INTERNATIONAL TELECOMMUNICATION UNION
`
`)45 4
`
`TELECOMMUNICATION
`STANDARDIZATION SECTOR
`OF ITU
`
`6(cid:14)(cid:19)(cid:18)
`(03/93)
`
`$!4!#/--5.)#!4)/./6%2
`4(%4%,%0(/.%.%47/2+
`
`!&!-),9/&(cid:18) 7)2%(cid:12)$50,%8-/$%-3
`/0%2!4).’!4$!4!3)’.!,,).’2!4%3
`/&504/(cid:25)(cid:22)(cid:16)(cid:16)BIT(cid:15)S&/253%/.
`4(%’%.%2!,37)4#(%$4%,%0(/.%
`.%47/2+!.$/.,%!3%$
`4%,%0(/.% 490%#)2#5)43
`
`)45 4Recommendation6(cid:14)(cid:19)(cid:18)
`
`(Previously “CCITT Recommendation”)
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 1 of 27
`
`

`

`FOREWORD
`
`The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecom-
`munication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing
`Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
`
`The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the
`topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics.
`
`ITU-T Recommendation V.32 was revised by the ITU-T Study Group XVII (1988-1993) and was approved by the
`WTSC (Helsinki, March 1-12, 1993).
`
`___________________
`
`NOTES
`
`As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT
`1
`ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was
`created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the
`Radiocommunication Sector.
`
`In order not to delay publication of this Recommendation, no change has been made in the text to references containing
`the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future
`editions of this Recommendation will contain the proper terminology related to the new ITU structure.
`
`In this Recommendation, the expression “Administration” is used for conciseness to indicate both a
`2
`telecommunication administration and a recognized operating agency.
`
`All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or
`mechanical, including photocopying and microfilm, without permission in writing from the ITU.
`
`ª ITU 1993
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 2 of 27
`
`

`

`Recommendation V.32 (03/93)
`
`CONTENTS
`
`1
`
`2
`
`3
`
`4
`
`5
`
`6
`
`7
`
`Introduction ....................................................................................................................................................
`
`Line signals ....................................................................................................................................................
`2.1
`Carrier frequency ..............................................................................................................................
`2.2
`Transmitted spectrum .......................................................................................................................
`2.3
`Modulation rate.................................................................................................................................
`2.4
`Coding ..............................................................................................................................................
`
`Interchange circuits ........................................................................................................................................
`3.1
`List of interchange circuits ...............................................................................................................
`3.2
`Transmit data ....................................................................................................................................
`3.3
`Receive data......................................................................................................................................
`3.4
`Timing arrangements ........................................................................................................................
`3.5
`Data rate control ...............................................................................................................................
`3.6
`Circuit 106 ........................................................................................................................................
`3.7
`Circuit 109 ........................................................................................................................................
`3.8
`Electrical characteristics of interchange circuits...............................................................................
`3.9
`Fault condition on interchange circuits.............................................................................................
`
`Scrambler and descrambler ............................................................................................................................
`4.1
`Scrambler/descrambler allocation.....................................................................................................
`
`Operating procedures .....................................................................................................................................
`5.1
`Recommendation V.25 automatic answering sequence....................................................................
`5.2
`Receiver conditioning signal ............................................................................................................
`5.3
`Rate signal ........................................................................................................................................
`5.4
`Start-up procedure ............................................................................................................................
`5.5
`Retrain procedure..............................................................................................................................
`
`Testing facilities .............................................................................................................................................
`
`Asynchronous to synchronous conversion protocol – Modes of operation ...................................................
`7.1
`Transmitter........................................................................................................................................
`7.2
`Receiver ............................................................................................................................................
`
`Annex A ....................................................................................................................................................................
`A.1
`Definitions of Terms Used................................................................................................................
`A.2
`Interworking of Duplex Modems .....................................................................................................
`
`Appendix I – Interworking procedure for echo cancelling modems .........................................................................
`I.1
`Interworking of echo cancelling modems.........................................................................................
`
`Page
`
`1
`
`1
`1
`2
`2
`2
`
`3
`3
`3
`4
`4
`4
`5
`5
`5
`6
`
`6
`8
`
`9
`9
`9
`10
`13
`15
`
`16
`
`16
`16
`16
`
`17
`17
`17
`
`20
`20
`
`Recommendation V.32 (03/93)
`
`i
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 3 of 27
`
`

`

`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 4 of 27
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 4 of 27
`
`

