SIST ES 202 738 V1.8.2:2022

ETSI STANDARD
Speech and multimedia Transmission Quality (STQ);
Transmission requirements for narrowband
VoIP loudspeaking and handsfree terminals
from a QoS perspective as perceived by the user

2 ETSI ES 202 738 V1.8.2 (2022-05)

Reference
RES/STQ-302
Keywords
handsfree, loudspeaking, narrowband, quality,
speech, terminal, VoIP
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16

Siret N° 348 623 562 00017 - APE 7112B
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° w061004871

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
If you find a security vulnerability in the present document, please report it through our
Coordinated Vulnerability Disclosure Program:
https://www.etsi.org/standards/coordinated-vulnerability-disclosure
Notice of disclaimer & limitation of liability
The information provided in the present deliverable is directed solely to professionals who have the appropriate degree of
experience to understand and interpret its content in accordance with generally accepted engineering or
other professional standard and applicable regulations.
No recommendation as to products and services or vendors is made or should be implied.
No representation or warranty is made that this deliverable is technically accurate or sufficient or conforms to any law
governmental rule and/or regulation and further, no representation or warranty is made of merchantability or fitness
and/or
for any particular purpose or against infringement of intellectual property rights.
In no event shall ETSI be held liable for loss of profits or any other incidental or consequential damages.

Any software contained in this deliverable is provided "AS IS" with no warranties, express or implied, including but not
limited to, the warranties of merchantability, fitness for a particular purpose and non-infringement of intellectual property
rights and ETSI shall not be held liable in any event for any damages whatsoever (including, without limitation, damages
for loss of profits, business interruption, loss of information, or any other pecuniary loss) arising out of or related to the use
of or inability to use the software.
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2022.
All rights reserved.
ETSI
3 ETSI ES 202 738 V1.8.2 (2022-05)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
Introduction . 5
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 8
3 Definition of terms, symbols and abbreviations . 9
3.1 Terms . 9
3.2 Symbols . 10
3.3 Abbreviations . 10
4 General considerations . 11
4.1 Default Coding Algorithm . 11
4.2 End-to-end considerations . 11
5 Test equipment . 12
5.1 IP half channel measurement adaptor . 12
5.2 Environmental conditions for tests . 12
5.3 Accuracy of measurements and test signal generation . 12
5.4 Network impairment simulation . 13
5.5 Acoustic environment . 13
5.6 Influence of terminal delay on measurements . 13
6 Requirements and associated measurement methodologies . 14
6.1 Notes . 14
6.2 Test setup. 14
6.2.1 General . 14
6.2.2 Setup for terminal . 15
6.2.2.1 Hands-free measurements . 15
6.2.2.2 Measurements in loudspeaking mode . 19
6.2.3 Test signal levels . 19
6.2.3.1 Send. 19
6.2.3.2 Receive . 20
6.2.4 Setup of background noise simulation . 20
6.2.5 Setup for variable echo path . 21
6.3 Coding independent parameters . 21
6.3.1 Send frequency response . 21
6.3.2 Send Loudness Rating (SLR). 22
6.3.3 Mic mute . 23
6.3.4 Send distortion . 23
6.3.5 Out-of-band signals in send direction . 24
6.3.6 Send noise . 24
6.3.7 Terminal Coupling Loss weighted (TCLw) . 25
6.3.8 Stability loss. 25
6.3.9 Receive frequency response . 26
6.3.10 Receive Loudness Rating (RLR) . 28
6.3.11 Receive Distortion . 29
6.3.12 Out-of-band signals in receive direction . 30
6.3.13 Receive noise . 30
6.3.14 Double talk performance . 31
6.3.14.1 General . 31
6.3.14.2 Attenuation range in send direction during double talk A . 31
H,S,dt
6.3.14.3 Attenuation range in receive direction during double talk A . 32
H,R,dt
ETSI
4 ETSI ES 202 738 V1.8.2 (2022-05)
6.3.14.4 Detection of echo components during double talk . 33
6.3.14.5 Minimum activation level and sensitivity of double talk detection . 34
6.3.15 Switching characteristics . 34
6.3.15.1 Note . 34
6.3.15.2 Activation in send direction . 34
6.3.15.3 Silence suppression and comfort noise generation . 35
6.3.16 Background noise performance . 35
6.3.16.1 Performance in send direction in the presence of background noise . 35
6.3.16.2 Speech quality in the presence of background noise . 36
6.3.16.3 Quality of background noise transmission (with far end speech). 37
6.3.17 Quality of echo cancellation . 37
6.3.17.1 Temporal echo effects . 37
6.3.17.2 Spectral echo attenuation . 38
6.3.17.3 Occurrence of artefacts . 39
6.3.17.4 Variable echo path. 39
6.3.18 Variant impairments . 39
6.3.18.1 Clock accuracy send . 39
6.3.18.2 Clock accuracy receive .
...

