SIST I-ETS 300 302-4 E1:2003

• Abstract:

  Standardization of electroacoustical characteristics of videotelephony terminals for Integrated Services Digital Network using wideband (CCITT G.722) coding and handset functions.

• 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 300 302-4 ed.1 (1996-09) - Integrated Services Digital Network (ISDN); Videotelephony teleservice; Part 4: Audio aspects - wideband coding and loudspeaking or handsfree function

SIST I-ETS 300 302-4 E1:2003 is the Slovenian adoption of ETSI’s Interim European Telecommunication Standard for Integrated Services Digital Network (ISDN) videotelephony, Part 4. It specifies electroacoustic characteristics for videotelephony terminals that use 7 kHz wideband coding and loudspeaking or handsfree functions on ISDN basic access. It is written for terminal designers, test laboratories, and manufacturers who need to design, measure, or declare audio performance for these terminals.

What does SIST I-ETS 300 302-4 E1:2003 specify?

SIST I-ETS 300 302-4 E1:2003 specifies the audio-related characteristics of ISDN videotelephony terminals and focuses on the points that differ from ordinary ISDN 7 kHz telephony terminals. The main practical differences are the videotelephony operating conditions, such as delay and measurement position.

The document is organized into a foreword, Scope, Normative references, Definitions and abbreviations, Requirements, and one informative annex. Annex A is a bibliography.

The scope places the standard on videotelephony terminals that use Adaptive Differential Pulse Code Modulation (ADPCM) according to CCITT Recommendation G.722 and are connected to the basic access of the coincident S and T reference point. It also points readers to the related ISDN videotelephony service description and to the corresponding telephony terminal requirements where the same characteristics are covered outside videotelephony.

What are the key requirements of SIST I-ETS 300 302-4 E1:2003?

The standard builds on the loudspeaking and handsfree telephony requirements of I-ETS 300 245-6 and I-ETS 300 245-5, then adds videotelephony-specific conditions. In practice, most of the document tells you which base requirements still apply and where the test setup or target values are adjusted for video use.

• Clause 4.1.1 sets the normal operating mode to b2 mode as defined in ETS 300 145, with speech in one B-channel and video in the same connection. G.722 coding at 64 kbit/s is not mandatory, and testing follows the implemented 48 kbit/s or 56 kbit/s case, so designers must check the lower-rate, worst-case audio behavior.
• Clause 4.1.2 introduces a standard user position for compact terminals and requires measurements to use a correction factor F based on the distance to the user. For terminals with a separated acoustic front end, the supplier declares the test position, which matters because geometry changes the measured loudness.
• Clause 4.3 sets nominal Sending Loudness Rating (SLR) and Receiving Loudness Rating (RLR) values and a minimum RLR at maximum manual volume control, with a ±3 dB manufacturing tolerance. This is the core set-up target for send and receive loudness.
• Clause 4.4 requires at least 15 dB of user-controllable output range and limits how RLR changes between -15 dBm0 and -30 dBm0. If automatic gain control is used, its behavior must not create an excessive increase in receive loudness.
• Clauses 4.2, 4.5, 4.7 and 4.11 reuse the sensitivity, Terminal Coupling Loss (TCL), stability, out of band signal, and switching requirements and test methods from I-ETS 300 245-6 and I-ETS 300 245-3. That means many compliance checks follow the established 7 kHz telephony test regime.
• Clause 4.6 sets sending and receiving distortion limits using frequency- and level-dependent tables for 300 Hz, 1 kHz, and 6 kHz. Test labs need these tables because the allowed Signal to Distortion (S/D) ratio changes with tone level.
• Clause 4.8 limits idle-mode noise in both directions, including a sending-path A-weighted noise limit and a receiving-path limit that depends on F. Clause 4.9 refers delay requirements to part 3, and clause 4.10 gives no normative lip-synchronisation requirement but notes that a 25 ms delay difference is a good target.

What terms does SIST I-ETS 300 302-4 E1:2003 define?

SIST I-ETS 300 302-4 E1:2003 defines the acoustic and measurement terms used to assess videotelephony terminals.