`

`Recommendation V.32
`
`Recommendation V.32 (03/93)
`
`A FAMILY OF 2-WIRE, DUPLEX MODEMS OPERATING AT
`DATA SIGNALLING RATES OF UP TO 9600 bit/s FOR USE
`ON THE GENERAL SWITCHED TELEPHONE NETWORK
`AND ON LEASED TELEPHONE-TYPE CIRCUITS
`
`(Malaga-Torremolinos, 1984, amended Melbourne, 1988
`and Helsinki, 1993)
`
`1
`
`Introduction
`
`This family of modems is intended for use on connections on general switched telephone networks (GSTNs) (see
`Note 1) and on point-to-point leased telephone-type circuits. The principal characteristics of the modems are as follows:
`
`a) Duplex mode of operation on GSTN and 2-wire point-to-point leased circuits (see Note 2).
`
`b) Channel separation by echo cancellation techniques.
`
`c) Quadrature amplitude modulation for each channel with synchronous line transmission at 2400 bauds.
`
`d) Any combination of the following data signalling rates may be implemented in the modems:
`
`9600 bit/s synchronous (optional),
`
`4800 bit/s synchronous (mandatory),
`
`2400 bit/s synchronous (for further study).
`
`e) At 9600 bit/s, two alternative modulation schemes, one using 16 carrier states and one using trellis coding
`with 32 carrier states, are provided for in this Recommendation. However, modems providing the
`9600 bit/s data signalling rate shall be capable of interworking using the 16-state alternative.
`
`f)
`
`Exchange of rate sequences during start-up to establish the data rate, coding and any other special
`facilities.
`
`g) Optional provision of an asynchronous mode of operation in accordance with Recommendations V.14
`or V.42.
`
`NOTES
`
`On international GSTN connections that utilize circuits that are in accord with Recommendation G.235 (16-channel
`1
`terminal equipments), it may be necessary to employ a greater degree of equalization within the modem than would be required for
`use on most national GSTN connections.
`
`2
`further study.
`
`The transmit and receive rates in each modem shall be the same. The possibility of asymmetric working remains for
`
`2
`
`Line signals
`
`2.1
`
`Carrier frequency
`
`The carrier frequency is to be 1800 – 1 Hz. No separate pilot tones are to be provided. The receiver must be able to
`operate with received frequency offsets of up to –
` 7 Hz.
`
`Recommendation V.32 (03/93)
`
`1
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 5 of 27
`
`

`

`2.2
`
`Transmitted spectrum
`
`The transmitted power level must conform to Recommendation V.2. With continuous binary ones applied to the input of
`the scrambler, the transmitted energy density at 600 Hz and 3000 Hz should be attenuated 4.5 –
` 2.5 dB with respect to
`the maximum energy density between 600 Hz and 3000 Hz.
`
`Modulation rate
`2.3
`The modulation rate shall be 2400 bauds –
`
` 0.01%.
`
`2.4
`
`Coding
`
`2.4.1
`
`Signal element coding for 9600 bit/s
`
`Two alternatives are defined.
`
`2.4.1.1 Nonredundant coding
`
`The scrambled data stream to be transmitted is divided into groups of 4 consecutive data bits. The first two bits in time
`Q1n and Q2n in each group, where the subscript n designates the sequence number of the group, are differentially
`encoded into Y1n and Y2n according to Table 1. Bits Y1n, Y2n, Q3n and Q4n are then mapped into the coordinates of the
`signal state to be transmitted according to the signal space diagram shown in Figure 1 and as listed in Table 3.
`
`Differential quadrant coding for 4800 bit/s and for nonredundant coding at 9600 bit/s
`
`TABLE 1/V.32
`
`Inputs
`
`Previous outputs
`
`Phase quadrant change
`
`Q1n
`
`Q2n
`
`Y1n – 1
`
`Y2n – 1
`
`Outputs
`
`Y1n
`
`Y2n
`
`Signal state
`for 4800 bit/s
`
`0
`0
`0
`0
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`1
`1
`1
`1
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`+190º
`
`+190º
`
`+180º
`
`+270º
`
`0
`1
`0
`1
`
`0
`0
`1
`1
`
`1
`1
`0
`0
`
`1
`0
`1
`0
`
`1
`1
`0
`0
`
`0
`1
`0
`1
`
`1
`0
`1
`0
`
`0
`0
`1
`1
`
`B
`C
`A
`D
`
`A
`B
`D
`C
`
`C
`D
`B
`A
`
`D
`A
`C
`B
`
`2
`
`Recommendation V.32 (03/93)
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 6 of 27
`
`

