SIST I-ETS 300 245-3 E1:2003

Integrated Services Digital Network (ISDN); Technical characteristics of telephony terminals; Part 3: Pulse Code Modulation (PCM) A-law, loudspeaking and handsfree telephony

To specify the speech transmission characteristics of a loudspeaking or handsfree terminal to be used at the S/T interface of ISDN basic access

Digitalno omrežje z integriranimi storitvami (ISDN) – Tehnične karakteristike telefonskih terminalov – 3. del: Telefonija z zvočniškimi in prostoročnimi terminali z uporabo impulzno-kodne modulacije (PCM) s pretvorbo govora po pravilu A-law

General Information

• 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 300 245-3 ed.1 (1995-02) - Integrated Services Digital Network (ISDN); Technical characteristics of telephony terminals; Part 3: Pulse Code Modulation (PCM) A-law, loudspeaking and handsfree telephony

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2003
'LJLWDOQRRPUHåMH]LQWHJULUDQLPLVWRULWYDPL,6'1±7HKQLþQHNDUDNWHULVWLNH
WHOHIRQVNLKWHUPLQDORY±GHO7HOHIRQLMD]]YRþQLãNLPLLQSURVWRURþQLPLWHUPLQDOL
]XSRUDERLPSXO]QRNRGQHPRGXODFLMH3&0VSUHWYRUERJRYRUDSRSUDYLOX$ODZ
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)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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 - [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 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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I-ETS 300 245-3: February 1995
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
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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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I-ETS 300 245-3: February 1995
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I-ETS 300 245-3: February 1995
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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I-ETS 300 245-3: February 1995
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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I-ETS 300 245-3: February 1995
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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I-ETS 300 245-3: February 1995
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.
Sensitivity
(dB)
Relative level
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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I-ETS 300 245-3: February 1995
Sensitivity
(dB)
Relative level
-
-4
12dB
-6
-8
-10
-12
-
-
-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
-4
-6
15dB
-8
-10
-12
-
-16
-18
100 160 250 400 630 1k 1,6k 2,5k 4k 6,3k 10k
125 800 1,25k 2k 3,1k 5k 8k
200 315 500
Figure 3: Receiving sensitivity frequency mask for LST

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I-ETS 300 245-3: February 1995
5.3 Loudness ratings
The values given in this subclause correspond to those for handset telephones as specified in I-ETS 300
245-2 [2] and will need to be adjusted if the referred values are adjusted.
5.3.1 Sending
Nominal value Sending Loudness Rating (SLR) = 12 dB.
There is a manufacturing tolerance of ± 4 dB.
Compliance shall be checked by the test described in annex A, subclause A.2.2.1.
5.3.2 Receiving
5.3.2.1 Maximum sensitivity
If a manually operated volume control is provided, the Receiving Loudness Rating (RLR) value, measured
for the volume control set at its maximum, shall be:
RLR = - 6 dB ± 4 dB (including manufacturing tolerances).
Compliance shall be checked by the test described in annex A, subclause A.2.2.2.
5.3.2.2 Volume control range
With a line level of -15 dBm0 it shall be possible to obtain an RLR value which is at least 15 dB greater
(quieter) than the RLR at - 30 dBm0 with manual and automatic gain control (if provided).
The acoustic output level shall be user controllable with a minimum range of 15 dB.
When a manual gain control is not used and if an automatic gain control is provided, the RLR value
obtained with a line level of - 15 dBm0 shall not exceed that RLR value which is obtained with a line level
of - 30 dBm0 by more than 15 dB. This avoids parts of negative law at the input/output characteristic.
The range of the acoustic output level shall be measured as a change in RLR.
NOTE: The volume control, if it operates manually, controls only the receiving path.
5.3.3 Adaptive gain control (optional)
An adaptive gain control, depending on the level of environmental noise, may be implemented into the set.
The gain variation in the set corresponds to a gain in the receiving path and to a symmetrical attenuation
in the sending path for increased ambient noise level.
Table 2 presents, for guidance and illustration only, three examples of gain variation characteristics.
Table 2: Gain variation characteristics
Ambient noise level Relative gain variation
Single threshold between - 44 dBPa(A) and -39 dBPa(A) 8 dB
Double - 44 dBPa(A) 5 dB
threshold - 34 dBPa(A) 10 dB
Continuous from - 64 dBPa(A) to - 44 dBPa(A) 3 dB
variation from - 44 dBPa(A) to - 24 dBPa(A) 8 dB

