SIST ES 202 738 V1.8.1:2020

SLOVENSKI STANDARD
SIST ES 202 738 V1.8.1:2020
01-julij-2020
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 V1.8.1 (2020-05)
ICS:
33.050.01 Telekomunikacijska Telecommunication terminal
terminalska oprema na equipment in general
splošno
SIST ES 202 738 V1.8.1:2020 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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Intellectual Property Rights ................................................................................................................................ 5

Foreword ............................................................................................................................................................. 5

Modal verbs terminology .................................................................................................................................... 5

Introduction ........................................................................................................................................................ 5

1 Scope ........................................................................................................................................................ 6

2 References ................................................................................................................................................ 6

2.1 Normative references ......................................................................................................................................... 6

2.2 Informative references ........................................................................................................................................ 7

3 Definition of terms, symbols and abbreviations ....................................................................................... 8

3.1 Terms .................................................................................................................................................................. 8

3.2 Symbols .............................................................................................................................................................. 9

3.3 Abbreviations ..................................................................................................................................................... 9

4 General considerations ........................................................................................................................... 10

4.1 Default Coding Algorithm ................................................................................................................................ 10

4.2 End-to-end considerations ................................................................................................................................ 10

5 Test equipment ....................................................................................................................................... 11

5.1 IP half channel measurement adaptor ............................................................................................................... 11

5.2 Environmental conditions for tests ................................................................................................................... 11

5.3 Accuracy of measurements and test signal generation ..................................................................................... 11

5.4 Network impairment simulation ....................................................................................................................... 12

5.5 Acoustic environment ....................................................................................................................................... 12

5.6 Influence of terminal delay on measurements .................................................................................................. 12

6 Requirements and associated measurement methodologies ................................................................... 13

6.1 Notes ................................................................................................................................................................ 13

6.2 Test setup.......................................................................................................................................................... 13

6.2.1 General ........................................................................................................................................................ 13

6.2.2 Setup for terminal ....................................................................................................................................... 14

6.2.2.1 Hands-free measurements ..................................................................................................................... 14

6.2.2.2 Measurements in loudspeaking mode ................................................................................................... 18

6.2.3 Test signal levels ......................................................................................................................................... 18

6.2.3.1 Send....................................................................................................................................................... 18

6.2.3.2 Receive .................................................................................................................................................. 19

6.2.4 Setup of background noise simulation ........................................................................................................ 19

6.2.5 Setup for variable echo path ....................................................................................................................... 20

6.3 Coding independent parameters ....................................................................................................................... 20

6.3.1 Send frequency response ............................................................................................................................ 20

6.3.2 Send Loudness Rating (SLR)...................................................................................................................... 21

6.3.3 Mic mute ..................................................................................................................................................... 22

6.3.4 Send distortion ............................................................................................................................................ 22

6.3.5 Out-of-band signals in send direction ......................................................................................................... 23

6.3.6 Send noise ................................................................................................................................................... 23

6.3.7 Terminal Coupling Loss weighted (TCLw) ................................................................................................ 24

6.3.8 Stability loss................................................................................................................................................ 24

6.3.9 Receive frequency response ........................................................................................................................ 25

6.3.10 Receive Loudness Rating (RLR) ................................................................................................................ 27

6.3.11 Receive Distortion ...................................................................................................................................... 28

6.3.12 Out-of-band signals in receive direction ..................................................................................................... 29

6.3.13 Receive noise .............................................................................................................................................. 29

6.3.14 Double talk performance ............................................................................................................................ 30

6.3.14.1 General .................................................................................................................................................. 30

6.3.14.2 Attenuation range in send direction during double talk A .............................................................. 30

6.3.14.3 Attenuation range in receive direction during double talk A ......................................................... 31

6.3.14.4 Detection of echo components during double talk ................................................................................ 32

6.3.14.5 Minimum activation level and sensitivity of double talk detection ....................................................... 33

6.3.15 Switching characteristics ............................................................................................................................ 33

6.3.15.1 Note ....................................................................................................................................................... 33

6.3.15.2 Activation in send direction .................................................................................................................. 33

6.3.15.3 Silence suppression and comfort noise generation ................................................................................ 34

6.3.16 Background noise performance .................................................................................................................. 34

