SIST I-ETS 300 245-1 E2:2003

• Abstract:

  To prepare an amendment sheet to, or a new edition of I-ETS 300 245-1 as a part of restructuring of the ISDN telephony terminal standards with the objective to make the structure easier to understand for the users.

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.080 - Integrated Services Digital Network (ISDN)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Ref Project: ETSI I-ETS 300 245-1 ed.2 (1996-02) - Integrated Services Digital Network (ISDN); Technical characteristics of telephony terminals; Part 1: General

SIST I-ETS 300 245-1 E2:2003 is the Slovenian standard identical to ETSI I-ETS 300 245-1 Edition 2, Part 1: General. It sets the general technical characteristics for Integrated Services Digital Network (ISDN) telephony terminals at the basic access coincident S and T reference point, covering electrical, logical and acoustic behaviour for telephony 3,1 kHz and telephony 7 kHz use. It is written for telephony terminals and for the telephony functions of multimedia or multiservice terminals.

What does SIST I-ETS 300 245-1 E2:2003 specify?

SIST I-ETS 300 245-1 E2:2003 specifies common requirements for telephony terminals connected to an ISDN basic access point. The document makes clear that these characteristics are additional to other attachment requirements for Terminal Equipment (TE), and that the standard is not intended for type approval or other mandatory requirements.

The document is organized into clauses 1 to 8 and two annexes. Clauses 4 to 8 cover access channel selection, call control, transmission aspects, power feeding, and physical modules. Annex A gives the test specifications, and Annex B gives the bibliography.

Annex	What it covers
Annex A (normative)	Test conditions, equipment interface, calibration, DTMF measurements, and audible alerting module measurements
Annex B (informative)	Bibliography and related documents

The scope also points readers to other parts of the series for speech coding algorithms and specific terminal functions. That matters in practice because a terminal may need more than Part 1 when it uses wideband speech, additional equipment, or locally generated tones.

What are the key requirements of SIST I-ETS 300 245-1 E2:2003?

Clause 4 requires a terminal to work through any B-channel, and its behaviour must not depend on which B-channel is chosen. In practice, this means the terminal should not need special handling for one channel over another.

Outgoing calls

Clause 5.1 requires the normal call-control procedures for both en-bloc and overlap sending. For telephony 3,1 kHz and telephony 7 kHz, the terminal must code the Bearer capability information element correctly, and it must handle fall-back for 7 kHz calls when that option is allowed. This matters because the network and the called terminal use these fields to decide whether the call can proceed and what service will result.

Clause 5.1 also requires the High layer compatibility (HLC) information element for telephony calls, and it places conditions on the Low layer compatibility (LLC) information element and the Called party number information element. The practical effect is that the terminal must present call setup information in a way that avoids compatibility problems with other terminal types.

Incoming calls and compatibility

Clause 5.2 defines how incoming calls are checked for compatibility. The terminal analyses Bearer capability and HLC information, ignores LLC for this purpose, and can use Multiple Subscriber Number (MSN) and Subaddressing (SUB) for terminal selection. In practice, this is what lets the right terminal answer and lets the wrong call be rejected or ignored.

Clause 5.2 also covers restricted power conditions and the designated terminal. A designated terminal under restricted power must still respond to permitted incoming calls, which matters when the terminal must keep basic speech service alive during limited power supply conditions.

Information tones and DTMF

Clause 5.3 requires the terminal to pass network tones and announcements to the user, and it allows local generation of tones or announcements based on local information or D-channel messages. That means the user can still receive audible guidance even when the network does not supply it on the B-channel.

Clause 5.4 makes DTMF signalling optional, but if implemented it must use the defined frequency pairings, levels and timing, and it must not be connected to the B-channel before the call state allows it. This is important for services that use keypad signalling during a call.

Transmission and power feeding

Clause 6 states that the default speech encoding algorithm is G.711 A-law at 64 kbit/s. That gives a clear baseline for interoperability, while allowing other codings only as additional options.