`

`1011
`
`D
`
`1001
`
`(Im)
`90°
`
`2
`
`1110
`
`1111
`
`1010
`
`1000
`
`1100
`
`C
`
`1101
`
`2
`
`0°
`
`(Re)
`
`180°
`
`–2
`
`A
`
`0001
`
`0000
`
`0100
`
`0110
`
`0011
`
`0010
`
`–2
`
`B
`
`270°
`
`0101
`
`0111
`
`T1702130-93/d01
`
`NOTE – The binary numbers denote Y1 Y2 Q3 Q4
`n
`n
`n
`
`n
`
`FIGURE 1/V.32
`16-point signal structure with nonredundant coding for 9600 bit/s
`and subset A B C and D of states used at 4800 bit/s and for training
`
`FIGURE 1/V.32...[D01] = 10.5 CM
`
`2.4.1.2 Trellis coding
`
`The scrambled data stream to be transmitted is divided into groups of 4 consecutive data bits. As shown in Figure 2, the
`first two bits in time Q1n and Q2n in each group, where the subscript n designates the sequence number of the group, are
`first differentially encoded into Y1n and Y2n according to Table 2. The two differentially encoded bits Y1n and Y2n are
`used as input to a systematic convolutional encoder which generates a redundant bit Y0n. This redundant bit and the 4
`information-carrying bits Y1n, Y2n, Q3n and Q4n are then mapped into the coordinates of the signal element to be
`transmitted according to the signal space diagram shown in Figure 3 and as listed in Table 3.
`
`2.4.2
`
`Signal element coding for 4800 bit/s
`
`The scrambled data stream to be transmitted is divided into groups of 2 consecutive data bits. These bits, denoted Q1n
`and Q2n, where Q1n is the first in time, and the subscript n designates the sequence number of the group, are
`differentially encoded into Y1n and Y2n according to Table 1. Figure 1 shows the subset A, B, C and D of signal states
`used for 4800 bit/s transmission.
`
`2.4.3
`
`Signal element coding for 2400 bit/s
`
`For further study.
`
`3
`
`Interchange circuits
`
`3.1
`
`List of interchange circuits
`
`These are listed in Table 4.
`
`3.2
`
`Transmit data
`
`The modems shall accept synchronous data from the DTE on circuit 103 under control of circuit 113 or 114.
`
`Recommendation V.32 (03/93)
`
`3
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 7 of 27
`
`

`

`nQ4
`
`Q3
`
`n
`
`Q2
`
`n
`
`Q1n
`
`See
`Table 2
`
`Y2
`
`n
`
`Y1
`n
`
`Y2
`
`n–1
`
`T
`
`Y1n–1
`
`T
`
`Signal
`element
`mapping
`(see
`Figure 3
`or
`Table 3)
`
`nQ4
`
`Q3
`
`n
`
`Y2
`
`n
`
`Y1
`n
`
`nY0
`
`+
`
`+
`
`T
`
`+
`
`T
`
`+
`
`+
`
`T
`
`Differential encoder
`
`Convolutional encoder
`
`T1702140-93/d02
`
`S1
`
`S2
`
`b
`
`+
`
`a
`
`a b
`
`0
`
`0
`
`1
`
`1
`
`1
`
`0
`
`1
`
`0
`
`1
`
`0
`
`11
`
`FIGURE 2/V.32
`Trellis coding at 9600 bit/s
`
`FIGURE 2/V.32...[D02] = 15 CM
`
`3.3
`
`Receive data
`
`The modems shall pass synchronous data to the DTE on circuit 104 under the control of circuit 115.
`
`3.4
`
`Timing arrangements
`
`Clocks shall be included in the modems to provide the DTE with transmitter signal element timing on circuit 114 and
`receiver signal element timing on circuit 115. The transmitter timing may originate in the DTE and be transferred to the
`modem via circuit 113. In some applications it may be necessary to slave the transmitter timing to the receiver timing
`inside the modem.
`
`3.5
`
`Data rate control
`
`Data rate selection may be by switch (or similar means) or alternatively by circuit 111. In cases where three different
`data signalling rates are implemented in a modem, a manual selector may be provided which determines the two data
`signalling rates selected by circuit 111.
`
`The ON condition of circuit 111 selects the higher data signalling rate and the OFF condition of circuit 111 selects the
`lower data signalling rate.
`
`4
`
`Recommendation V.32 (03/93)
`
`Symbol truth table
`S1 S2
`0
`0
`
`b
`
`0
`
`a
`
`0
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 8 of 27
`
`

