1、 ETSI TR 103 138 V1.3.1 (2015-03) Speech and multimedia Transmission Quality (STQ); Speech samples and their use for QoS testing floppy3TECHNICAL REPORT ETSI ETSI TR 103 138 V1.3.1 (2015-03) 2 Reference RTR/STQ-00203m Keywords QoS, quality, speech ETSI 650 Route des Lucioles F-06921 Sophia Antipolis
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7、xtend to reproduction in all media. European Telecommunications Standards Institute 2015. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM and LTE are Trade Marks of ETSI registered for the benefit of its Memb
8、ers and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI TR 103 138 V1.3.1 (2015-03) 3 Contents Intellectual Property Rights 4g3Foreword . 4g3Modal verbs terminology 4g3Introduction 4g31 Scope 5g32 References 5g32.1 Norm
9、ative references . 5g32.2 Informative references 5g33 Abbreviations . 6g34 Devices and network access . 6g34.1 Mobile devices . 6g34.2 ISDN/PSTN 7g34.3 Narrowband and wideband scenarios . 7g34.3.1 General aspects . 7g34.3.2 Narrowband telephony and narrowband test scenario 7g34.3.3 Wideband telephon
10、y and super-wideband test scenario . 8g35 Speech samples 9g35.1 General aspects . 9g35.2 Pre-filtering of speech signals 9g35.2.1 Emulation of handsets . 9g35.2.2 Filter for narrow-band test scenarios 9g35.2.2.1 IRS send Filter 9g35.2.2.2 MSIN Filter. 10g35.2.2.3 Recommended filters to use in narrow
11、band mobile test scenarios 11g35.2.3 Filter for wideband telephony test scenarios . 11g35.2.3.1 14 kHz bandpass . 11g35.2.3.2 Recommendation ITU-T P.341 . 11g35.2.3.3 Recommended filters to use in super-wideband mobile test scenarios . 11g35.2.4 Reference signals 12g35.3 Audio level . 12g35.3.1 Nomi
12、nal level 12g35.3.2 Level adjustment with Recommendation ITU-T P.56 12g35.3.3 Input level at test devices 12g36 Scenarios 13g36.1 Narrowband-Measurement Land to Mobile . 13g36.2 Narrowband-Measurement Mobile to Land . 13g36.3 Mobile to Mobile 14g36.3.1 Narrowband 14g36.3.2 Wideband 14g37 Synopsis .
13、15g3Annex A: Coefficients for the reconstruction lowpass filter 16g3Annex B: Bibliography 17g3Annex C: Speech Samples . 18g3C.1 Introduction 18g3C.2 Design. 18g3C.3 Example results 18g3C.4 Technical specification . 20g3History 21g3ETSI ETSI TR 103 138 V1.3.1 (2015-03) 4 Intellectual Property Rights
14、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: “Intellectual Property Rights (IPRs); Essential, or
15、 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, including IPR searches, has been carried out by ETSI
16、. 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 Technical Report (TR) has been produced by ETSI Technical Committee Speech and
17、 multimedia Transmission Quality (STQ). Modal verbs terminology 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
18、 of provisions). “must“ and “must not“ are NOT allowed in ETSI deliverables except when used in direct citation. Introduction Conducting drive test in multi technology environment presents a challenge to all parties. And the complexity and variance of the different scenarios need to be broken down t
19、o handy instructions for those who actually configure and conduct the measurements, such as Network Operators, Service Providers, Equipment Vendors and Regulatory Authorities. ETSI ETSI TR 103 138 V1.3.1 (2015-03) 5 1 Scope The present document introduces and explains the use and application of spee
20、ch samples to determine the objective listening quality (LQO) in narrowband (NB), wideband (WB) and super-wideband (SWB) for different scenarios such as connections between fixed networks and mobile terminals. 2 References 2.1 Normative references References are either specific (identified by date o
21、f 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 reference document (including any amendments) applies. Referenced documents which are not found to be publicly avail
22、able in the expected location might be found at 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. The following referenced documents are necessary for the application of the prese
23、nt document. Not applicable. 2.2 Informative references 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 referenc
24、e document (including any amendments) applies. NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee their long term validity. The following referenced documents are not necessary for the application of the present document but they assist th
25、e user with regard to a particular subject area. i.1 Recommendation ITU-T P.48: “Specification for an intermediate reference system“. i.2 Recommendation ITU-T P.800: “Methods for subjective determination of transmission quality“. i.3 Recommendation ITU-T P.830: “Subjective performance assessment of
26、telephone-band and wideband digital codecs“. i.4 Recommendation 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.5 Recommendation ITU-T P.862.1: “Mapping function for tra
27、nsforming P.862 raw result scores to MOS-LQO“. i.6 Recommendation ITU-T P.862.2: “Wideband extension to Recommendation P.862 for the assessment of wideband telephone networks and speech codecs“. i.7 Recommendation ITU-T P.862.3: “Application guide for objective quality measurement based on Recommend
28、ations P.862, P.862.1 and P.862.2“. i.8 Recommendation ITU-T P.863: “Perceptual objective listening quality assessment (POLQA)“. i.9 Recommendation ITU-T P.863.1: “Application Guide for the Recommendation ITU-T P.863“. i.10 Recommendation ITU-T G.711: “Pulse code modulation (PCM) of voice frequencie
29、s“. i.11 Recommendation ITU-T G.191: “Software tools for speech and audio coding standardization“. ETSI ETSI TR 103 138 V1.3.1 (2015-03) 6 i.12 Recommendation ITU-T P.341: “Transmission characteristics for wideband digital loudspeaking and hands-free telephony terminals“. i.13 Recommendation ITU-T P
30、.56: “Objective measurement of active speech level“. i.14 Recommendation ITU-T P.501: “Test signals for use in telephonometry“. 3 Abbreviations For the purposes of the present document, the following abbreviations apply: AMR Adaptive Multi-Rate codec AMR-WB Adaptive Multi-Rate codec Wide Band ASL Ac