Clause 7 ties the terminal to the power-feeding requirements in TBR 3 and defines conditions for restricted power operation, leakage current, and designation visibility. In practice, this affects terminals that must continue operating from limited network power and must show the user whether they are designated for that mode.

Physical modules

Clause 8 requires an alerting module and defines its acoustic behaviour and control timing. The audible alerting module must meet sound level and frequency-spectrum requirements, and it must start and stop within specified times after call-control messages. That matters for ringing audibility, user reaction time, and consistent behaviour across terminals.

What terms does SIST I-ETS 300 245-1 E2:2003 define?

• Designated terminal - A terminal allowed to draw power from Power Source 1 under restricted power conditions.
• Digital interface - The B-channels available at the coincident S and T reference point of an ISDN basic access.
• Restricted power condition - The power-limited state described in I.430, indicated by reversed phantom-voltage polarity.
• Telephony terminal - A terminal that supports telephony 3,1 kHz teleservice and/or telephony 7 kHz teleservice.
• Telephony 3,1 kHz teleservice - A bidirectional speech service that uses a B-channel for user information and a D-channel for signalling.
• Telephony 7 kHz teleservice - A real-time service for exchanging speech over one circuit-mode 64 kbit/s connection.
• Dual Tone Multi Frequency (DTMF) - The push-button signalling method that uses two simultaneous tones per digit.

Who uses SIST I-ETS 300 245-1 E2:2003?

Manufacturers of ISDN telephony terminals use this standard when designing set-up behaviour, compatibility handling, alerting, DTMF signalling, and power-feeding behaviour. Test laboratories use it together with Annex A to verify acoustic and signalling performance.

Quality managers and buyers use it to check whether a terminal is meant for basic-access ISDN telephony, including telephony 3,1 kHz and telephony 7 kHz functions. Network and terminal engineers use it to align terminal behaviour with call-control procedures, compatibility checks, and fallback handling. It is also relevant for multimedia and multiservice terminal developers when telephony functions are included.

Which standards are used with SIST I-ETS 300 245-1 E2:2003?

The foreword places this part in an eight-part series: Part 2 on PCM A-law handset telephony, Part 3 on PCM A-law loudspeaking and hands free telephony, Part 4 on additional equipment, Part 5 on wideband 7 kHz handset telephony, Part 6 on wideband 7 kHz loudspeaking and hands free telephony, Part 7 on locally generated information tones, and Part 8 on LD-CELP speech transmission at 16 kbit/s.

Standard	What it contributes
ETS 300 102-1	Basic call control, bearer capability coding, and call clearing procedures
ETS 300 267-1	7 kHz teleservice signalling and resultant-service handling
I-ETS 300 322	Test suite used for several compatibility checks
ETS 300 104	Layer 3 attachment testing for basic access
TBR 3	Attachment requirements and power-feeding requirements
CCITT Recommendation I.430	Layer 1 and restricted power condition definitions
CCITT Recommendation I.411	Reference configurations for ISDN user-network interfaces
CCITT Recommendation G.711	Default A-law speech coding
CCITT Recommendation G.722	7 kHz audio coding
CCITT Recommendation E.164	Numbering and selection by ISDN number
CCITT Recommendation G.101	Transmission plan and 0 dBr reference
IEC Publication 651	Sound level meter requirements for alerting measurements

What does the SIST I-ETS 300 245-1 E2:2003 document contain?

The document contains call-control procedures for outgoing and incoming calls, including Bearer capability, HLC and LLC handling, terminal selection, and resultant-service indication. It also contains requirements for tones, DTMF signalling, call clearing, transmission encoding, power feeding, and alerting modules.

Annex A gives the test environment, test-equipment interface, calibration accuracy, alternative test methods, DTMF measurement methods, and the acoustic measurement method for the alerting module. It also supports the measurement of tone frequency, level, timing, and sound pressure in a controlled setup. Figure 1 presents the DTMF signalling scheme used by the standard.

