ETSI I-ETS 300 245-3 ed.1 (1995-02)

SLOVENSKI STANDARD
SIST I-ETS 300 245-3 E1:2003
01-december-2003
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Integrated Services Digital Network (ISDN); Technical characteristics of telephony
terminals; Part 3: Pulse Code Modulation (PCM) A-law, loudspeaking and handsfree
telephony
Ta slovenski standard je istoveten z: I-ETS 300 245-3 Edition 1
ICS:
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
SIST I-ETS 300 245-3 E1:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST I-ETS 300 245-3 E1:2003

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SIST I-ETS 300 245-3 E1:2003
INTERIM
EUROPEAN I-ETS 300 245-3
TELECOMMUNICATION February 1995
STANDARD
Source: ETSI TC-TE Reference: T/TE 10-07 (C)
ICS: 33.080
ISDN, telephony terminals
Key words:
Integrated Services Digital Network (ISDN);
Technical characteristics of telephony terminals
Part 3: Pulse Code Modulation (PCM) A-law,
loudspeaking and handsfree telephony
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 - secretariat@etsi.fr
X.400: Internet:
Tel.: +33 92 94 42 00 - Fax: +33 93 65 47 16
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 1995. All rights reserved.
New presentation - see History box

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I-ETS 300 245-3: February 1995
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 300 245-3: February 1995
Contents
Foreword .7
1 Scope .9
2 Normative references.9
3 Definitions and abbreviations .10
3.1 Definitions .10
3.2 Abbreviations .11
4 Call control functions.11
5 Transmission aspects .11
5.1 General .11
5.1.1 Encoding .11
5.1.2 Relative level .11
5.1.3 Volume control .12
5.1.4 Requirements applicable to Hands-Free Telephone, Loudspeaking
Telephony and Call Progress Monitoring .12
5.2 Sensitivity frequency response .13
5.2.1 Sending .13
5.2.2 Receiving.13
5.3 Loudness ratings.15
5.3.1 Sending .15
5.3.2 Receiving.15
5.3.2.1 Maximum sensitivity.15
5.3.2.2 Volume control range .15
5.3.3 Adaptive gain control (optional).15
5.4 Terminal Coupling Loss (TCL).16
5.4.1 Hands-free function.16
5.4.2 Loudspeaking function .16
5.4.3 Call Progress Monitoring (CPM).17
5.5 Stability loss .17
5.5.1 Hands free function .17
5.5.2 Loudspeaking function .17
5.6 Distortion.17
5.6.1 Harmonic distortion (sinusoidal signal).17
5.6.1.1 Sending.17
5.6.1.2 Receiving.18
5.6.2 Total distortion (pseudo-random noise signal) .18
5.6.2.1 Sending.18
5.6.2.2 Receiving.18
5.7 Out-of-band signals .18
5.7.1 Sending .18
5.7.2 Receiving.19
5.8 Noise.19
5.8.1 Sending .19
5.8.1.1 Idle mode.19
5.8.1.2 Noise during transition from active mode to idle mode .19
5.8.2 Receiving.19
5.8.2.1 Idle mode.19
5.8.2.1.1 A-weighted.19
5.8.2.1.2 Third-octave band spectrum.19
5.8.2.2 Noise during transition from active mode to idle mode .20
5.9 Delay.20
5.10 Switching characteristics.20
5.11 Acoustic Echo Controllers characteristics.20

