ETSI ETS 300 116 ed.2 (1996-05)

Public Switched Telephone Network (PSTN); Category II specification for 1 200 bits per second duplex modems standardized for use on the PSTN

RE/TE-05047

Priključitve na javno komutirano telefonsko omrežje (PSTN) – Priključitvene zahteve kategorije II za dupleksne modeme za hitrosti 1200 b/s, standardizirane za uporabo v PSTN

General Information

• Status: Published
• Publication Date: 29-May-1996
• Technical Committee: TE 5 - General Terminal Access Requirements
• Current Stage: 12 - Completion
• Due Date: 21-May-1996
• Completion Date: 30-May-1996
• Ref Project: SIST ETS 300 116 E2:2003 - Public Switched Telephone Network (PSTN); Category II specification for 1 200 bits per second duplex modems standardized for use on the PSTN

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ETS 300 116 E2:2003
01-december-2003
3ULNOMXþLWYHQDMDYQRNRPXWLUDQRWHOHIRQVNRRPUHåMH3671±3ULNOMXþLWYHQH
]DKWHYHNDWHJRULMH,,]DGXSOHNVQHPRGHPH]DKLWURVWLEVVWDQGDUGL]LUDQH]D
XSRUDERY3671
Public Switched Telephone Network (PSTN); Category II specification for 1 200 bits per
second duplex modems standardized for use on the PSTN
Ta slovenski standard je istoveten z: ETS 300 116 Edition 2
ICS:
33.040.35 Telefonska omrežja Telephone networks
SIST ETS 300 116 E2:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 116 E2:2003

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SIST ETS 300 116 E2:2003
EUROPEAN ETS 300 116
TELECOMMUNICATION May 1996
STANDARD Second Edition
Source:ETSI TC-TE Reference:RE/TE-05047
ICS: 33.020
modems, PSTN, testing
Key words:
Public Switched Telephone Network (PSTN);
Category II specification for 1 200 bits per
second duplex modems standardized for use on the PSTN
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - [e-mail]
X.400: Internet:
Tel.: [phone] - Fax: [phone]
*
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1996. All rights reserved.

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ETS 300 116: May 1996
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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ETS 300 116: May 1996
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .8
3.1 Definitions .8
3.2 Abbreviations .8
4 General requirements .8
4.1 References to other ETSs .8
4.2 Information to be provided by the applicant.8
4.2.1 Information required for testing purposes .8
4.2.2 Instructions for use.9
5 Functional requirements specific to category II modems.9
5.1 General requirements .9
5.2 Modes .10
5.3 Line signals.10
5.3.1 Carrier frequencies.10
5.3.2 Guard tone .11
5.3.2.1 Guard tone - call mode modem.11
5.3.2.2 Guard tone - answer mode modem.11
5.3.3 Transmitted spectrum .11
5.4 Line signalling rates .11
5.5 Encoding and decoding of data .11
5.6 Threshold of received line signal detection.12
5.7 Channel allocation .12
5.7.1 Channel selection.12
5.7.2 Automatic channel selection.12
5.8 Hand-shaking sequences .12
5.8.1 Auto-calling and auto-answering procedures.12
5.8.1.1 Auto-calling - calling tone.12
5.8.1.2 Auto-calling - recognition of answering tone.12
5.8.1.3 Auto-answering.13
5.8.2 Start-up procedures.13
5.8.2.1 Call Mode Modem.13
5.8.2.2 Answer Mode Modem.13
5.9 Transmission of start-stop characters .14
5.10 Scrambler and descrambler.14
5.11 Test loop 2 .14
5.11.1 Instigation of a remote loop 2.15
5.11.2 Termination of a remote loop 2 .15
5.12 Receiver performance .15
Annex A (normative): Testing methods.16
A.1 General testing conditions.16
A.1.1 General notes .16
A.1.2 Proposed order for performing the tests.16
A.1.3 Limitation of number of tests.17
A.1.3.1 Introduction.17
A.1.3.2 General rules.17
A.1.3.3 Specific rules.18