SLOVENSKI STANDARD
01-december-2003
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WHOHIRQVNLKWHUPLQDORY±GHO6SORãQR
Integrated Services Digital Network (ISDN); Technical characteristics of telephony
terminals; Part 1: General
Ta slovenski standard je istoveten z: I-ETS 300 245-1 Edition 2
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERIM
EUROPEAN I-ETS 300 245-1
TELECOMMUNICATION February 1996
STANDARD Second Edition
Source: ETSI TC-TE Reference: RI/TE-04040
ICS: 33.080
ISDN, telephony terminals
Key words:
Integrated Services Digital Network (ISDN);
Technical characteristics of telephony terminals;
Part 1: General
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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I-ETS 300 245-1: February 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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I-ETS 300 245-1: February 1996
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .8
3.1 Definitions .8
3.2 Abbreviations .9
4 Access channel selection.9
5 Call control functions.9
5.1 Outgoing calls .9
5.1.1 Coding of Bearer capability information element.9
5.1.1.1 Telephony 3,1 kHz teleservice.10
5.1.1.2 Telephony 7 kHz teleservice.10
5.1.1.3 Interim solution before the introduction of telephony 7 kHz
teleservice (optional).10
5.1.1.4 Other services .10
5.1.2 Coding of High layer compatibility information element .11
5.1.3 Coding of Low layer compatibility information element .11
5.1.4 Coding of Called party number information element.11
5.1.5 Indication of resultant service.11
5.2 Incoming calls .12
5.2.1 Compatibility checking.12
5.2.1.1 Analysis of Bearer capability information element.12
5.2.1.2 Analysis of High layer compatibility information element.13
5.2.1.3 Analysis of Low layer compatibility information element.13
5.2.1.4 Terminal selection .13
5.2.2 Compatibility checking for the designated terminal under restricted power
condition .14
5.2.3 Incoming call indication .14
5.2.3.1 Terminal is free to accept an incoming call .14
5.2.3.2 Terminal is busy.14
5.2.4 Response to incoming calls.14
5.3 Information tones .15
5.3.1 Transmission of tones and announcements from the network .15
5.3.2 Generation of tones by the terminal .15
5.4 DTMF signalling.16
5.4.1 General.16
5.4.2 Connection to B-channel .16
5.4.3 Signalling frequencies .16
5.4.4 Frequency deviation .16
5.4.5 Level.16
5.4.6 Timing.17
5.5 Call clearing .17
6 Transmission aspects .17
6.1 Encoding.17
6.2 Relative level.17
7 Power feeding .17
7.1 General conditions.17
7.2 Restricted power condition.17
7.3 Leakage current.17
7.4 Operation of the designated terminal under restricted power conditions.17

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I-ETS 300 245-1: February 1996
7.5 Method of designation. 18
7.6 Visibility of designation . 18
8 Physical modules. 18
8.1 Handset. 18
8.2 Alerting module . 18
8.2.1 Audible alerting module . 18
8.2.1.1 Sound pressure level . 18
8.2.1.2 Frequency spectrum . 18
8.2.2 Alerting module control. 19
8.2.2.1 Starting. 19
8.2.2.2 Stopping. 19
Annex A (normative): Test specifications . 20
A.1 General conditions for testing. 20
A.1.1 Environment for test . 20
A.1.2 Test equipment interface. 20
A.1.3 Test equipment requirements . 20
A.1.3.1 Electro-acoustic equipment . 20
A.1.4 Alternative test methods. 20
A.1.5 Accuracy of calibration . 20
A.1.6 Bandwidth. 21
A.2 DTMF measurements. 21
A.2.1 Frequency deviation . 21
A.2.2 Signal level . 21
A.2.3 Signal timing. 21
A.3 Audible alerting module . 21
A.3.1 Sound pressure level measurement . 21
A.3.1.1 Measurement conditions. 21
A.3.1.2 Measurement method. 21
Annex B (Informative): Bibliography . 23
History. 24