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I-ETS 300 245-3: February 1995
5.4 Terminal Coupling Loss (TCL)
5.4.1 Hands-free function
The required values for TCL and TCLw correspond to single talk and one way transmission time, greater
than 25 ms, as defined in table 3.
If information on one way transmission time is available in the terminal from the network, then all values in
table 3 are applicable.
The TCL and TCLw shall be tested with the volume control in its maximum setting. The results shall be
corrected to RLR + SLR = 15 dB.
NOTE: The correction is given by the nominal values of RLR = 3 dB and SLR = 12 dB. These
values are derived from ITU-T Recommendation P.34 [9] for low room noise. Further
study is needed for noisy situations.
Table 3: TCL values HFT
One-way
TCL (1/3 octave band) TCLw
transmission
time
Single talk > 25 ms > 30 dB > 40 dB
> (18) dB > (24) dB
≤ 25 ms
Double talk > 25 ms > (25) dB > (34) dB
> (12) dB > (18) dB
≤ 25 ms
NOTE: Values in brackets are under study.
Compliance shall be checked by the test described in annex A, subclause A.2.3.
5.4.2 Loudspeaking function
The required values for TCL and TCLw corresponding to one way transmission time, greater than 25 ms,
shall result in a TCL greater than 30 dB and a TCLw greater than 40 dB.
When one way transmission time is less than (25) ms, the TCL shall be greater than (18) dB and the
TCLw shall be greater than (24) dB.
NOTE 1: The values in brackets are under study.
The TCL and TCLw shall be tested with the volume control at its maximum setting. The results shall be
corrected to RLR + SLR = 10 dB, according to the handset mode (I-ETS 300 245-2 [2]).
LST Handset
NOTE 2: The correction is given by the nominal values of RLR = 3 dB for loudspeaking and SLR
= 7 dB relevant to low ambient noise. Further study is needed for noisy situations.
If there is a voice switching device for the enhancement of the TCLw, it shall be assumed that, in double
talk, the sending path of the associated handset takes priority over the loudspeaking path.
Compliance shall be checked by the test described in annex A, subclause A.2.3

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I-ETS 300 245-3: February 1995
5.4.3 Call Progress Monitoring (CPM)
The voice transmission in the sending direction shall be disconnected from the B-channel during the use
of the CPM function. TCLw shall be greater than 40 dB.
Compliance shall be checked by test described in annex A, subclause A.2.3.
5.5 Stability loss
The attenuation from the digital input to the digital output shall be, at any time, at least 6 dB for all
frequencies in the range of 200 Hz to 4 kHz.
The test arrangements are defined in annex A, subclause A.1.4.2.
5.5.1 Hands free function
Whatever the signal processing implemented in the HFT, the instantaneous TCL, during any period of the
process, shall be at least 6 dB.
For HFT designed in two or more pieces, the stability shall be evaluated in all the possible arrangements
defined in annex A, subclause A.1.4.1.
Compliance shall be checked by the test described in annex A, subclause A.2.4.1.
5.5.2 Loudspeaking function
The stability of the loudspeaking telephony function shall be tested for an RLR value (measured in
loudspeaking telephony mode) which is 10 dB higher (quieter) than at the maximum of the volume control.
Compliance shall be checked by the test described in annex A, subclause A.2.4.2.
5.6 Distortion
5.6.1 Harmonic distortion (sinusoidal signal)
5.6.1.1 Sending
The ratio of signal to harmonic distortion shall be above the following mask:
Table 4: Signal to harmonic distortion ratio, sending
Frequency Ratio
315 Hz 26 dB
400 Hz 30,5 dB
1 kHz 30,5 dB
Limits at intermediate frequencies lie on a straight line drawn between the given values on a linear (dB
ratio) - logarithmic (frequency) scale.
Compliance shall be checked by the test described in annex A, subclause A.2.5.1.1.