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I-ETS 300 245-3: February 1995
5.12 Articulation. 21
Annex A (normative): Test specification . 22
A.1 Test considerations . 22
A.1.1 Test signals . 22
A.1.1.1 Broadband signal. 22
A.1.1.2 Sinusoidal and narrow-band signals. 23
A.1.2 Test signal levels. 23
A.1.2.1 Sending. 23
A.1.2.2 Receiving . 23
A.1.3 Test rooms . 24
A.1.3.1 Anechoic room. 24
A.1.3.2 "Anechoic" tests in a reverberant field . 25
A.1.4 Test arrangement. 26
A.1.4.1 Hands-free function . 26
A.1.4.2 Loudspeaking function. 26
A.1.5 Alternative test methods. 27
A.2 Transmission requirements testing . 27
A.2.1 Sensitivity/frequency response. 27
A.2.1.1 Sending. 28
A.2.1.2 Receiving . 28
A.2.2 Loudness ratings. 28
A.2.2.1 Sending Loudness Rating (SLR) . 28
A.2.2.2 Receiving Loudness Rating (RLR) . 29
A.2.3 Terminal Coupling Loss . 29
A.2.4 Stability loss. 29
A.2.4.1 Hands-Free function . 29
A.2.4.2 Loudspeaking function. 29
A.2.5 Distortion . 29
A.2.5.1 Harmonic distortion (sinusoidal signal). 29
A.2.5.1.1 Sending. 29
A.2.5.1.2 Receiving . 30
A.2.5.2 Total distortion (pseudo-random noise signal) . 30
A.2.5.2.1 Sending. 30
A.2.5.2.2 Receiving . 30
A.2.6 Out-of-band signals. 30
A.2.6.1 Sending. 30
A.2.6.2 Receiving . 30
A.2.7 Noise . 30
A.2.7.1 Sending. 30
A.2.7.1.1 Idle mode . 31
A.2.7.1.2 Noise during the transition active mode to idle mode . 31
A.2.7.2 Receiving . 31
A.2.7.2.1 Idle mode . 31
A.2.7.2.2 Noise during transition from active mode to idle mode. 31
A.2.8 Delay . 31
A.2.9 Switching characteristics. 32
A.2.9.1 Test signal levels . 32
A.2.9.2 Build-up time. 32
A.2.9.3 Switching time. 32
A.2.10 Echo cancelling characteristics . 33
A.2.11 Articulation. 33
Annex B (informative): Description of the Composite Source Signal (CSS) . 34
B.1 General presentation of the CSS. 34
B.2 Use of the CSS. 40
B.2.1 Calculation and analysis. 40
B.2.1.1 Principle of acoustical and electrical calibration - test signal levels. 40
B.2.1.2 Analysis parameters . 40

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B.2.2 Principles of testing applied to annex A.41
B.2.2.1 Measurements of frequency responses, TCL and Loudness Ratings, in
single talk conditions .41
B.2.2.2 Distortion measurements .41
B.2.2.3 Out-of-band measurements .41
B.2.2.4 Noise measurements .41
B.2.2.5 Delay measurements .42
B.2.2.6 Switching characteristics.42
B.2.2.7 Echo cancelling characteristics .42
B.3 Practical Composite Source Signal.42
B.3.1 Voiced signal to simulate voice properties.42
B.3.2 Pseudo noise signal.43
B.3.3 Pause.43
Annex C (informative): Bibliography.44
History.45

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I-ETS 300 245-3: February 1995
Foreword
Part three 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 its life extended for a further two
years, be replaced by a new version or, be withdrawn.
This is the third Part of an I-ETS which is currently intended to comprise eight Parts:
Part 1: "General (I-ETS 300 245-1 [1])".
Part 2: "PCM A-Law, handset telephony (I-ETS 300 245-2 [2])".
Part 3: "Pulse Code Modulation (PCM) A-Law, Loudspeaking and handsfree telephony".
Part 4: Interface for additional equipment.
Part 5: Wideband (7 kHz) telephony.
Part 6: Wideband (7 kHz) handsfree telephony.
Part 7: Locally generated information tones.
Part 8: Terminal application of 16 kbit/s speech coding algorithms (T/TE 10-07H).
Proposed announcement date
Date of latest announcement of this I-ETS (doa): 31 May 1995

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1 Scope
Part 3 of this I-ETS specifies technical characteristics for Pulse Code Modulation (PCM) A-law, 3,1 kHz
loudspeaking and handsfree telephony terminals to be used at the basic access for the coincident S and T
reference point of the Integrated Services Digital Network (ISDN).
Such terminals are intended to be used by a single person.
This Part of I-ETS 300 245 applies in conjunction with I-ETS 300 245-1 [1] and the characteristics
specified in this Part are additional to those of I-ETS 300 245-1 [1].
2 Normative references
Part 3 of 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 Part 3 of this I-ETS only when incorporated in it by amendment or revision. For undated
references the latest edition of the publication referred to apply.
[1] I-ETS 300 245-1: "Integrated Services Digital Network (ISDN); Technical
characteristics of telephony terminals, Part 1: General".
[2] I-ETS 300 245-2: "Integrated Services Digital Network (ISDN); Technical
characteristics of telephony terminals, Part 2: PCM A-law handset telephony".
[3] ITU-T Recommendation P.10 (1993): "Vocabulary of terms on telephone
transmission quality and telephone sets".
[4] CCITT Recommendation G.701 (1988): "Vocabulary of digital transmission and
multiplexing, and pulse code modulation (PCM) terms".
[5] ETS 300 111 (1992): "Integrated Services Digital Networks (ISDN); Telephony
3,1 kHz teleservice, Service description".
[6] CCITT Recommendation G.122 (1988): "Influence of national systems on
stability, talker echo, and listener echo in international connections".
[7] ITU-T Recommendation P.51 (1993): "Artificial mouth".
[8] CCITT Recommendation G.711 (1988): "Pulse code modulation (PCM) of voice
frequencies".
[9] ITU-T Recommendation P.34 (1993): "Transmission characteristics of hands-
free telephones".
[10] CCITT Recommendation O.131 (1988): "Quantizing distortion measuring
equipment using a pseudo-random noise test signal".
[11] ISO 266 (1975): "Acoustics - Preferred frequencies for measurements".
[12] ITU-T Recommendation P.79 (1993): "Calculation of loudness ratings for
telephone sets".
[13] CCITT Recommendation G.223 (1988 ): "Assumptions for the calculation of
noise on hypothetical reference circuits for telephony".
[14] CCITT Recommendation O.41 (1988): "Psophometer for use on telephone-type
circuits".
[15] IEC 651 (1979): "Sound level meters".