`

`TABLE 2/V.32
`
`Differential encoding for use with trellis coded alternative at 9600 bit/s
`
`Inputs
`
`Previous outputs
`
`Outputs
`
`Q1n
`
`Q2n
`
`Y1n – 1
`
`Y2n – 1
`
`Y1n
`
`Y2n
`
`0
`0
`0
`0
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`1
`
`1
`
`1
`1
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`0
`0
`0
`0
`
`1
`
`1
`
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`
`0
`
`1
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`
`1
`
`0
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`1
`1
`0
`0
`
`1
`
`1
`
`0
`0
`
`0
`1
`0
`1
`
`1
`0
`1
`0
`
`0
`1
`1
`0
`
`1
`
`0
`
`0
`1
`
`3.6
`
`Circuit 106
`
`After the start-up and retrain sequences, circuit 106 must follow the state of circuit 105 within 2 ms.
`
`3.7
`
`Circuit 109
`
`OFF to ON and ON to OFF transitions of circuit 109 should occur solely in accordance with the operating sequences
`defined in 5. Thresholds and response times are inapplicable because a line signal detector cannot be expected to
`distinguish wanted received signals from unwanted talker echoes.
`
`3.8
`
`Electrical characteristics of interchange circuits
`
`3.8.1
`Use of electrical characteristics conforming to Recommendation V.28 is recommended together with the
`connector and pin assignment plan specified by ISO 2110.
`
`NOTE – Manufacturers may wish to note that the long-term objective is to replace electrical characteristics specified in
`Recommendation V.28, and that Study Group XVII has agreed that the work shall proceed to develop a more efficient, all-balanced,
`interface for the V-Series application which minimizes the number of interchange circuits.
`
`Recommendation V.32 (03/93)
`
`5
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 9 of 27
`
`

`

`(Im)
`90°
`
`4
`
`11111
`
`11000
`
`01000
`
`D
`
`00101
`2
`
`01010
`
`10010
`
`10101
`
`10011
`
`10100
`
`00000
`
`01111
`
`00010
`
`01101
`
`C
`
`00011
`
`180°
`
`–4
`
`11001
`
`–2
`
`11110
`
`11010
`
`2
`
`11101
`
`4
`
`0°
`
`(Re)
`
`A
`
`00111
`
`01001
`
`00110
`–2
`
`01011
`
`00100
`
`10000
`
`10111
`
`10001
`
`10110
`
`01110
`
`B
`
`01100
`
`00001
`–4
`
`11100
`
`11011
`
`270°
`
`T1702150-93/d03
`
`NOTE – The binary numbers denote Y0 Y1 Y2 Q3 Q4 .
`n
`n
`n
`n
`n
`
`FIGURE 3/V.32
`32-point signal structure with trellis coding for 9600 bit/s
`and states A B C and D used at 4800 bit/s and for training
`
`FIGURE 3/V.32...[D03] = 12 CM
`
`3.9
`
`Fault condition on interchange circuits
`
`See 7/V.28 for association of the receiver failure detection types.
`
`3.9.1
`
`The DTE should interpret a fault condition on circuit 107 as an OFF condition using failure detection type 1.
`
`3.9.2
`type 1.
`
`The DCE should interpret a fault condition on circuits 105 and 108 as an OFF condition using failure detection
`
`3.9.3
`
`All other circuits not referred to above may use failure detection types 0 or 1.
`
`4
`
`Scrambler and descrambler
`
`A self-sychronizing scrambler/descrambler shall be included in the modem. Each transmission direction uses a different
`scrambler. The method of allocating the scramblers/descramblers is described in 4.1. According to the direction of
`transmission, the generating polynomial is:
`
`Call mode modem generating polynomial: (GPC) = 1 + x–18 + x–23; or
`
`Answer mode modem generating polynomial: (GPA) = 1 + x–5 + x–23
`
`At the transmitter, the scrambler shall effectively divide the message data sequence by the generating polynomial. The
`coefficients of the quotients of this division, taken in descending order, form the data sequence which shall appear at the
`output of the scrambler. At the receiver the received data sequence shall be multiplied by the scrambler generating
`polynomial to recover the message sequence.
`
`6
`
`Recommendation V.32 (03/93)
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 10 of 27
`
`