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ETS 300 116: May 1996
A.2 Test for subclause 5.3.1 (carrier frequencies). 18
A.2.1 Test for subclause 5.3.1 using the MCT . 18
A.2.2 Test for modems where the scrambler can be inhibited . 18
A.2.3 Tests for modems where test points are accessible. 19
A.2.4 Test for modems where neither subclause A.2.2 nor subclause A.2.3 applies . 19
A.3 Test for subclause 5.3.2 (guard tone). 19
A.3.1 Test for subclause 5.3.2.1 (guard tone, call mode modem) . 19
A.3.2 Test for subclause 5.3.2.2 (guard tone, answer mode modem) . 19
A.4 Test for subclause 5.4 (line signalling rates) . 20
A.5 Test for subclause 5.5 (encoding and decoding of data). 20
A.6 Test for subclause 5.6 (threshold of received line signal detection). 20
A.7 Test for subclause 5.7 (channel allocation). 20
A.7.1 Test for subclause 5.7.1 (general) . 21
A.7.2 Test for subclause 5.7.2 (automatic channel selection). 21
A.8 Test for subclause 5.8 (hand-shaking sequences). 21
A.8.1 Call mode modem (CMM). 21
A.8.2 Answer Mode Modem (AMM) . 22
A.9 Test for subclause 5.10 (scrambler and descrambler). 23
A.9.1 Test for modems which can be operated in the synchronous mode of use. 23
A.9.2 Test for modems which can only be operated in a asynchronous mode of use . 23
A.10 Test for subclause 5.11 (test loop 2) . 24
A.10.1 Instigation of remote test loop 2 . 24
A.10.1.1 Transmission of the test loop initiation signal (controlling modem under
test). 24
A.10.1.2 Response to the test loop initiation signal (controlled modem under test) . 24
A.10.2 Deactivation of remote test loop 2. 25
A.10.2.1 Transmission of the deactivation signal(controlling modem under test). 25
A.10.2.2 Response to the deactivation signal (controlled modem under test). 25
Annex B (normative): Derivation of timings . 26
Annex C (informative): Example proforma for the declaration of modes of operation/use. 27
Annex D (informative): Bibliography . 29
History. 30

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ETS 300 116: May 1996
Foreword
This second edition European Telecommunication Standard (ETS) has been produced by the Terminal
Equipment (TE) Technical Committee of the European Telecommunications Standards Institute (ETSI).
The objective of this specification, the application of which is entirely voluntary, is to provide the users with
an added degree of assurance that modems in compliance with this specification can interwork with each
other, under most network conditions.
This ETS contains the technical characteristics required for end-to-end interworking over the Public
Switched Telephone Network (PSTN) for 1 200 bits per second duplex modems standardized for use over
the PSTN.
These requirements are based on, and do not conflict with, CCITT Recommendation V.22 [1]. Additional
requirements are included relating to end-to-end inter-operability over PSTN connections. Such
requirements are in excess of the CCITT/ITU-T Recommendations.
Except where otherwise indicated, a modem which complies with CCITT Recommendation V.22 [1]
should always meet the requirements of this ETS which relate to parameters specified in that CCITT
Recommendation.
Clause 4 of this ETS references the requirements which are common to both Category I and Category II
modems, which are contained in clause 4 of final draft prETS 300 114 [2]. The definition of Category I and
Category II modems can be found in the foreword of final draft prETS 300 114 [2].
Clause 5 of this ETS contains Category II requirements specific to 1 200 bits per second duplex modems.
In the case of certain functions common to a number of different types of modem (e.g. auto-answering
sequence) reference is made to clause 5 of final draft prETS 300 114 [2] which contains the relevant
requirements.
Transposition dates
Date of adoption of this ETS: 26 April 1996
Date of latest announcement of this ETS (doa): 31 August 1996
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 29 February 1997
Date of withdrawal of any conflicting National Standard (dow): 29 February 1997