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I-ETS 300 245-1: February 1996
Foreword
This second edition of Part 1 of this Interim European Telecommunication Standard (I-ETS) was produced
by the Terminal Equipment (TE) Technical Committee of the European Telecommunications Standards
Institute (ETSI).
An ETSI standard may be given I-ETS status either because it is regarded as a provisional solution ahead
of a more advanced standard, or because it is immature and requires a "trial period". The life of an I-ETS
is limited to three years after which it can be converted into an ETS, have it's life extended for a further
two years, be replaced by a new version, or be withdrawn.
This second edition of Part 1 of this I-ETS is the first Part of an I-ETS comprising eight Parts.
Part 1: General.
Part 2: PCM A-law, handset telephony.
Part 3: PCM A-law, loudspeaking and hands free telephony.
Part 4: Interface for additional equipment.
Part 5: Wideband (7 kHz) handset telephony.
Part 6: Wideband (7 kHz), loudspeaking and hands free telephony.
Part 7: Locally generated information tones.
Part 8: Speech transmission characteristics when using Low-Delay Code-Excited Linear Prediction
(LD-CELP) coding at 16 kbit/s.
Proposed announcement date
Date of adoption of this I-ETS: 29 February 1996
Date of latest announcement of this I-ETS (doa): 31 May 1996