`

`TABLE 3/V.32
`
`The two alternative signal-state mappings for 9600 bit/s
`
`Coded inputs
`(see Table 1 or Table 2 with Figure 2)
`
`Nonredundant coding
`
`Trellis coding
`
`(Y0)
`
`Y1
`
`Y2
`
`Q3
`
`Q4
`
`Re
`
`–1
`–3
`–1
`–3
`
`–1
`–1
`–3
`–3
`
`–1
`–1
`–3
`–3
`
`–1
`–3
`–1
`–3
`
`0
`
`1
`
`0
`0
`0
`0
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`1
`1
`1
`1
`
`0
`0
`0
`0
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`1
`1
`1
`1
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`0
`0
`0
`0
`
`1
`1
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`0
`1
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`0
`1
`0
`1
`
`Im
`
`–1
`–1
`–3
`–3
`
`–1
`–3
`–1
`–3
`
`–1
`–3
`–1
`–3
`
`–1
`–1
`–3
`–3
`
`Re
`
`– 4
`–0
`–0
`4
`
`–4
`–0
`–0
`– 4
`
`–2
`–2
`–2
`–2
`
`–2
`–2
`–2
`–2
`
`–3
`–1
`–3
`–1
`
`–3
`–1
`–3
`–1
`
`–1
`–3
`–1
`–1
`
`–1
`–3
`–1
`–1
`
`Im
`
`–1
`–3
`–1
`–1
`
`–1
`–3
`–1
`–1
`
`–3
`–1
`–3
`–1
`
`–3
`–1
`–3
`–1
`
`–2
`–2
`–2
`–2
`
`–2
`–2
`–2
`–2
`
`–4
`–0
`–0
`– 4
`
`– 4
`–0
`–0
`–4
`
`Recommendation V.32 (03/93)
`
`7
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 11 of 27
`
`

`

`TABLE 4/V.32
`
`Interchange circuit (see Note 1)
`
`Description
`
`Signal ground or common return
`
`Transmitted data
`Received data
`Request to send
`Ready for sending
`
`No.
`
`102
`
`103
`104
`105
`106
`
`107
`108/1 or
`108/2
`109
`
`Data set ready
`Connect data set to line
`Data terminal ready
`Data channel received line signal detector
`
`111
`112
`113
`114
`115
`125
`140
`141
`142
`
`Data signalling rate selector (DTE source)
`Data signalling rate selector (DCE source)
`Transmitter signal element timing (DTE source)
`Transmitter signal element timing (DCE source)
`Receiver signal element timing (DCE source)
`Calling indicator
`Loopback/maintenance test
`Local loopback
`Test indicator
`
`Notes
`
`2
`2
`
`3
`3
`5
`6
`6
`4
`
`NOTES
`1 All interchange circuits which are provided shall comply with the functional and operational requirements of
`Recommendation V.24. All interchange circuits shall be properly terminated in the data terminal equipment and in
`the data circuit-terminating equipment in accordance with the appropriate Recommendation for electrical
`characteristics (see 3.8).
`2 This circuit shall be capable of operation as circuit 108/1 or circuit 108/2 depending on its use. Operation of
`circuits 107 and 108/1 shall be in accordance with 4.4/V.24.
`3 This circuit is not essential when only one data signalling rate is implemented in the modem.
`4 This circuit is for use with the general switched telephone network only.
`5 When the modem is not operating in a synchronous mode at the interface, any signals on this circuit shall be
`disregarded. Many DTEs operating in an asynchronous mode do not have a generator connected to this circuit.
`6 When the modem is not operating in a synchronous mode at the interface, this circuit shall be clamped to the
`OFF condition. Many DTEs operating in an asynchronous mode do not terminate this circuit.
`
`4.1
`
`Scrambler/descrambler allocation
`
`4.1.1
`
`General switched telephone network (GSTN)
`
`On the general switched telephone network, the modem at the calling data station (call mode) shall use the scrambler
`with the GPC generating polynomial and the descrambler with the GPA generating polynomial. The modem at the
`answering data station (answer mode) shall use the scrambler with the GPA generating polynomial and the descrambler
`with the GPC generating polynomial. In some situations, however, such as when calls are established on the GSTN by
`operators, bilateral agreement on call mode/answer mode allocation will be necessary.
`
`8
`
`Recommendation V.32 (03/93)
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 12 of 27
`
`