6.3.16.1 Performance in send direction in the presence of background noise ..................................................... 34

6.3.16.2 Speech quality in the presence of background noise ............................................................................. 35

6.3.16.3 Quality of background noise transmission (with far end speech).......................................................... 36

6.3.17 Quality of echo cancellation ....................................................................................................................... 36

6.3.17.1 Temporal echo effects ........................................................................................................................... 36

6.3.17.2 Spectral echo attenuation ...................................................................................................................... 37

6.3.17.3 Occurrence of artefacts ......................................................................................................................... 38

6.3.17.4 Variable echo path................................................................................................................................. 38

6.3.18 Variant impairments ................................................................................................................................... 38

6.3.18.1 Clock accuracy send .............................................................................................................................. 38

6.3.18.2 Clock accuracy receive ......................................................................................................................... 38

6.3.18.3 Send packet delay variation................................................................................................................... 39

6.3.19 Send and receive delay - round trip delay ................................................................................................... 39

6.4 Codec specific requirements............................................................................................................................. 41

6.4.1 Objective listening speech quality MOS-LQO in send direction ................................................................ 41

6.4.2 Objective listening speech quality MOS-LQO in receive direction............................................................ 42

6.4.3 Quality of jitter buffer adjustment .............................................................................................................. 44

Annex A (informative): Processing delays in VoIP terminals ............................................................ 46

Annex B (informative): Bibliography ................................................................................................... 49

History .............................................................................................................................................................. 50

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This ETSI Standard (ES) has been produced by ETSI Technical Committee Speech and multimedia Transmission

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

Traditionally, analogue and digital telephones were interfacing switched-circuit 64 kbit/s PCM networks. With the fast

growth of IP networks, terminals directly interfacing packet-switched networks (VoIP) are being rapidly introduced.

Such IP network edge devices may include specifically designed IP phones, soft phones or other devices connected to

the IP based networks, providing telephony service. Since the IP networks will be in many cases interworking with the

traditional PSTN and private networks, many of the basic transmission requirements have to be harmonised with

specifications for traditional digital terminals. However, due to the unique characteristics of the IP networks including

packet loss, delay, etc. new performance specification, as well as appropriate measurement methods, will have to be

developed. Terminals are getting increasingly complex. Advanced signal processing is used to address the IP specific

issues. Also, the VoIP terminals may use other than 64 kbit/s PCM (Recommendation ITU-T G.711 [7]) speech coding

The advanced signal processing of terminals is targeted to speech signals. Therefore, wherever possible speech signals

are used for testing in order to achieve mostly realistic test conditions and meaningful results.

The present document provides speech transmission performance requirements for narrowband VoIP loudspeaking and

NOTE: Requirement limits are given in tables, the associated curve when provided is given for illustration.

The present document provides speech transmission performance requirements for narrowband VoIP loudspeaking and

hands-free terminals; it addresses all types of IP based terminals, including wireless, softphones and group audio

DECT terminals are covered in ETSI EN 300 175-8 [i.6] and ETSI EN 300 176-2 [i.7].

In contrast to other standards which define minimum performance requirements it is the intention of the present

document to specify terminal equipment requirements which enable manufacturers and service providers to enable good

In addition to basic testing procedures, the present document describes advanced testing procedures taking into account

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

Referenced documents which are not found to be publicly available in the expected location might be found at

NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee

The following referenced documents are necessary for the application of the present document.

[1] ETSI 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

[2] ETSI EN 300 726: "Digital cellular telecommunications system (Phase 2+) (GSM); Enhanced Full

[3] ETSI TS 126 171: "Digital cellular telecommunications system (Phase 2+); Universal Mobile

Telecommunications System (UMTS); LTE; Speech codec speech processing functions; Adaptive

Multi-Rate - Wideband (AMR-WB) speech codec; General description (3GPP TS 26.171)".

[5] Recommendation ITU-T G.109: "Definition of categories of speech transmission quality".

[6] Recommendation ITU-T G.122: "Influence of national systems on stability and talker echo in

[7] Recommendation ITU-T G.711: "Pulse code modulation (PCM) of voice frequencies".