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I-ETS 300 245-1: February 1996
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I-ETS 300 245-1: February 1996
1 Scope
This second edition of Part 1 of this Interim European Telecommunication Standard (I-ETS) specifies the
technical characteristics (electrical, logical and acoustic) for telephony terminals to be used at the basic
access of the coincident S and T reference point of the Integrated Services Digital Network (ISDN). The
characteristics of this I-ETS are additional to any other Standard or attachment requirements to which the
Terminal Equipment (TE) is subject (note 1). The additional characteristics of this I-ETS are meant to give
improved performance relative to the attachment requirements. However, this I-ETS is not intended to be
used for type approval purposes or other mandatory requirements.
This I-ETS is applicable to telephony terminals as well as to telephony functions of multimedia or
multiservice terminals.
This I-ETS is applicable to TE of the functional group defined as Terminal Equipment Type 1 (TE1) in
CCITT Recommendation I.411 [1].
The characteristics specified in this I-ETS cover a number of functions or facilities which can be combined
to form a particular terminal. The characteristics relevant for each speech coding algorithm, function or
facility can be found in separate Parts of the I-ETS. This Part (Part 1) covers the introduction to the I-ETS
and the characteristics which are common to telephony terminals to be connected to a coincident S and T
reference point to a public telecommunication network presented as an ISDN basic access point.
For multimedia or multiservice terminals other requirements or standards may apply instead of, or in
addition to, this I-ETS.
TE specially designed for the disabled (e.g. with amplification of received speech as an aid for the
hard-of-hearing), may have characteristics which may be specified in separate Parts of this I-ETS.
TE using a radio link (e.g. cordless telephones) will, due to the characteristics of the radio channel, be
specified separately.
NOTE 1: Attachment requirements for ISDN telephony terminals can be found in TBR 3 and
TBR 8.
NOTE 2: In some countries, an interim ISDN service corresponding to, but not wholly compatible
with, the ISDN basic access standards may be provided. For connection to such a
service, this I-ETS is not applicable.
2 Normative references
This I-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 I-ETS only when incorporated in it by amendment or revision. For undated references the
latest edition of the publication referenced to applies.
[1] CCITT Recommendation I.411 (1988): "Integrated Services Digital Network
(ISDN) user-network interfaces - Reference configurations".
[2] CCITT Recommendation P.10 (1988): "Vocabulary of terms on telephone
transmission quality and telephone sets".
[3] CCITT Recommendation G.701 (1988): "Vocabulary of digital transmission and
multiplexing, and pulse code modulation (PCM) terms".
[4] CCITT Recommendation I.430 (1988): "Integrated Services Digital Network
(ISDN) user-network interfaces - layer 1 recommendations".
[5] ETS 300 102-1 (1990 including Amendment 1 (1993)): "Integrated Services
Digital Network (ISDN); User-network interface layer 3, Specification for basic
call control".
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I-ETS 300 245-1: February 1996
[6] ETS 300 104 (1991): "Integrated Services Digital Network (ISDN); Attachment
requirements for terminal equipment to connect to an ISDN using ISDN basic
access, Layer 3 aspects".
[7] ETS 300 267-1 (1994): "Integrated Services Digital Network (ISDN); Telephony
7 kHz and videotelephony teleservices; Digital Subscriber Signalling System No.
one DSS1) protocol; Part 1: Protocol specification".
[8] I-ETS 300 322 (1995): "Integrated Services Digital Network (ISDN); Digital
Subscriber Signalling System no one (DSS1); Abstract Test Suite (ATS)
specification for signalling network layer protocol for circuit mode basic call
control".
[9] CCITT Recommendation G.711 (1988): "Pulse code modulation (PCM) of voice
frequencies".
[10] CCITT Recommendation G.722 (1988): "7 kHz audio-coding within 64 kbit/s".
[11] CCITT Recommendation E.164 (1991): "Numbering plan for the ISDN era".
[12] CCITT Recommendation G.101 (1988): "The transmission plan".
[13] TBR 3: "Integrated Services Digital Network (ISDN); Attachment requirements
for terminal equipment to connect to an ISDN using ISDN basic access".
[14] IEC Publication 651: "Sound level meters".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of this I-ETS, the relevant definitions given in CCITT Recommendations P.10 [2] and
G.701 [3] apply along with the following:
designated terminal: Refers to the terminal which is permitted to draw power from Power Source 1
under restricted power conditions as specified in CCITT Recommendation I.430 [4].
digital interface: The B-channels available at the coincident S and T reference point at an ISDN basic
access.
handsfree telephony terminal: A telephony terminal using a loudspeaker associated with an amplifier as
a telephone receiver and which can be used without a handset [based on CCITT Recommendation P.10
[2]].
loudspeaking telephony terminal: A handset telephony terminal using a loudspeaker associated with an
amplifier as a telephone receiver [based on CCITT Recommendation P.10 [2]].
