1、 ETSI ES 202 765-2 V1.2.1 (2014-05) Speech and multimedia Transmission Quality (STQ); QoS and network performance metrics and measurement methods; Part 2: Transmission Quality Indicator combining Voice Quality Metrics ETSI Standard ETSI ETSI ES 202 765-2 V1.2.1 (2014-05)2Reference RES/STQ-210 Keywor
2、ds performance, QoS, user, voice 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 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The present do
3、cument can be downloaded from: http:/www.etsi.org 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 exist
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7、ation of ETSI. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2014. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM and LTE ar
8、e Trade Marks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI ES 202 765-2 V1.2.1 (2014-05)3Contents Intellectual Property Rights 5g3Foreword . 5g31 Scope 6g32 Refer
9、ences 6g32.1 Normative references . 6g32.2 Informative references 6g33 Abbreviations . 7g34 Introduction 8g35 Measurement type 10g36 Voice quality scale . 10g37 List of indicators . 10g37.1 Post Dialling Delay 10g37.2 Media establishment delay . 11g37.3 Unsuccessful call ratio 11g37.4 Premature rele
10、ase probability . 11g37.5 Level of active speech signal at reception 12g37.6 Noise level at reception 12g37.7 Noise to signal ratio at reception 13g37.8 Speech signal attenuation (or gain) after transmission . 13g37.9 Talker echo delay . 14g37.10 Talker echo attenuation 15g37.11 Listening speech qua
11、lity . 16g37.12 Listening speech quality stability . 18g37.13 End-to-end delay 19g37.14 End-to-end delay variation . 20g37.15 Frequency responses at the reception . 21g38 Measurement frequency . 21g39 Duration of test calls. 21g310 Measurement configurations 22g310.1 VoIP services 22g310.2 VoIP serv
12、ices in triple play context 22g311 Measurement locations and their distribution 22g311.1 Measurement location requirements . 22g311.2 Method to determine measurement locations . 23g312 Results presentation 24g312.1 One-view visualization of performances 24g312.1.1 Pie diagram with all indicators . 2
13、4g312.1.2 Pie diagram with mandatory indicators 25g312.2 Non-compliant limits for result visualization . 25g313 Publication of the results 26g3Annex A (normative): Indicator stability formulation . 27g3A.1 Presentation 27g3A.2 Formulation 27g3A.3 Graphic illustration of the formulation . 28g3A.4 Som
14、e examples of stability indicator calculated on Listening Speech Quality 30g3ETSI ETSI ES 202 765-2 V1.2.1 (2014-05)4Annex B (normative): Calibration to take into account the frequency response of transducers . 32g3B.1 Method presentation . 33g3B.1.1 Sending . 33g3B.1.2 Sending . 33g3B.1.3 Global co
15、mmunication . 33g3B.1.4 Applications . 33g3Annex C (informative): Echo presentation 34g3C.1 Talker echo . 34g3C.2 Listener echo 34g3Annex D (informative): Examples of measurement point distribution . 35g3D.1 Example of France 35g3D.2 Example of Switzerland . 36g3History 39g3ETSI ETSI ES 202 765-2 V1
16、.2.1 (2014-05)5Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intell
17、ectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/ipr.etsi.org). Pursuant to the ETSI IPR Policy, no investigation, includin
18、g IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This ETSI Standard (ES) has been produc
19、ed by ETSI Technical Committee Speech and multimedia Transmission Quality (STQ). The present document is part 2 of a multi-part deliverable covering the QoS and network performance metrics and measurement methods as identified below: EG 202 765-1: “General considerations“; ES 202 765-2: “Transmissio
20、n Quality Indicator combining Voice Quality Metrics“; EG 202 765-3: “Network performance metrics and measurement methods in IP networks“; ES 202 765-4: “Indicators for supervision of Multiplay services“. ETSI ETSI ES 202 765-2 V1.2.1 (2014-05)61 Scope The present document aims at identifying and def
21、ining indicators and methodologies for a use in a context of end-user quality characterization and supervision of voice telephony services. In this context the measurements and metric determinations are performed by analysing signals accessible on user-end services and not on the network. In order t
22、o mirror the reality in terms of access to the services at the user-end, measurements and analyses are performed on electrical signals by excluding the electro-acoustic part of the end equipment, however the probe adaptation to the electric interface of the end user equipment takes into account the
23、electro-acoustic characteristics of this terminal. All the indicators presented and defined in the present document are objective indicators obtained by instrumental measurement methods. 2 References References are either specific (identified by date of publication and/or edition number or version n
24、umber) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the reference document (including any amendments) applies. Referenced documents which are not found to be publicly available in the expected location might be found at
25、http:/docbox.etsi.org/Reference. NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee their long term validity. 2.1 Normative references The following referenced documents are necessary for the application of the present document. Not applica
26、ble. 2.2 Informative references The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. i.1 Recommendation ITU-T P.800: “Methods for subjective determination of transmission quality“. i.2 Reco
27、mmendation ITU-T P.862: “Perceptual evaluation of speech quality (PESQ): An objective method for end-to-end speech quality assessment of narrow-band telephone networks and speech codecs“. i.3 Recommendation ITU-T P.862.1: “Mapping function for transforming P.862 raw result scores to MOS-LQO“. i.4 Re
28、commendation ITU-T P.862.3: “Application guide for objective quality measurement based on Recommendations P.862, P.862.1 and P.862.2“. i.5 Recommendation ITU-T P.800.1: “Mean Opinion Score (MOS) terminology“. i.6 Recommendation ITU-T E.800: “Terms and definitions related to quality of service and ne
29、twork performance including dependability“. i.7 Recommendation ITU-T E.845: “Connection accessibility objective for the international telephone service“. ETSI ETSI ES 202 765-2 V1.2.1 (2014-05)7i.8 ETSI EG 201 769: “Speech Processing, Transmission and Quality Aspects (STQ); QoS parameter definitions