[8] Recommendation ITU-T G.723.1: "Dual rate speech coder for multimedia communications

[9] Recommendation ITU-T G.726: "40, 32, 24, 16 kbit/s Adaptive Differential Pulse Code

[10] Recommendation ITU-T G.729: "Coding of speech at 8 kbit/s using conjugate-structure

[11] Recommendation ITU-T G.729.1: "G.729-based embedded variable bit-rate coder: An 8-32 kbit/s

[12] Recommendation ITU-T O.41: "Psophometer for use on telephone-type circuits".

[16] Recommendation ITU-T P.79: "Calculation of loudness ratings for telephone sets".

[17] Recommendation ITU-T P.310: "Transmission characteristics for narrow-band digital handset and

[18] Recommendation ITU-T P.340: "Transmission characteristics and speech quality parameters of

[19] Recommendation ITU-T P.342: "Transmission characteristics for narrow-band digital

[21] Recommendation ITU-T P.502: "Objective test methods for speech communication systems using

[22] Recommendation ITU-T P.581: "Use of head and torso simulator for hands-free and handset

[23] IEC 61260-1: "Electroacoustics - Octave-band and fractional-octave-band filters - Part 1:

[25] ETSI TS 103 224: "Speech and multimedia Transmission Quality (STQ); A sound field

[26] Recommendation ITU-T P.863.1: "Application guide for Recommendation ITU-T P.863".

[27] Recommendation ITU-T P.863: "Perceptual objective listening quality prediction".

[28] ETSI ES 202 737: "Speech and multimedia Transmission Quality (STQ); Transmission

requirements for narrowband VoIP terminals (handset and headset) from a QoS perspective as

[29] Recommendation ITU-T P.1010: "Fundamental voice transmission objectives for VoIP terminals

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee

The following referenced documents are not necessary for the application of the present document but they assist the

[i.1] ETSI EG 202 425: "Speech Processing, Transmission and Quality Aspects (STQ); Definition and

[i.2] ETSI EG 202 396-3: "Speech and multimedia Transmission Quality (STQ); Speech Quality

NOTE: Information available at https://wiki.linuxfoundation.org/networking/netem.

[i.4] ETSI EG 201 377-1: "Speech and multimedia Transmission Quality (STQ); Specification and

measurement of speech transmission quality; Part 1: Introduction to objective comparison

[i.6] ETSI EN 300 175-8: "Digital Enhanced Cordless Telecommunications (DECT); Common

[i.7] ETSI EN 300 176-2: "Digital Enhanced Cordless Telecommunications (DECT); Test

artificial ear: device for the calibration of earphones incorporating an acoustic coupler and a calibrated microphone for

the measurement of the sound pressure and having an overall acoustic impedance similar to that of the median adult

codec: combination of an analogue-to-digital encoder and a digital-to-analogue decoder operating in opposite directions

ear-Drum Reference Point (DRP): point located at the end of the ear canal, corresponding to the ear-drum position

freefield equalization: artificial head is equalized in such a way that for frontal sound incidence in anechoic conditions

freefield reference point: point located in the free sound field, at least in 1,5 m distance from a sound source radiating

NOTE: In case of a head and torso simulator (HATS) in the centre of the artificial head with no artificial head

group audio terminal: handsfree terminal primarily designed for use by several users which will not be equipped with

handsfree telephony terminal: telephony terminal using a loudspeaker associated with an amplifier as a telephone

HATS Hands-Free Reference Point (HATS HFRP): corresponds to a reference point "n" from Recommendation

ITU-T P.58 [15]: "n" is one of the points numbered from 11 to 17 and defined in table 6a of Recommendation ITU-T

NOTE: The HATS HFRP depends on the location(s) of the microphones of the terminal under test: the

appropriate axis lip-ring/HATS HFRP is to be as close as possible to the axis lip-ring/HFT microphone

Head And Torso Simulator (HATS) for telephonometry: manikin extending downward from the top of the head to

the waist, designed to simulate the sound pick-up characteristics and the acoustic diffraction produced by a median

loudspeaking function: function of a handset telephone using a loudspeaker associated with an amplifier as a

Mouth Reference Point (MRP): point located on axis and 25 mm in front of the lip plane of a mouth simulator

nominal setting of the volume control: setting which is closest to the nominal RLR

reordering: packet order changes during transfer over the network [i.5], packets arrive out of order at the receiver (i.e.