• Acoustic Reference Level (ARL) is the acoustic level that corresponds to -10 dBm0 at the digital interface.
• Hands-Free Reference Point (HFRP) is the calibration point on the axis of the artificial mouth, 50 cm from the lip ring, used for free-field measurement.
• hands-free function means the user does not hold a handset or other transducer at the ear, and the microphone(s) and loudspeaker(s) may be arranged freely.
• loudspeaking function means the handset is in its normal position while the incoming signal is also presented through loudspeaker(s).
• Terminal Coupling Loss (TCL) is the frequency-dependent loss between receive and send ports caused by acoustic, electrical, and mechanical coupling.
• Weighted Terminal Coupling Loss (TCLw) is TCL evaluated with the weighting of ITU-T Recommendation G.122.
• Sending Loudness Rating (SLR) and Receiving Loudness Rating (RLR) are the loudness measures used to set and check send and receive levels for the terminal.

Who uses SIST I-ETS 300 302-4 E1:2003?

SIST I-ETS 300 302-4 E1:2003 is used by videotelephony terminal manufacturers, acoustic engineers, test laboratories, and quality teams that verify ISDN audio performance. It is also useful for buyers or specifiers who need to know what audio behavior a terminal should meet before procurement or acceptance testing.

In practice, users apply it when designing microphones, loudspeakers, volume control behavior, and idle-noise performance, and when setting up compliance tests that depend on user position, coupling loss, distortion, and delay.

Which standards are used with SIST I-ETS 300 302-4 E1:2003?

Clause 2 names the main normative references, and the scope and annex point to the related service and coding documents that frame the standard.

• ETS 300 245-6 - provides the base requirements and test methods for wideband 7 kHz loudspeaking and handsfree telephony.
• ETS 300 145 - defines the videotelephone system, its modes of operation, and its terminal types.
• I-ETS 300 245-5 - provides the wideband handset telephony reference.
• I-ETS 300 245-3 - provides the PCM A-law loudspeaking and handsfree telephony reference, including switching characteristics.
• prI-ETS 300 302-3 - provides the delay requirements for the wideband handset part of the same videotelephony series.
• CCITT Recommendation G.711 - gives the PCM voice coding reference used in the document’s reference set.
• ETS 300 264 - describes the ISDN videotelephony teleservice that these terminals support.
• CCITT Recommendation G.722 - gives the 7 kHz audio coding context used for the wideband terminal requirement.
• ITU-T Recommendations H.261, G.122, P.51, and P.64 - support the lip-sync note, coupling-loss weighting, artificial mouth calibration, and sensitivity/frequency measurement background.

What does the SIST I-ETS 300 302-4 E1:2003 document contain?

The document contains the service context, terms, and measurement framework needed to assess audio performance in ISDN videotelephony terminals. It includes the operating mode assumptions, user-position rules, loudness ratings, volume-control behavior, distortion limits, noise limits, delay reference, and switching requirements.

Tables 1 and 2 give the sending and receiving Signal to Distortion limits at selected tone frequencies and levels. Annex A collects the supporting bibliography used for coding, stability, artificial mouth calibration, and related videotelephony references.

SLOVENSKI STANDARD
01-december-2003
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Integrated Services Digital Network (ISDN); Videotelephony teleservice; Part 4: Audio
aspects - wideband coding and loudspeaking or handsfree function
Ta slovenski standard je istoveten z: I-ETS 300 302-4 Edition 1
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 300 302-4
TELECOMMUNICATION September 1996
STANDARD
Source: ETSI TC-TE Reference: DI/TE-04008.4
ICS: 33.080
Key words: ISDN, videotelephony terminals, audio, handsfree, loudspeaking, wideband, 7 kHz
Integrated Services Digital Network (ISDN);
Videotelephony teleservice;
Part 4: Audio aspects - wideband coding and
loudspeaking or handsfree function
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail]
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 300 302-4: September 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 300 302-4: September 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 Requirements.9
4.1 General .9
4.1.1 Encoding .9
4.1.2 Standard user's position.9
4.1.2.1 "Compact" terminal.9
4.1.2.2 Terminal with separated acoustic front end.9
4.1.3 Volume control .10
4.1.4 Test considerations .10
4.2 Sensitivity - frequency response .10
4.3 Sending and Receiving Loudness Ratings .10
4.4 Volume control range.10
4.5 Terminal Coupling Loss .10
4.5.1 Weighted Terminal Coupling Loss .10
4.5.2 Stability.10
4.6 Distortion.10
4.6.1 Sending distortion.10
4.6.2 Receiving distortion .11
4.7 Out of band signals.11
4.8 Noise.11
4.8.1 Sending .11
4.8.2 Receiving.12
4.8.2.1 A-Weighted noise .12
4.9 Delay.12
4.10 Lip synchronisation .12
4.11 Switching characteristics.12
Annex A (informative): Bibliography.13
History.14

