......................................................William H. Duncan
`Mike F. Toohig (Alt.)
`Hewlett-Packard ................................................................Don C. Loughry
`Richard van Gelder (Alt.)
`
`viii
`
`

`
`Organization Represented
`Name of Representative
`Hitachi Telecomm USA, Inc. ..............................................Bryan Hall
`Pat Kunza (Alt.)
`IBM Corporation ................................................................William C. Bergman
`Rao J. Cherukuri (Alt.)
`Mitel Corporation ...............................................................John Needham
`F. Audet (Alt.)
`Motorola, Inc. ....................................................................Edmund J. Downey
`Dan Grossman (Alt.)
`NEC America, Inc. .............................................................Donovan Nak
`Masaki Omura (Alt.)
`Northern Telecom, Inc. ......................................................Mel N. Woinsky
`Subhash Patel (Alt.)
`Picturetel Corporation........................................................Marshall Schachtman
`David Lindbergh (Alt.)
`Reliance Comm/Tec ..........................................................Mark Scott
`Leroy Baker (Alt.)
`Rockwell International Corporation ....................................Quent C. Cassen
`Carl J. Stehman (Alt.)
`Siemens Stromberg-Carlson ..............................................Michael A. Pierce
`Robert Poignant (Alt.)
`Telecom Solutions .............................................................M. J. Narasimha
`Don Chislow (Alt.)
`Telecommunications Techniques Corporation ....................Bernard E. Worne
`Tellabs Operations, Inc......................................................R. Michael Schafer
`Michael J. Birck (Alt.)
`Transwitch Corporation......................................................Daniel C. Upp
`Praveen Goli (Alt.)
`
`GENERAL INTEREST
`Ashford Associates............................................................Donald A. Ashford
`Brooktree Corporation ......................................