multimedia terminal: A terminal which simultaneously supports two or more media (e.g. audio, video,
text, data).
multiservice terminal: A terminal which supports more than one service (bearer service or teleservice).
restricted power condition: Is described in CCITT Recommendation I.430 [4]. The condition is indicated
by the reversed polarity of the phantom voltage at the coincident S and T reference point.
NOTE: For some networks restricted power condition is the normal operating mode.
telephony terminal: A terminal which supports telephony 3,1 kHz teleservice and/or telephony 7 kHz
teleservice.
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I-ETS 300 245-1: February 1996
telephony 3,1 kHz teleservice: A teleservice providing speech transmission at an audio bandwidth of
3,1 kHz. The communication is bi-directional, with both directions active during the speech phase. User
information is provided over a B-channel, signalling is provided over the D-channel [based on
ETS 300 111, clause 5].
telephony 7 kHz teleservice: A real-time teleservice in which speech (7 kHz or 3,1 kHz bandwidth) can
be interchanged using one circuit-mode 64 kbit/s connection [based on ETS 300 267-1 [7]]
3,1 kHz terminal: A terminal which supports telephony 3,1 kHz teleservice.
7 kHz terminal: A terminal which supports telephony 7 kHz teleservice.
3.2 Abbreviations
For the purposes of this I-ETS, the following abbreviations, plus the relevant abbreviations in CCITT
Recommendations P.10 [2] and G.701 [3], apply:
BC Bearer Capability
DTMF Dual Tone Multi Frequency (the same as MFPB - Multi Frequency Push Button)
HLC High Layer Compatibility
ISDN Integrated Services Digital Network
LLC Low Layer Compatibility
MSN Multiple Subscriber Number
SUB Subaddressing
UDI Unrestricted Digital Information
UDI-TA Unrestricted Digital Information with Tones and Announcements (previously
called 7 kHz audio in ETS 300 102-1 [5])
4 Access channel selection
Access through any B-channel shall be possible. Channel allocation shall be in accordance with
ETS 300 102-1 [5].
The functional characteristics of the terminal shall be independent of the B-channel selected.
Compliance shall be tested in accordance with ETS 300 104 [6] by random choice of the B-channel.
5 Call control functions
Call control functions for telephony services (telephony 3,1 kHz teleservice and telephony 7 kHz
teleservice) specified here are based upon ETS 300 102-1 [5] and, where applicable, on ETS 300 267-1
[7] Call control functions for other telephony functions or services are specified below or in other parts of
this I-ETS.
5.1 Outgoing calls
The complete procedures for both en-bloc and overlap sending according to ETS 300 102-1 [5] shall be
implemented.
5.1.1 Coding of Bearer capability information element
Compliance to the requirements specified in subclause 5.1.1 shall be checked using the tests specified in
I-ETS 300 322 [8].
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I-ETS 300 245-1: February 1996
5.1.1.1 Telephony 3,1 kHz teleservice
When initiating an outgoing call on the telephony 3,1 kHz teleservice, the information transfer capability
field of the Bearer capability information element in the outgoing SETUP message shall be set to "speech"
and the user information layer 1 protocol field shall be set to "G.711, A-law" as specified in ETS 300 102-1
[5], subclause 4.5.5.
5.1.1.2 Telephony 7 kHz teleservice
When initiating an outgoing call on the telephony 7 kHz teleservice a fall-back procedure to the telephony
3,1 kHz teleservice shall be available (fall-back allowed).
NOTE: When this option is used, the network will reserve any required echo cancellation
devices, A-law to μ-law converters, etc., in case a "speech" information transfer
capability is used for the resultant connection.
It shall be possible to disable the fall-back procedure (fall-back not allowed).
The signalling procedures for fall-back allowed and fall-back not allowed are specified in ETS 300 267-1
[7], subclause 6.5.1.
5.1.1.3 Interim solution before the introduction of telephony 7 kHz teleservice (optional)
For an interim period of time, some networks need not support the information transfer capability value
"UDI-TA" in the Bearer capability information element and the fall-back procedure (the use of two BC
information elements in the SETUP message).
In the first case, if a single Bearer capability element, coded as specified in subclause 5.1.1.2 is sent, the
call will be rejected by the network.
In the second case, if two Bearer capability elements, coded as specified in subclause 5.1.1.2 are sent,
only the first Bearer capability element (containing the "Speech" information transfer capability value) will
be transmitted by the network to the called terminal.
As an interim procedure, where a terminal is attached to a network that does not support the normal
operation as defined in the previous subclause, the user may obtain a service similar to the telephony
7 kHz teleservice, possibly without tones and announcements, by requesting the circuit mode 64 kbit/s
unrestricted 8 kHz structured bearer service category ("UDI"). Details for the encoding are described in
ETS 300 102-1 [5]. The user information layer 1 protocol field shall be encoded "Recommendation H.221
and H.242". When this information element is used, no High layer compatibility information element shall
be included in the SETUP message.