`

`4.1.2
`
`Point-to-point leased circuits
`
`Scrambler/descrambler allocation and call mode and answer mode designation on point-to-point leased circuits will be
`by bilateral agreement between Administrations or users.
`
`5
`
`5.1
`
`Operating procedures
`
`Recommendation V.25 automatic answering sequence
`
`The Recommendation V.25 automatic answering sequence shall be transmitted from the answer mode modem on
`international GSTN connections. The transmission of the sequence may be omitted on point-to-point leased circuits or
`on national connections on the GSTN where permitted by Administrations. In this event, the answer mode modem shall
`initiate transmission as in the retrain procedure specified in 5.5.
`
`5.2
`
`Receiver conditioning signal
`
`The receiver conditioning signal shall be used in the start-up and retrain procedures defined in 5.4 and 5.5. The signal
`consists of three segments:
`
`5.2.1
`Segment 1, denoted by S in Figures 4 and 5, consists of alternations between states A and B as shown in
`Figure 1, for a duration of 256 symbol intervals.
`
`5.2.2
`Segment 2, denoted by S in Figures 4 and 5, consists of alternations between states C and D as shown in
`Figure 1, for a duration of 16 symbol intervals.
`
`The transition from segment 1 to segment 2 provides a well-defined event in the signal that may be used for generating a
`time reference in the receiver.
`
`5.2.3
`Segment 3, denoted by TRN in Figures 4 and 5, is a sequence derived by scrambling binary ones at a data rate
`of 4800 bit/s with the scrambler defined in 4. During the transmission of this segment, the differential quadrant encoding
`shall be disabled. The initial state of the scrambler shall be all zeros, and a binary one applied to the input for the
`duration of segment 3. Successive dibits are encoded onto transmitted signal states.
`
`The first 256 transmitted signal states are determined from the state of the first bit occurring (in time) in each dibit.
`When this bit is ZERO, signal state A is transmitted; when this bit is ONE, signal state C is transmitted. Depending on
`whether the modem is in call or answer mode, the scrambler output patterns and corresponding signal states will then
`begin as below, where the bits and the signal states are shown in time sequence from left to right.
`
`Call mode modem:
`GPC:
`GPC:
`
`11 11 11 11 11 11 11 11 11 00 00 01 11 11 11
`C C C C C C C C C A A A C C C
`
`Answer mode modem:
`GPA:
`11 11 10 00 00 11 11 10 00 00 11 10 01 11 11
`GPA:
`C C C A A C C C A A C C A C C
`
`Immediately after 256 such symbols, successive scrambled dibits are encoded onto transmitted signal states in
`accordance with Table 5 directly without differential encoding for the remainder of segment 3. The duration of
`segment 3 shall be at least 1280 and not exceed 81921) symbol intervals.
`
`Segment 3 is intended for training the adaptive equalizer in the receiving modem and the echo canceller in the
`transmitting modem.
`
`_______________
`
`1) The maximum duration of 8192 symbol intervals is for further study.
`
`Recommendation V.32 (03/93)
`
`9
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 13 of 27
`
`

`

`64T ± 2T
`
`NT
`
`256T
`
`1280T
`
`8T 128T
`
`Call
`mode
`modem
`
`AA
`
`CC
`
`NT
`
` 1 second
`
`S
`
`S S TRN
`
`Rate signal R2
`
`E
`
`B1
`
`Data
`
`(Note)
`
`16T
`
`107
`
`106
`
`Unclamp 104
`
`109
`
`(Note)
`
`64T
`
`MT
`
`16T
`
`16T
`
`128T
`
`ANS
`
`AC
`
`CA
`
`AC
`
`S S TRN
`
`R1
`
`S S TRN
`
`R3
`
`E
`
`B1
`
`Data
`
`Answer
`mode
`modem
`
`V25
`
`128T
`
`64T ± 2T
`
`16T
`
`256T
`
`1280T
`
`256T
`
`1280T
`
`8T
`
`107
`
`106
`
`Unclamp 104
`
`109
`T1701530-92/d04
`
`Signal states ACAC..AC for an even number of symbol intervals T; similarly with CA, AA and CC.
`Round-trip delays observed from answer and call modems respectively, including 64T ± 2T modem turn round delay.
`Signal states ABAB..AB, CDCD..CD.
`Scrambled ones at 4800 bit/s with dibits encoded directly to states A, B, C and D as defined in 5.2.3.
`Each a repeated 16-bit rate sequence at 4800 bit/s scrambled and differentially encoded as in Table 1.
`A single 16-bit sequence marking and following the end of a whole number of 16-bit rate sequences in R2 and R3.
`Binary ones scrambled and encoded as for the subsequent transmission of data.
`
`AC
`MT, NT
`S, S
`TRN
`R1, R2, R3
`
`EB
`
`1
`
`NOTE – The inclusion of a special echo canceller training sequence at this point is optional (see 5.4, Note 3).
`
`FIGURE 4/V.32
`Start-up procedure
`
`FIGURE 4/V.32...[D04] = 15 CM
`
`5.3
`
`Rate signal
`
`The rate signal consists of a whole number of repeated 16-bit binary sequences, as defined in Table 6, scrambled and
`transmitted at 4800 bit/s with dibits differentially encoded as in Table 1. The differential encoder shall be initialized
`using the final symbol of the transmitted TRN segment.
`
`The first two bits and each successive dibit of the rate sequence shall be encoded to form the transmitted signal states.
`
`5.3.1
`
`Detecting a rate signal
`
`The minimum requirement for detection is the receipt of two consecutive identical 16-bit sequences each with bits B0-3,
`B7, 11 and 15 conforming to Table 6.
`
`5.3.2
`
`Ending the rate signal
`
`In order to mark the end of transmission of any rate signal other than R1 (Figure 4), the modem shall first complete the
`transmission of the current 16-bit rate sequence, and then transmit one 16-bit sequence E, coded as shown in Table 7.
`
`10
`
`Recommendation V.32 (03/93)
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 14 of 27
`
`‡
`‡
`‡
`‡
`‡
`‡
`