SLOVENSKI STANDARD
01-september-2022
Kakovost prenosa govora in večpredstavnih vsebin (STQ) - Prenosne zahteve za
ozkopasovne zvočniške in prostoročne terminale VoIP glede na kakovost storitev
(QoS), kot jo dojema uporabnik
Speech and multimedia Transmission Quality (STQ) - Transmission requirements for
narrowband VoIP loudspeaking and handsfree terminals from a QoS perspective as
perceived by the user
Ta slovenski standard je istoveten z: ETSI ES 202 738 V1.8.2 (2022-05)
ICS:
33.050.01 Telekomunikacijska Telecommunication terminal
terminalska oprema na equipment in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

ETSI STANDARD
Speech and multimedia Transmission Quality (STQ);
Transmission requirements for narrowband
VoIP loudspeaking and handsfree terminals
from a QoS perspective as perceived by the user

2 ETSI ES 202 738 V1.8.2 (2022-05)

Reference
RES/STQ-302
Keywords
handsfree, loudspeaking, narrowband, quality,
speech, terminal, VoIP
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16

Siret N° 348 623 562 00017 - APE 7112B
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° w061004871

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
If you find a security vulnerability in the present document, please report it through our
Coordinated Vulnerability Disclosure Program:
https://www.etsi.org/standards/coordinated-vulnerability-disclosure
Notice of disclaimer & limitation of liability
The information provided in the present deliverable is directed solely to professionals who have the appropriate degree of
experience to understand and interpret its content in accordance with generally accepted engineering or
other professional standard and applicable regulations.
No recommendation as to products and services or vendors is made or should be implied.
No representation or warranty is made that this deliverable is technically accurate or sufficient or conforms to any law
governmental rule and/or regulation and further, no representation or warranty is made of merchantability or fitness
and/or
for any particular purpose or against infringement of intellectual property rights.
In no event shall ETSI be held liable for loss of profits or any other incidental or consequential damages.

Any software contained in this deliverable is provided "AS IS" with no warranties, express or implied, including but not
limited to, the warranties of merchantability, fitness for a particular purpose and non-infringement of intellectual property
rights and ETSI shall not be held liable in any event for any damages whatsoever (including, without limitation, damages
for loss of profits, business interruption, loss of information, or any other pecuniary loss) arising out of or related to the use
of or inability to use the software.
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2022.
All rights reserved.
ETSI
3 ETSI ES 202 738 V1.8.2 (2022-05)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
Introduction . 5
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 8
3 Definition of terms, symbols and abbreviations . 9
3.1 Terms . 9
3.2 Symbols . 10
3.3 Abbreviations . 10
4 General considerations . 11
4.1 Default Coding Algorithm . 11
4.2 End-to-end considerations . 11
5 Test equipment . 12
5.1 IP half channel measurement adaptor . 12
5.2 Environmental conditions for tests . 12
5.3 Accuracy of measurements and test signal generation . 12
5.4 Network impairment simulation . 13
5.5 Acoustic environment . 13
5.6 Influence of terminal delay on measurements . 13
6 Requirements and associated measurement methodologies . 14
6.1 Notes . 14
6.2 Test setup. 14
6.2.1 General . 14
6.2.2 Setup for terminal . 15
6.2.2.1 Hands-free measurements . 15
6.2.2.2 Measurements in loudspeaking mode . 19
6.2.3 Test signal levels . 19
6.2.3.1 Send. 19
6.2.3.2 Receive . 20
6.2.4 Setup of background noise simulation . 20
6.2.5 Setup for variable echo path . 21
6.3 Coding independent parameters . 21
6.3.1 Send frequency response . 21
6.3.2 Send Loudness Rating (SLR). 22
6.3.3 Mic mute . 23
6.3.4 Send distortion . 23
6.3.5 Out-of-band signals in send direction . 24
6.3.6 Send noise . 24
6.3.7 Terminal Coupling Loss weighted (TCLw) . 25
6.3.8 Stability loss. 25
6.3.9 Receive frequency response . 26
6.3.10 Receive Loudness Rating (RLR) . 28
6.3.11 Receive Distortion . 29
6.3.12 Out-of-band signals in receive direction . 30
6.3.13 Receive noise . 30
6.3.14 Double talk performance . 31
6.3.14.1 General . 31
6.3.14.2 Attenuation range in send direction during double talk A . 31
H,S,dt
6.3.14.3 Attenuation range in receive direction during double talk A . 32
H,R,dt
ETSI
4 ETSI ES 202 738 V1.8.2 (2022-05)
6.3.14.4 Detection of echo components during double talk . 33
6.3.14.5 Minimum activation level and sensitivity of double talk detection . 34
6.3.15 Switching characteristics . 34
6.3.15.1 Note . 34
6.3.15.2 Activation in send direction . 34
6.3.15.3 Silence suppression and comfort noise generation . 35
6.3.16 Background noise performance . 35
6.3.16.1 Performance in send direction in the presence of background noise . 35
6.3.16.2 Speech quality in the presence of background noise . 36
6.3.16.3 Quality of background noise transmission (with far end speech). 37
6.3.17 Quality of echo cancellation . 37
6.3.17.1 Temporal echo effects .
...