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I-ETS 300 245-3: February 1995
5.6.1.2 Receiving
The ratio of signal to harmonic distortion shall be above the following mask:
Table 5: Signal to harmonic distortion ratio, receiving
Frequency Hands-Free Function Loudspeaking function
315 Hz 26 dB 20 dB
400 Hz 26 dB 26 dB
500 Hz 30,5 dB 30,5 dB
1 kHz 30,5 dB 30,5 dB
Limits at intermediate frequencies lie on a straight line drawn between the given values on a linear (dB
ratio) - logarithmic (frequency) scale.
Limits above 1 kHz are for further study.
Compliance shall be checked by the test described in annex A, subclause A.2.5.1.2.
5.6.2 Total distortion (pseudo-random noise signal)
The values are for further study.
5.6.2.1 Sending
Compliance shall be checked by the test described in annex A, subclause A.2.5.2.1.
5.6.2.2 Receiving
Compliance shall be checked by the test described in annex A, subclause A.2.5.2.2.
5.7 Out-of-band signals
5.7.1 Sending
With any signal defined in annex A, subclause A.2.6, above 4,6 kHz and up to 8 kHz, applied at the
Hands-Free Reference Point (HFRP) at a level of - 28,7 dBPa, the level of any image frequency produced
at the digital interface shall be below a level obtained for the broadband signal (annex A, subclause
A.1.1.1), defined as the reference signal, by at least the amount (in dB) specified in table 6.
Table 6: Out-of-band requirement, sending
Frequency Limit ( minimum )
4,6 kHz 30 dB
8 kHz 40 dB
The limit at intermediate frequencies lies on a straight line drawn between the given values on a linear
(dB)-logarithmic (frequency) scale.
Compliance shall be checked by the test described in annex A, subclause A.2.6.1.

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5.7.2 Receiving
Any spurious out-of-band image signals in the frequency range 4,6 kHz to 8 kHz measured selectively at
the point C shall be lower than the in-band level measured with a broadband reference signal, applied at a
level of - 30 dBm0 . The minimum level of difference between the reference signal level and the out-of-
band image signal level shall be as given in table 7.
Table 7: Out-of-band signals, receiving
Frequency Limit (minimum)
4,6 kHz 35 dB
8 kHz 45 dB
The limit at intermediate frequencies lies on a straight line drawn between the given values on a linear
(dB) - logarithmic (frequency) scale.
Compliance shall be checked by the test described in annex A, subclause A.2.6.2.
5.8 Noise
Three types of noise generated by the HFT or the LST have been identified:
- noise generated by the set in the "idle mode" (see subclauses 5.8.1.1 and 5.8.2.1);
- noise generated by the set when an activation signal is applied. As the noise is masked by the
quantizing and harmonic distortion, the limits are described in subclause 5.6;
- noise generated by the set as soon as the activation signal is interrupted (see subclauses 5.8.1.2
and 5.8.2.2).
5.8.1 Sending
5.8.1.1 Idle mode
The noise produced by the set in the sending path shall not exceed - 64 dBm0p.
Compliance shall be checked by the test described in annex A, subclause A.2.7.1.1.
5.8.1.2 Noise during transition from active mode to idle mode
The mask for this noise requirement versus time is for further study.
Compliance shall be checked by the test described in annex A, subclause A.2.7.1.2.
5.8.2 Receiving
5.8.2.1 Idle mode
5.8.2.1.1 A-weighted
With the volume control set to the maximum, the noise level shall not exceed - 49 dBPa (A).
Compliance shall be checked by the test described in annex A, subclause A.2.7.2.1.
5.8.2.1.2 Third-octave band spectrum
With the volume control set to the maximum, the level in any 1/3 octave band, between 100 Hz and 10
kHz, shall not exceed a value of - 59 dBPa.
Compliance shall be checked by the test described in annex A, subclause A.2.7.2.1.