31、tive Speech Level EFR Enhance Full Rate codec FIR Finite Impulse Response filter IRS Intermediate Reference SystemISDN Integrated Services Digital Network LQO Listening Quality Objective MOS Mean Opinion Score MSIN Mobile Station Input filter NB Narrow Band NTP Network Terminating Point OVL Overload
32、 point PBX Private Branch Exchange PC Personal Computer PCM Pulse Code Modulation PSTN Public Switch Telecommunication Network SWB Super Wide Band WB Wide Band 4 Devices and network access 4.1 Mobile devices There are only a few devices and access interfaces that play a role in end-to-end mobile net
33、work testing. In end-to-end testing a test connection between two endpoints is established. This determines the access interfaces and devices. The mobile device is not a pure access device to the mobile network. It contains complex components for speech processing and becomes therefore an important
34、contributor to the overall quality measured in the test connection. Mobile devices do not have a standardized audio interface, neither digital nor analogue. As common practice the headset connector of the mobile device is used as access interface for audio insertion and capturing. As a pre-condition
35、 for audio insertion and capturing, the measurement equipment has to match to the devices headset connector in impedance and level. It has to be noted that in this setup the mobile devices are used in headset mode. Devices apply individual audio profiles, means individual settings in filtering, ampl
36、ification and noise- and echo treatment for connected headphones or the use of the internal microphone. Often there is a third mode that applies when a handsfree loudspeaker set is connected. Since the audio processing in headphone mode is different from the use of internal microphone, such a test c
37、onnection emulates a user with a headphone (personal handsfree kit) connected by wire to the headphone connector. ETSI ETSI TR 103 138 V1.3.1 (2015-03) 7 4.2 ISDN/PSTN ISDN or (analogue) PSTN interfaces are not directly belonging to the mobile network but they are usually used as defined endpoint of
38、 the test connection. As access point to the ISDN or PSTN network a real consumer telephone device is not used but rather an ISDN or PSTN interface module as e.g. a PC card. It enables an electrical connection to the network for audio transmission and processes all the signalling information. The in
39、terface module or PC card is usually accessed with a digitalized speech signal in PCM format. The format is preferably 16 bit or 13 bit linear PCM sampled at 8 kHz or 16 kHz. Some interfaces expect 8 bit A-Law PCM that can be used in case of ISDN but is not recommended for PSTN, since it will cause
40、an additional A-Law compression step in the test connection. NOTE: The A-Law signal would be decompressed and fed as analogue signal in the local loop, where the regular A-Law compression will be at the digital NTP or the PBX. Today, ISDN/PSTN channels are narrow-band only. Thus, a transmission to a
41、n ISDN/PSTN end-point is always restricted to narrowband despite that the airlink can use AMR-WB. The transition to narrowband is part of the gateway to the ISDN/PSTN. 4.3 Narrowband and wideband scenarios 4.3.1 General aspects The analogue circuits of almost all mobile devices are able to process w
42、ideband or fullband speech. Whether a call is transmitting narrowband or wideband speech depends on the wideband coding capability of the phone, the network and call setup. The subscriber cannot control whether the phone connects in narrowband or in wideband. The established channel determines the t
43、ransmission bandwidth of the channel that can be narrowband, wideband, super-wideband or even fullband. 4.3.2 Narrowband telephony and narrowband test scenario The conventional narrowband or normal-band telephony is traditionally using a pass-band from 300 Hz to 3 400 Hz. In digital transmission the
44、 technical limit is given by the Nyquist frequency due to sampling at 4 kHz upper audio transmission limit; there is no limit at the lower boundary. Todays narrowband speech codecs as EFR or AMR are also able to encode an audio band up to 4 kHz. Despite that fact, in practice a dedicated filtering i
45、s applied to the signal. Usually, there is a bandpass that is wider than the traditional pass-band but still limiting at the lower and upper range. The actual transmission characteristic is depending on the phone manufacturer and the setting of the phone. There are no binding limits or characteristi
46、cs. Testing narrowband is not tied to a narrowband channel. Narrowband testing means that the listening quality is estimated as listening through a conventional handset, the objective quality model filters the signal with such a band-pass and compares the speech signal to an ideal narrowband referen
47、ce signal too. This restriction to a narrowband bandpass is applied despite the fact of the signal bandwidth passed through the channel. For testing a narrowband scenario using a mobile access device there are two setups: 1) Insertion of a signal that exceeds the traditional narrowband bandwidth, e.
48、g. 50 Hz to 3 800 Hz or even 50 Hz to 8 000 or 50 Hz to 14 000 Hz. In this case, the limitation of the signal is done by the device and the channel, while the device usually limits at most. At the receiving side, the recorded speech signal is compared to an ideal narrowband signal (at a bandwidth of
49、 50 Hz to 3 800 Hz). In this test case the filter characteristic of the mobile device used has a significant influence on the estimated quality, since all restrictions to the reference bandwidth are considered as degradation. The predicted MOS describes the overall quality as it is perceived by the particular device and the channel; the score is device dependent. 2) Insertion of a signal that emulates a traditional sending path that is close to the defined passband of 300 Hz to 3 400 Hz. Therefore the test speech signal is filtered with a bandpass