`

`Call
`mode
`modem
`
`Data
`
`Answer
`mode
`modem
`
`Data
`
`64T ± 2T
`
`NT
`
`256T
`
`1280T
`
`8T 128T
`
`CC
`
`NT
`
`AA
`
`106
`
`Clamp 104
`
`S
`
`S S TRN
`
`Rate signal R2
`
`E
`
`B1
`
`Data
`
`16T
`
`(Note)
`
`106
`
`Unclamp 104
`
`(Note)
`
`128T
`
`64T MT
`
`16T
`
`16T
`
`128T
`
`AC
`
`CA
`
`AC
`
`S S TRN
`
`R1
`
`S S TRN
`
`R3
`
`E
`
`B1
`
`Data
`
`106
`
`64T ± 2T
`Clamp 104
`
`A 2ETRAININITIATEDBYTHECALLINGMODEM
`
`16T
`
`256T
`
`1280T
`
`256T
`
`1280T
`
`8T
`
`106
`
`Unclamp 104
`
`128T
`
`64T ± 2T
`
`NT
`
`256T
`
`1280T
`
`8T 128T
`
`Call
`mode
`modem
`
`Data
`
`Answer
`mode
`modem
`
`Data
`
`CC
`
`NT
`
`AA
`
`106
`
`Clamp
`104
`
`S
`
`S S TRN
`
`Rate signal R2
`
`E
`
`B1
`
`Data
`
`16T
`
`(Note)
`
`106
`
`Unclamp 104
`
`(Note)
`
`64T
`
`MT
`
`16T
`
`16T
`
`128T
`
`AC
`
`CA
`
`AC
`
`S S TRN
`
`R1
`
`S S TRN
`
`R3
`
`E
`
`B1
`
`Data
`
`106
`
`64T ± 2T
`Clamp 104
`
`16T
`
`256T
`
`1280T
`
`256T
`
` ‡
`
`1280T
`
`8T
`
`B 2ETRAININITIATEDBYTHEANSWERINGMODEM
`
`106
`
`Unclamp 104
`
`T1701540-92/d05
`
`Signal states ACAC..AC for an even number of symbol intervals T; similarly with CA, AA and CC.
`Round-trip delays observed from answer and call modems respectively, including 64T ± 2T symbol intervals modem turn round delay.
`Signal states ABAB..AB, CDCD..CD.
`Scrambled ones at 4800 bit/s with dibits encoded directly to states A, B, C and D as defined in 5.2.3.
`Each a repeated 16-bit rate sequence at 4800 bit/s scrambled and differentially encoded as in Table 1.
`A single 16-bit sequence marking and following the end of a whole number of 16-bit rate sequences in R2 and R3.
`Binary ones scrambled and encoded as for the subsequent transmission of data.
`
`AC
`MT, NT
`S, S
`TRN
`R1, R2, R3
`
`EB
`
`1
`
`NOTE – The inclusion of a special echo canceller training sequence at this point is optional (see 5.4, Note 3).
`
`FIGURE 5/V.32
`
`FIGURE 5/V.32...[D05] = 24.5 CM PAGE PLEINE
`
`Recommendation V.32 (03/93)
`
`11
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 15 of 27
`
`‡
`‡
`‡
`‡
`‡
`‡
`‡
`‡
`‡
`