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I-ETS 300 245-3: February 1995
3 Definitions and abbreviations
3.1 Definitions
For the purposes of this Part of the I-ETS, the relevant definitions given in ITU-T Recommendations P.10
[3] and G.701 [4] apply along with the following:
Acoustic Reference Level (ARL): The acoustic level which gives - 10 dBm0 at the digital interface.
telephony 3,1 kHz teleservice: A description of telephony 3,1 kHz teleservice is given in ETS 300 111
[5], clause 5.
loudspeaking function: The handset is used in the normal position. The incoming signal is
simultaneously presented to the user(s) from loudspeaker(s).
hands-free function: For free handling no handset or any other equipment with transducers is held to the
ear of the user. If a handset is implemented then it is placed at a distance from the user. Normally, the
handset is not active. The numbers, the implementation and the use of microphone(s) and loudspeaker(s)
are not limited.
Call Progress Monitoring (CPM): The loudspeaker is used to monitor the received signals while the
voice transmission in the sending direction is disconnected.
Terminal Coupling Loss (TCL): The frequency dependent coupling loss between the receiving port and
sending port of a terminal due to:
- acoustical coupling at the user interface;
- electrical coupling due to crosstalk in the handset cord or within the electrical circuits;
- seismic coupling through the mechanical parts of the terminal.
NOTE 1: The receiving port and the sending port of a digital voice terminal is a 0 dBr point.
NOTE 2: The coupling at the user interface depends on the conditions of use.
weighted Terminal Coupling Loss (TCLw): The Terminal Coupling Loss (TCL) calculated using the
weighting of CCITT Recommendation G.122 [6].
Hands-Free Reference Point (HFRP): A point located on the axis of the artificial mouth, at 50 cm from
the lip ring, where the level calibration is made, in free field. It corresponds to the measurement point n°
11, as defined in ITU-T Recommendation P.51 [7].
idle mode: Idle mode is when the terminal is not activated by an input signal (e.g. input signal level below
implemented threshold level).
active mode: Active mode is when the terminal is activated by an input signal (e.g. input signal level
above implemented threshold level).
single talk: An operation mode where only one user is speaking.
double talk: An operation mode where two users are speaking simultaneously.

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3.2 Abbreviations
For the purposes of this Part of the I-ETS, the following abbreviations apply:
AEC Acoustic Echo Controller
AGC Automatic Gain Control
Ardt Received speech attenuation during double talk
ARL Acoustic Reference Level
Asdt Sent speech attenuation during double talk
CPM Call Progress Monitoring
CSS Composite Source Signal
ETS European Telecommunication Standard
ETSI European Telecommunications Standards Institute
I-ETS Interim European Telecommunication Standard
ISDN Integrated Services Digital Network
FFT Fast Fourier Transformation
HATS Head And Torso Simulator
HFRP Hands-Free Reference Point
HFT Hands-Free Telephony Terminal
LRGP Loudness Rating Guard-ring Position
LST Loudspeaking Telephony Terminal
MRP Mouth Reference Point
PCM Pulse Code Modulation
PN Pseudo Noise
RLR Receiving Loudness Rating
SLR Sending Loudness Rating
TCL Terminal Coupling Loss
TCLw Weighted Terminal Coupling Loss
TCLwdt Weighted Terminal Coupling Loss - double talk
TCLwst Weighted Terminal Coupling Loss - single talk
Tondt Break in time - double talk
Tonst Break in time - single talk
TR Built up time
TS Switching time
4 Call control functions
The requirements of I-ETS 300 245-1 [1] shall be met.
5 Transmission aspects
5.1 General
Requirements for PCM A-law terminals are given in this Part of the I-ETS.
When using other coding algorithms other Parts of this I-ETS may apply.
5.1.1 Encoding
The default speech encoding algorithm for all speech terminals shall be the A-law encoding at 64 kbit/s,
as defined in CCITT Recommendation G.711 [8].
Any other possible encoding algorithm are additional. For some encoding algorithms, requirements are
given in other Parts of this I-ETS.
5.1.2 Relative level
The digital interface is a 0 dBr point according to CCITT Recommendation G.101.