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I-ETS 300 302-4: September 1996
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I-ETS 300 302-4: September 1996
Foreword
Part 4 of this Interim European Telecommunication Standard (I-ETS) has been 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 I-ETS is part 4 of a multipart standard covering "Integrated Services Digital Network (ISDN);
Videotelephony teleservice", as described below:
Part 1: "Electroacoustic characteristics for handset telephony function when using Pulse Code
Modulation encoding".
Part 2: "Audio aspects - Pulse Code Modulation (PCM) A-law loudspeaking and handsfree".
Part 3: "Audio aspects - wideband handset".
Part 4: "Audio aspects - wideband coding and loudspeaking or handsfree function".
Proposed announcement date
Date of adoption of this I-ETS: 23 August 1996
Date of latest announcement of this I-ETS (doa): 31 December 1996

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I-ETS 300 302-4: September 1996
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I-ETS 300 302-4: September 1996
1 Scope
This Interim European Telecommunication Standard (I-ETS) specifies the electroacoustic characteristics
for 7 kHz bandwidth loudspeaking and handsfree functions implemented in videotelephony terminals
intended for use in the videotelephone teleservice in the Integrated Services Digital Network (ISDN) using
Adaptive Differential Pulse Code Modulation (ADPCM) encoding according to
CCITT Recommendation G.722 (see annex A). Those terminals will be connected to the basic access of
the coincident S and T reference point of the ISDN.
The videotelephony teleservice in the ISDN is described in ETS 300 264 (see annex A).
The requirements of this I-ETS specify those characteristics which deviate from those of an ISDN 7 kHz
telephony terminal. Those deviations are due to conditions which are special for videotelephony
applications (e.g. delay, measurement position). The corresponding requirements for an ISDN 7 kHz
telephony loudspeaking and handsfree terminal can be found in I-ETS 300 245-6 [1].
2 Normative references
This I-ETS incorporates by dated and 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 referred to applies.
[1] ETS 300 245-6: "Integrated Services Digital Network (ISDN); Technical
characteristics for telephony terminals; Part 6: Wideband (7 kHz) loudspeaking
and handsfree telephony".
[2] ETS 300 145 (Second edition): "Integrated Services Digital Network (ISDN);
Audiovisual services; Videotelephone systems and terminal equipment
operating on one or two 64 kbit/s channels".
[3] I-ETS 300 245-5: "Integrated Services Digital Network (ISDN); Technical
characteristics of telephony terminals; Part 5: Wideband (7 kHz) handset
telephony".
[4] I-ETS 300 245-3: "Integrated Services Digital Network (ISDN); Technical
characteristics of telephony terminals; Part 3: Pulse Code Modulation (PCM)
A-law, loudspeaking and handsfree telephony".
[5] Draft prI-ETS 300 302-3: "Integrated Services Digital Network (ISDN);
Videotelephony teleservice; Part 3: Audio aspects - wideband handset".
[6] CCITT Recommendation G.711 (1990): "Pulse code modulation (PCM) of voice
frequencies".
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I-ETS 300 302-4: September 1996
3 Definitions and abbreviations
3.1 Definitions
For the purposes of this part of the I-ETS, the following def
...