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1 Scope
This ETS contains the technical characteristics required for end-to-end interworking over the Public
Switched Telephone Network (PSTN) of 1 200 bits per second (bit/s) duplex modems standardized for
use over the in accordance with CCITT Recommendation V.22 [1].
NOTE: CCITT Recommendation V.22 [1] also describes a method of transmitting data at
600 bit/s. This ETS specifies the characteristics to be met by such modems and, if
requested by the applicant, this feature can also be tested against the specifications.
The term "modem" in the context of this ETS includes all physical implementation practices for a voice
band modem which is conductively connected to the PSTN.
This ETS specifies four modes of operation each with up to five modes of use (see subclause 5.2).
This ETS also contains descriptions of the tests to be performed in order to confirm compliance with the
functional requirements contained herein. A general description of the test conditions and test
requirements is given in annex A (normative).
2 Normative references
This ETS incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to, or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references the latest
edition of the publication referred to applies.
[1] CCITT Recommendation V.22 (1984): "1 200 bits per second duplex modem
standardized for use in the general switched telephone network and on
point-to-point 2-wire leased telephone-type circuits".
[2] Final draft prETS 300 114 (1996): "Public Switched Telephone Network (PSTN);
Basic Category I and Category II specifications for modems standardized for
use on the PSTN".
[3] ETS 300 001: "Attachments to the Public Switched Telephone Network (PSTN);
General technical requirements for equipment connected to an analogue
subscriber interface in the PSTN".
[4] CCITT Recommendation V.25 (1984): "Automatic answering equipment and/or
parallel automatic calling equipment on the general switched telephone network
including procedures for disabling of echo control devices for both manually and
automatically established calls".
[5] CCITT Recommendation S.33 (1984): "Standardization of an international text
for the measurement of the margin of start-stop machines using International
Alphabet No 5".
[6] CCITT Recommendation V.52 (1984): "Characteristics of distortion and error-
rate measuring apparatus for data transmission".

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3 Definitions and abbreviations
3.1 Definitions
For the purposes of this ETS, the definitions of final draft prETS 300 114 [2] apply, together with the
following:
Modem Conformance Tester (MCT): Essentially a modem to the same recommendation as the modem
under test, but the individual sub-systems within it are both accessible (e.g. provide test points and permit
functions to be enabled or disabled when required) and externally controllable (e.g. permit sequences
such as the start up procedure to be selectively repeated). The sub-systems within a conformance tester
may be constructed as discrete items of equipment, so as to permit their assembly into varying
configurations required to suit the tests (e.g. the asynchronous to synchronous converter may be simply
applied to a synchronous CCITT Recommendation V.22 [1] conformance tester to achieve an
asynchronous V.22 conformance tester).
As an interim measure, until the conformance tester is defined, its definition agreed to be appropriate by
ETSI, and such a tester is available, a modem used for reference may be used in its place. In the case
that the modem used for reference has not been shown to conform to the ETS in the relevant modes of
operation/use, the testing authority ensures that the modem used for reference complies with the relevant
ETS to the extent necessary for the performance of the test.
silence: Periods during the hand-shaking sequences where signals are not transmitted.
The period of silence is measured using the start and finish criteria defined below. The levels refer to
signals which in the relevant frequency band have an in-band power level and are expressed with respect
to the normal transmitted signal level of the modem under test recorded at the point of observation.
start of the period of silence: The instant at which the transmitted signal level drops below a level that is
6 dB below the normal transmit level.
end of period of silence: The instant the transmitted signal rises above a level that is 6 dB below the
normal transmit level. During the period of silence at least one instant is observed where the signal level is
at least 30 dB below the normal transmit level.
3.2 Abbreviations
For the purposes of this ETS, the abbreviations given in final draft prETS 300 114 [2] apply.
4 General requirements
4.1 References to other ETSs
The modem shall comply with final draft prETS 300 114 [2], clause 4.
NOTE: Final draft prETS 300 114 [2] in turn refers to ETS 300 001 [3] for the majority, if not
all, of its requirements.
4.2 Information to be provided by the applicant
4.2.1 Information required for testing purposes
The applicant shall declare for which of the modes of operation/use identified in this ETS, the modem is
supposed to undergo tests.
Compliance shall be considered to have been accomplished by provision of the relevant information.
NOTE: This could be accomplished by completion of forms such as those provided in
annex C.