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5.1.3 Volume control
Unless stated otherwise, the requirements apply for all positions of the user-controlled receiving volume
control, if the volume control is manually operated.
5.1.4 Requirements applicable to Hands-Free Telephone, Loudspeaking Telephony and Call
Progress Monitoring
Table 1 presents the requirements that shall be applicable to Hands-Free Telephony, Loudspeaking
Telephony and Call Progress Monitoring.
The applicability is indicated by an "X" in the corresponding column. The characteristics indicated by "(X)"
are for further study.
For Loudspeaking Telephony Terminals (LSTs), the requirements for handset telephony can be found in I-
ETS 300 245-2 [2].
Table 1: Applicability of requirements
HFT LST CPM
Sensitivity frequency response (5.2)
Sending (5.2.1) X
Receiving (5.2.2) X X
Loudness ratings (5.3)
Sending (5.3.1) X
Receiving (5.3.2.1) Maximum sensitivity X X
Receiving (5.3.2.2) Volume control range X X
Receiving (5.3.3) Adaptive gain control (optional) X
Terminal coupling loss (5.4)
Handsfree Function (5.4.1) X
Loudspeaking Function (5.4.2) X
Call Progress Monitoring (5.4.3) X
Stability loss(5.5.1) Handsfree function X
Stability loss(5.5.2) Loudspeaking function X
Distortion (5.6)
Harmonic distortion (5.6.1.1) Sending X
Harmonic distortion (5.6.1.2) Receiving X X
Total distortion (5.6.2.1) Sending X
Total distortion (5.6.2.2) Receiving X X
Out-of-band signals (5.7)
Sending (5.7.1) X
Receiving (5.7.2) X X
Noise (5.8)
Sending (5.8.1) X
Receiving (5.8.2) X X
Delay (5.9) X
Switching characteristics (5.10)
Build-up time X
Switching time X X
Acoustic Echo Controllers characteristics (5.11) (X) (X)
(X) (X)
Articulation (5.12)

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5.2 Sensitivity frequency response
5.2.1 Sending
The sending sensitivity frequency response, from Mouth Reference Point (MRP) to digital interface, shall
be within the mask drawn in figure 1.
6
4
Sensitivity
2
(dB)
Relative level
0
12dB
-2
-4
-6
-8
-10
-12
-14
100 160 250 400 630 1k 1,6k 2,5k 4k 6,3k 10k
Frequency
125 800 1,25k 2k 3,1k 5k 8k
200 315 500
(Hz)
Sending frequency target
Figure 1: Sending sensitivity frequency mask for HFT
All sensitivity values are dB on an arbitrary scale.
Compliance shall be checked by the test described in annex A, subclause A.2.1.1.
NOTE: A sending sensitivity frequency response target is included in figure 1.
5.2.2 Receiving
The receiving sensitivity frequency responses, from the digital interface to the measuring point C, shall be
within the masks drawn on figures 2 and 3 respectively for Hands-Free Telephony Terminals (HFTs) and
Loudspeaking Telephony Terminals (LSTs).
All sensitivities are dB on an arbitrary scale.
Compliance shall be checked by the test described in annex A, subclause A.2.1.2.
NOTE: A receiving sensitivity frequency response target is included in figure 2.

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Sensitivity
(dB)
Relative level
2
0
-
2
-4
12dB
-6
-8
-10
-12
-
14
-
16
-18
100 160 250 400 630 1k 1,6k 2,5k 4k 6,3k 10k
Frequency
125 200 315 500 800 1,25k 2k 3,1k 5k 8k
(Hz)
Receiving frequency target
Figure 2: Receiving sensitivity frequency mask for HFT
Sensitivity
(dB)
Relative level
2
0
-2
-4
-6
15dB
-8
-10
-12
-
14
-16
-18
100 160 250 400 630 1k 1,6k 2,5k 4k 6,3k 10k
125 800 1,25k 2
...