`

`TABLE 5/V.32
`
`Encoding for TRN segment after the first 256 symbols
`
`Dibit
`
`00
`01
`11
`10
`
`Signal state
`
`A
`B
`C
`D
`
`NOTE – Signal states A, B, C and D are shown in Figure 1.
`
`TABLE 6/V.32
`
`Coding of the 16-bit rate sequence
`
`B0
`B0
`
`B1
`B0
`
`B2
`B0
`
`B3
`B0
`
`B4
`–
`
`B5
`–
`
`B6
`–
`
`B7
`B1
`
`B8
`–
`
`B9
`–
`
`10
`–
`
`11
`11
`
`12
`–
`
`13
`–
`
`14
`–
`
`15
`11
`
`B0
`B0
`
`B1
`B0
`
`B2
`B0
`
`B3
`B0
`
`B4
`–
`
`etc.
`
`B0-3, B7, 11, 15
`B4
`B5
`B6
`B4-6
`B8
`
`B9-14
`
`For synchronizing on a received rate signal
`1 denotes ability to receive data at 2400 bit/s (see Note 1)
`1 denotes ability to receive data at 4800 bit/s
`1 denotes ability to receive data at 9600 bit/s
`0 0 0 calls for a GSTN cleardown
`1 denotes availability of trellis coding/decoding at the highest data rate indicated in B4-6 (see
`Note 1)
`0 0 1 0 0 0 denotes absence of special operational modes (see Note 2)
`
`NOTES
`1 The combination of B4 equal one and B8 equal one indicates V.32 bis operation.
`2 The use of bits B9, 10 and 12 through 14 is defined in Recommendation V.32 bis for data signalling rates other than 4800
`and 9600 bit/s.
`
`TABLE 7/V.32
`
`Coding of signal E
`
`B0
`B1
`
`B1
`B1
`
`B2
`B1
`
`B3
`B1
`
`B4
`–
`
`B5
`–
`
`B6
`–
`
`B7
`B1
`
`B8
`–
`
`B9
`–
`
`10
`–
`
`11
`11
`
`12
`–
`
`13
`–
`
`14
`–
`
`15
`11
`
`B4-14
`
`As in Table 6, except that the only data rate and coding to be indicated shall relate
`to the transmission of scrambled binary ones immediately following signal E
`
`12
`
`Recommendation V.32 (03/93)
`
`CommScope, Inc.
`IPR2023-00066, Ex. 1016
`Page 16 of 27
`
`

`

`5.4
`
`Start-up procedure
`
`The procedure for achieving synchronism between the calling modem and the answering modem on international GSTN
`connections is shown in Figure 4. The procedure includes the estimating of round-trip delay from each modem, the
`training of echo cancellers and receivers initially with half-duplex transmissions, and the exchanging of rate signals for
`automatic bit-rate and mode selection.
`
`5.4.1
`
`Call mode modem
`
`After receiving the answer tone for a period of at least 1 s as specified in Recommendation V.25, the modem shall be
`connected to line (see Note 1 in 5.4.2) and shall condition the scrambler and descrambler in accordance with 4.1.
`
`The modem shall repetitively transmit carrier state A as shown in Figure 1.
`
`The modem shall be conditioned to detect (see Note 2 in 5.4.2) one of two incoming tones at frequencies 600 –
`3000 –
` 7 Hz, and subsequently to detect a phase reversal in that tone.
`
` 7 Hz and
`
`On detection of one such phase reversal, the modem shall be conditioned to detect a second phase reversal in the same
`tone, start a counter/timer and change to repetitively transmitting state C as shown in Figure 1. The time delay between
`the reception of this phase reversal at the line terminals and the transmitted AA to CC transition appearing at the line
`terminals shall be 64 –
` 2 symbol periods.
`
`On detection of a second phase reversal in the same incoming tone, the modem shall stop the counter/timer and cease
`transmitting.
`
`When the modem detects an incoming S sequence (see 5.2), it shall proceed to train its receiver, and then seek to detect
`at least two consecutive identical 16-bit rate sequences as defined in Table 6.
`
`On detection of the rate signal (R1), the modem shall transmit an S sequence for a period NT already estimated by the
`counter/timer.
`
`After this period has expired (see Note 3 in 5.4.2), the modem shall transmit the receiver conditioning signal as defined
`in 5.2, starting with an S sequence for 256 symbol intervals.
`
`Transmission of the TRN segment of the receiver conditioning signal may be extended in order to ensure a satisfactory
`level of echo cancellation (see Note 4 in 5.4.2).
`
`After the TRN segment, the modem shall apply an ON condition to circuit 107 and transmit a rate signal (R2) in
`accordance with 5.3 to indicate the currently available data rates and