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4.2.2 Instructions for use
Instructions for use shall be made available with the apparatus. The instructions for use shall include:
a) the apparatus or types of apparatus to which the instructions apply;
b) any information specifically indicated in this ETS for inclusion in the "Instructions for use";
and
c) any national restrictions on the use of the apparatus.
Any additional information that has been included shall be disregarded unless it is the subject of another
ETS.
Compliance shall be checked by inspection.
5 Functional requirements specific to category II modems
5.1 General requirements
To comply with the requirements of this ETS, the modem shall provide:
- duplex mode of operation with continuous carrier, by means of the modulation scheme specified in
CCITT Recommendation V.22 [1];
- channel separation by frequency division;
- means by which the channels may be selected either manually and/or automatically, where a
modem is capable of transmitting in either of the two channels;
- provision of a guard tone of 1 800 Hz ± 20 Hz, which a modem is to transmit while transmitting in
the high channel;
- signalling rates of 1 200 bit/s and, optionally, 600 bit/s;
- the interchange circuits (or equivalent) that are required to change state after an identifiable event
or point in time, shall have changed state within a maximum of 3 seconds of that event, unless
otherwise specified (see note 4).
NOTE 1: The general requirements described above are a subset of CCITT Recommendation
V.22 [1]. In the requirements which follow, any deviations from the strict interpretation
of the Recommendation have been identified.
NOTE 2: In the following, references are made to interchange circuits between the modem and
the Data Terminal Equipment (DTE), as defined in CCITT Recommendation V.24.
However, not all modems provide an interface with such interchange circuits. For
these cases the references to CCITT Recommendation V.24 type interchange circuits
indicate equivalent functionality of a DTE and a modem.
NOTE 3: To perform certain tests specified herein, it is desirable that it be possible to disable
the transmit scrambler of the modem.
NOTE 4: This requirement is in addition to CCITT Recommendation V.22 [1].

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5.2 Modes
It shall be possible to configure the modem to operate in at least one of the following modes of operation:
- 1 200 bit/s call mode;
- 1 200 bit/s answer mode;
and, optionally, in one or both of the following modes of operation:
- 600 bit/s call mode;
- 600 bit/s answer mode.
For each of the modes of operation at least one of the following modes of use shall be provided:
a) asynchronous with 8 bits per character;
b) asynchronous with 9 bits per character;
c) asynchronous with 10 bits per character;
d) asynchronous with 11 bits per character;
e) synchronous.
NOTE: It is acceptable for the same mode of use to be provided for each of the modes of
operation selected.
In the asynchronous (start-stop) modes of operation, the modem shall accept a data stream from the DTE
at a nominal rate of 1 200 bits per second or, optionally, 600 bits per second. The asynchronous data to
be transmitted shall, in accordance with subclause 5.9, be converted into a synchronous data stream
suitable for transmission.
Demodulated data shall be decoded in accordance with subclause 5.5, then descrambled in accordance
with subclause 5.10 and it shall then be passed for re-conversion into an asynchronous data stream in
accordance with subclause 5.9.
In the synchronous mode of operation, the modem shall accept synchronous data from the DTE. The data
shall then be scrambled in accordance with subclause 5.10 and passed to the modulator for encoding in
accordance with subclause 5.5.
Demodulated data shall be decoded in accordance with subclause 5.5, then descrambled in accordance
with subclause 5.10.
It shall be the applicant's responsibility to specify for which of these modes of operation/use the modem is
supposed to undergo tests.
5.3 Line signals
5.3.1 Carrier frequencies
The carrier frequencies shall be 1 200 Hz ± 0,5 Hz for the low channel and 2 400 Hz ± 1 Hz for the high
channel.
Compliance shall be checked by the method described in annex A, clause A.2.