30、 and measurements; Parameters for voice telephony service required under the ONP Voice Telephony Directive 98/10/EC“. i.9 Recommendation ITU-T P.56: “Objective measurement of active speech level“. i.10 Recommendation ITU-T O.41: “Psophometer for use on telephone-type circuits“. i.11 Recommendation I
31、TU-T G.131: “Talker echo and its control“. i.12 Recommendation ITU-T G.168: “Digital network echo cancellers“. i.13 Recommendation ITU-T G.114: “One-way transmission time“. i.14 Recommendation ITU-T P.505: “One-view visualization of speech quality measurement results“. i.15 ETSI EG 201 377 (all part
32、s): “Speech and multimedia Transmission Quality (STQ); Specification and measurement of speech transmission quality“. i.16 Recommendation ITU-T H.323: “Packet-based multimedia communications systems“. i.17 Recommendation ITU-T H.225.0: “Call signalling protocols and media stream packetization for pa
33、cket-based multimedia communication systems“. i.18 Recommendation ITU-T P.50: “Artificial voices“. i.19 Recommendation ITU-T P.501: “Test signals for use in telephonometry“. NOTE: This Recommendation includes an electronic attachment containing test signals for telephonometry applications. i.20 ETSI
34、 TR 102 506: “Speech and multimedia Transmission Quality (STQ); Estimating Speech Quality per Call“. i.21 Recommendation ITU-T P.863: “Perceptual objective listening quality assessment“. i.22 Recommendation ITU-T P.863.1: “Application Guide for Recommendation ITU-T P.863“. i.23 Recommendation ITU-T
35、P.800.2: “Mean opinion score interpretation and reporting“. 3 Abbreviations For the purposes of the present document, the following abbreviations apply: ADSL Asymmetrical Digital Subscriber Line ATA Analog Telephone Adapter BAS Broadband Access DSLAM Digital Subscriber Line Access Multiplexer GPS Gl
36、obal Positioning SystemGSM Global System for Mobile communications HATS Head And Torso Simulator IP Internet Protocol IPTV Internet Protocol Television ISDN Integrated Services Digital Network ITU-T International Telecommunication Union - Telecommunication standardization sector MGCP Media Gateway C
37、ontrol Protocol MOS Mean Opinion Score MOS-LQON Mean Opinion Store-Listening Quality Objective Narrow-band MOS-LQOSW Mean Opinion Store-Listening Quality Objective Super Wide band mV millivolt PC Personal Computer PDD Post Dialling Delay PESQ Perceptual Evaluation of Speech Quality PSTN Public Switc
38、hed Telephone Network ETSI ETSI ES 202 765-2 V1.2.1 (2014-05)8RTP Real Time Protocol SIP Session Initiation Protocol UMTS Universal Mobile Telecommunications Service VoIP Voice over Internet Protocol 4 Introduction The assessment of transmission quality based on voice quality metrics is already addr
39、essed in several standards at ETSI (e.g. EG 201 377 i.15 series) and elsewhere (mostly Recommendations ITU-T from the P and G series). These different documents address the measurement methodologies in terms of metrics, threshold, data acquisition or modelling of subjective opinion. The objective of
40、 the present document is to complement this material with practical requirements of use in the context of service verification and benchmark on a large and representative scale from the point of view of the end-users or of the regulatory authorities. This has been made necessary by the current or re
41、cent evolutions of the telecommunication sector: the competitive environment, in particular in voice services, where public protocols with high quality services have been replaced by a multitude of service providers with less guarantees, and where clients can very easily change their service provide
42、rs; the development of time varying quality in telecommunications, first in mobile offers (due to mobility and irregular network coverage), but now also for fixed services (mostly VoIP); the cohabitation, interaction and competition between services based on different technologies. Voice transmissio
43、n quality is now recognized as a differentiating factor, but it remains very difficult to quantify. To achieve the goal mentioned beforehand, there are several existing possibilities, not fully satisfying: Customer surveys. This is by far the cheapest way to assess the perception of end users. But t
44、he bias introduced by other factors such as price, as well as the fact that voice quality itself is rarely questioned, and if so not in a satisfactory way, make this source not really reliable (one never knows before a survey what are the problems encountered by end users). Pseudo-subjective tests,
45、with a few human testers assessing the quality of real links in several situations. This method has the major drawback of its lack of reproducibility, and is often applied without using the standard metrics and quality scales that can be found in standards like Recommendation ITU-T P.800 i.1. It is
46、also very long to run and not really cheap in the current competitive context where so many offers have to be assessed and it is not easily applicable in a context of quality changing over time. Objective tests. This is the most reliable way, although it is also based on sampling and can be very cos
47、tly in the case of a large deployment of probes or robots. The present document assumes that this last family of methodology answers the needs of a reliable comparison of telephony offers and is applied without combination with other methods. What matters the most is the point of view of the end-use
48、rs. What they perceive is not only the result of the transmission of a signal across a network; the processing of this signal at the sending and at the receiving sides also has big importance. Therefore, it seems obvious not to use passive network monitoring systems to assess end-to-end voice qualit
49、y, but rather active systems simulating the behaviour of the end users, including the terminal. A big advantage of such an approach is that it is highly technical and protocol agnostic, and therefore compliant with the expectations of users, which are not judging voice quality of PSTN, GSM or VoIP services following different criteria. A last important aspect addressed in the present document is the practical organization of measurement campaigns in order to get a realistic and reliable vision of the services as pe