NOTE: When the circuit mode 64 kbit/s unrestricted 8 kHz structured bearer service category
is used, the network will provide no tones or announcements in the B-channel.
Information on a harmonized set of information tones locally generated on the basis of
information received in the D-channel can be found in Part 7 of this I-ETS.
5.1.1.4 Other services
In the case of other speech coding algorithms, a 64 kbit/s transparent channel may be required. In those
cases "UDI-TA" or "UDI" can be used for the information transfer capability field of the Bearer capability
information element. Details for the use of these Bearer capability elements are given in other parts of this
I-ETS and in other relevant standards (e.g. ETSI ETS 300 102-1 [5], subclause 4.5.5).
NOTE: If octet 3 of the Bearer capability information element indicates "speech", "3,1 kHz
audio" or "UDI-TA", networks conforming to ETS 300 102-1 [5] and ETS 300 267-1 [7]
will provide information tones encoded to A-law in accordance with CCITT
Recommendation G.711 [9] and transmitted on the B-channel (see also
subclause 5.3).
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I-ETS 300 245-1: February 1996
5.1.2 Coding of High layer compatibility information element
In order to avoid possible compatibility problems between a basic 3,1 kHz terminal (supporting only
telephony 3,1 kHz teleservice) and a multimedia or multiservice terminal, the High layer compatibility
information element shall be included in the SETUP message from any telephony terminal complying with
this I-ETS when using telephony 3,1 kHz or 7 kHz teleservice.
The encoding of the High layer compatibility information element for telephony 3,1 kHz teleservice and for
telephony 7 kHz teleservice shall be as specified in ETS 300 102-1 [5], subclause 4.5.16 with the high
layer characteristic identification field set to "telephony".
For the interim solution described in subclause 5.1.1.3, the HLC information element shall not be included
in the SETUP message.
Compliance shall be checked using the tests specified in I-ETS 300 322 [8].
5.1.3 Coding of Low layer compatibility information element
In order to avoid possible compatibility problems between a basic 3,1 kHz terminal and a multimedia or
multiservice terminal, the Low layer compatibility information element may, in most cases, be included in
the SETUP message from telephony terminals.
In the case where two Bearer capability information elements are included in the SETUP message the
Low layer compatibility information element shall not be included in the SETUP message.
If the Low layer compatibility information element is included in the SETUP message the encoding of the
element for telephony 3,1 kHz teleservice shall be as specified in ETS 300 102-1 [5], subclause 4.5.18
with the information transfer capability field set to "speech" and, if optionally provided, the user information
layer 1 protocol field set to "G.711, A-law".
Compliance shall be checked using the tests specified in I-ETS 300 322 [8].
5.1.4 Coding of Called party number information element
When initiating an outgoing call on a telephony teleservice (3,1 kHz or 7 kHz), the default coding of the
"Type of number" and "Numbering plan identification" fields in the information element shall both be
"unknown" as specified in ETS 300 102-1 [5], subclause 4.5.8.
In cases where the human user can control the content of this element, other codings may be appropriate.
See ETS 300 102-1 [5], subclause 4.5.8.
Compliance shall be checked using the tests specified in I-ETS 300 322 [8].
NOTE: In the dialling procedure the separation between the Called Party Number and the
Called Party Subaddress is for further study.
5.1.5 Indication of resultant service
If the originating terminal specifies a preferred service (e.g. telephony 7 kHz teleservice) with fall-back
allowed, the resultant service will be indicated to the originating terminal by the procedures specified in
ETS 300 267-1 [7], clauses 5 and 6. If fall-back occurs the requirements for the preferred service no
longer apply.
The in-band requirements for the different telephony services are given in the appropriate parts of this
I-ETS.
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I-ETS 300 245-1: February 1996
5.2 Incoming calls
5.2.1 Compatibility checking
For a multiservice terminal which supports telephony 3,1 or 7 kHz teleservice, the terminal shall, in
association with its function of supporting these services, meet the requirements specified in
subclause 5.2 of this I-ETS for handling incoming telephony calls. However, in association with the
support of other bearer services or teleservices, it may accept as compatible incoming calls with Bearer
capability (BC), High layer compatibility (HLC), and Low layer compatibility (LLC) information elements
other than those specified in that subclause.
NOTE: In the future there may exist telephony terminals which requires Bearer capabilities
other than "speech", "3,1 kHz audio" or "7 kHz audio" as well as High layer
compatibility information element analysis (e.g. low bit-rate telephony and multiservice
terminals). Interworking between such terminals and 3,1 kHz telephony terminals is
envisaged. The inclusion of compatibility checking procedures which take into account
this interworking is for further study.
5.2.1.1 Analysis of Bearer capability information element
A terminal which is using CCITT Rec
...