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5.3.2 Guard tone
5.3.2.1 Guard tone - call mode modem
When the modem is transmitting in the low channel, it shall not transmit the guard tone specified in
subclause 5.3.2.2.
Compliance shall be checked by the method described in annex A, subclause A.3.1.
5.3.2.2 Guard tone - answer mode modem
When the modem is transmitting in the high channel, a guard tone at 1 800 Hz ± 20 Hz shall be
transmitted simultaneously. The level of the guard tone shall be 6 dB ± 1 dB below the level of the data
signal in the high channel.
Optionally, facilities may be provided to disable the transmission of the guard tone of 1 800 Hz. Since the
provision of the guard tone is mandatory, all tests in this ETS shall be carried out with guard tone present.
Compliance shall be checked by the method described in annex A, subclause A.3.2.
The overall level of the guard tone and the data signal of a CCITT Recommendation V.22 [1] modem shall
remain in compliance with the in-band spectral power limits for the network to which they are being
connected (see final draft prETS 300 114 [2], clause 4).
NOTE: The purpose of the guard tone is to inhibit the false operation of in-band signalling
systems such as in international networks (see CCITT Recommendation Q.144). It is
thought by some that a marginal performance advantage may be gained as a result of
the slightly higher transmit level possible when the guard tone is disabled and therefore
this option is permitted.
5.3.3 Transmitted spectrum
The national network specific spectral power limits are specified in final draft prETS 300 114 [2], clause 4.
NOTE: Final draft prETS 300 114 [2], clause 4 in turn refers to ETS 300 001 [3]. There are no
requirements in this ETS relating to the spectrum of signals presented to the PSTN
over and above those for PSTN access invoked by subclause 4.1.
5.4 Line signalling rates
The signalling rates transmitted to line shall be 1 200 bit/s ± 0,01 % and, if requested by the applicant,
600 bit/s ± 0,01 %.
Compliance shall be checked by the method described in annex A, clause A.4.
5.5 Encoding and decoding of data
The encoding and decoding of data shall be in accordance with CCITT Recommendation V.22 [1],
section 2.5.2 and table 1/V.22.
Until a Modem Conformance Tester (MCT) is available, compliance shall be checked by inspection of the
applicant's declaration of conformance. When an MCT is available, compliance shall be checked by the
method described in annex A, clause A.5.

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5.6 Threshold of received line signal detection
The modem shall comply with the requirements of final draft prETS 300 114 [2], subclause 5.4, when
receiving a data signal corresponding to scrambled binary 1 at 1 200 bit/s in the respective receive
channel for the modem.
Compliance shall be checked by the method described in annex A, clause A.6.
5.7 Channel allocation
A Call Mode Modem (CMM) shall be capable of transmitting signals in the low channel and responding to
signals received in the high channel. An Answer Mode Modem (AMM) shall be capable of transmitting
signals in the high channel and responding to signals received in the low channel.
5.7.1 Channel selection
A modem which is capable of being configured as both a CMM and an AMM shall provide facilities for at
least one of the following techniques of channel selection:
a) manual selection of the channels using facilities provided on the modem;
b) selection of the channels by the DTE (equivalent: CcT 126 control);
c) automatic selection of the channels as described in subclause 5.7.2.
NOTE: Other means of channel selection may also be provided but verification of the correct
functioning of such facilities is not a requirement of this ETS.
For techniques a) and b), compliance shall be checked by the method described in annex A,
subclause A.7.1.
5.7.2 Automatic channel selection
A modem providing this facility shall, in the absence of manual intervention or a contrary command via a
digital interface (e.g. an equivalent to control using CcT 126), be automatically configured as:
a) a CMM when exchanging data on-line to another compatible modem, and when the modem has
entered the on-line state other than in response to an incoming PSTN call;
b) an AMM when exchanging data on-line to another compatible modem, and when the modem has
entered the on-line state in response to an incoming PSTN call.
Compliance shall be checked by the method described in annex A, subclause A.7.2.
5.8 Hand-shaking sequences
In the following sequences the signal described shall be sent continuously unless the description indicates
that a period of silence be present.
5.8.1 Auto-calling and auto-answering procedures
5.8.1.1 Auto-calling - calling tone
This ETS shall not require the provision of the calling tone defined in CCITT Recommendation V.25 [4].
5.8.1.2 Auto-calling - recognition of answering tone
For modems to be used for automatically originated calls, the modem, or its associated call establishment
equipment, shall comply with the requirements for answering tone detection given in final draft
prETS 300 114 [2], subclause 5.2.1.

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