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5.8.2.2 Noise during transition from active mode to idle mode
The mask for these noise requirements versus time is for further study.
Compliance shall be checked by the test described in annex A, subclause A.2.7.2.2.
5.9 Delay
The delay shall be less than 8 ms (5 ms for the telephone set to allow digital signal processing and 3 ms
for the air path).
Measurements shall be performed on the two paths separately. The delay is the summation of these two
values.
Compliance shall be checked by the test described in annex A, subclause A.2.8.
NOTE: When an Acoustic Echo Controller (AEC) is included in the set, the limit for delay is the
sum of the 8 ms and of the AEC delay defined in subclause 5.11.
5.10 Switching characteristics
The definitions and figures can be found in ITU-T Recommendation P.34 [9], clause 5.
For pure voice switching device, the build-up time (T ) shall be less than 15 ms. For other voice
R
processing technologies implemented in the sets, T is for further study.
R
The switching time (T ) shall be less than 150 ms.
S
Compliance shall be checked by the test described in annex A, subclause A.2.9.
NOTE: Switching characteristics on ambient noise are for further study.
5.11 Acoustic Echo Controllers characteristics
For further study.
NOTE: For the purposes of the HFT specifications, it seems necessary to take into account
some parameters as defined in ITU-T Recommendation G.167. They are listed below:
- TCLwst - single talk. The weighted loss between the Rin and Sout network interfaces
when the AEC is in normal operation, and when there is no signal coming from the
local user;
- TCLwdt - double talk. The weighted loss between the Rin and Sout network interfaces
when the AEC is in normal operation, and where the local user and the far-end user
are active simultaneously;
- Received speech attenuation during double talk (Ardt). The received signal attenuation
(at the Rout point) which is inserted by the AEC during double-talk events. The
frequency response on the receive side during double talk is left for further study;
- Sent speech attenuation during double talk (Asdt). The sent signal attenuation (at the
Sout point) which is inserted by the AEC during double-talk events. The frequency
response on the sent side during double talk is for further study;
- Break-in time - single talk (Tonst). The time interval between the onset of the received
signal (similarly the transmitted signal) and the instant when the attenuation on the
receive path (similarly on the send path) reaches (3) dB. For this purpose, the other
side is quiet;
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- Break-in time - double talk (Tondt). The time interval between the onset of the received
signal (similarly sent signal) and the instant when the attenuation on the receive path
(similarly on the send path) reaches the value Ardt (similarly Asdt). For this purpose,
the signal in the opposite direction of transmission is held at a specified level;
- Delay. The values correspond to the extra delay which can result from the AEC
processing in the processing unit. The maximum delay permitted depends on the
application (see subclause 4.6 of ITU-T Recommendation G.167).
5.12 Articulation
For further study.
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Annex A (normative): Test specification
A.1 Test considerations
A.1.1 Test signals
The test signal levels specified in this annex refer to the active part of the signal.
In order to ensure that the test is representative of the normal operation, the test signal has two functions:
- terminal activation;
- providing the measurement stimulus without adversely affecting the activation.
It shall be checked that both functions are correctly achieved.
Appropriate types of test signal are:
- switched ON/OFF signals, as defined in annex A, subclauses A.1.1.1 and A.1.1.2, at a rate of 250
ms (± 5 ms) ON and 150 ms (± 5 ms) OFF;
- Composite Source Signal (CSS ), described in annex B.
In the case of terminal equipment using technologies for which the test specifications in this annex are not
suitable to prove conformance to this I-ETS, equivalent evaluation methods can be used, cfr. subclause
A.1.5. The methods shall be documented by the supplier and evaluated by the test house.
All tests are to be carried out using only one type of test signal. The test signal shall be
...