1、 ETSI TR 103 138 V1.5.1 (2018-08) Speech and multimedia Transmission Quality (STQ); Speech samples and their use for QoS testing TECHNICAL REPORT ETSI ETSI TR 103 138 V1.5.1 (2018-08) 2 Reference RTR/STQ-00221m Keywords QoS, quality, speech ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex
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7、n extend to reproduction in all media. ETSI 2018. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are trademarks of ETSI registered for the benefit of its Members. 3GPPTM and LTETMare trademarks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partne
8、rs. oneM2M logo is protected for the benefit of its Members. GSMand the GSM logo are trademarks registered and owned by the GSM Association. ETSI ETSI TR 103 138 V1.5.1 (2018-08) 3 Contents Intellectual Property Rights 5g3Foreword . 5g3Modal verbs terminology 5g3Introduction 5g31 Scope 6g32 Referenc
9、es 6g32.1 Normative references . 6g32.2 Informative references 6g33 Abbreviations . 7g34 Devices and network access . 7g34.1 Mobile devices . 7g34.2 ISDN/PSTN 8g34.3 Test scenarios . 8g34.3.1 General aspects . 8g34.3.2 Narrowband telephony and narrowband test scenario 8g34.3.3 Wideband telephony and
10、 super-wideband/fullband test scenario . 9g35 Speech samples 10g35.1 General aspects . 10g35.2 Pre-filtering of speech signals 10g35.2.1 Emulation of handsets . 10g35.2.2 Filter for narrowband test scenarios 10g35.2.2.1 IRS send Filter 10g35.2.2.2 MSIN Filter. 11g35.2.2.3 Recommended filters to use
11、in narrowband mobile test scenarios 12g35.2.3 Filter for wideband and fullband telephony test scenarios 12g35.2.3.1 Filter for fullband signals 12g35.2.3.2 14 kHz bandpass . 12g35.2.3.3 Recommendation ITU-T P.341 . 12g35.2.3.4 Recommended filters to use in super-wideband mobile test scenarios . 13g3
12、5.2.4 Reference signals 13g35.3 Audio level . 13g35.3.1 Nominal level 13g35.3.2 Level adjustment with Recommendation ITU-T P.56 13g35.3.3 Input level at test devices 14g36 Scenarios 14g36.1 Narrowband-Measurement Land to Mobile . 14g36.2 Narrowband-Measurement Mobile to Land . 14g36.3 Mobile to Mobi
13、le 15g36.3.1 Narrowband 15g36.3.2 Wideband and super-wideband . 15g37 Synopsis . 16g3Annex A: Coefficients for the reconstruction lowpass filter 17g3Annex B: Bibliography 18g3Annex C: Speech Samples . 19g3C.1 Introduction 19g3C.2 Design. 19g3C.3 Example results 20g3ETSI ETSI TR 103 138 V1.5.1 (2018-
14、08) 4 C.4 Technical specification . 20g3History 22g3ETSI ETSI TR 103 138 V1.5.1 (2018-08) 5 Intellectual Property Rights Essential patents IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is
15、publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual 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
16、ETSI Web server (https:/ipr.etsi.org/). Pursuant to the ETSI IPR Policy, no investigation, including 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,
17、 or may become, essential to the present document. Trademarks The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners. ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no right t
18、o use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks. Foreword This Technical Report (TR) has been produced by ETSI Technical Committee
19、 Speech and multimedia Transmission Quality (STQ). Modal verbs terminology In the present document “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 provisi
20、ons). “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 to handy ins
21、tructions 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 V1.5.1 (2018-08) 6 1 Scope The present document introduces and explains the use and application of speech samples
22、to determine the objective listening quality (LQO) in narrowband (NB), wideband (WB), super-wideband (SWB) and fullband (FB) for different scenarios such as connections between fixed networks and mobile terminals. 2 References 2.1 Normative references Normative references are not applicable in the p
23、resent document. 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 referenced document
24、(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 the user with
25、 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 telephone-b
26、and 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 transforming P
27、.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 Recommendations P.86
28、2, P.862.1 and P.862.2“. i.8 Recommendation ITU-T P.863: “Perceptual objective listening quality prediction“. 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 frequencies“. i.11 Recommenda
29、tion ITU-T G.191: “Software tools for speech and audio coding standardization“. i.12 Recommendation ITU-T P.341: “Transmission characteristics for wideband digital loudspeaking and hands-free telephony terminals“. i.13 Recommendation ITU-T P.56: “Objective measurement of active speech level“. i.14 R
30、ecommendation ITU-T P.501: “Test signals for use in telephonometry“. ETSI ETSI TR 103 138 V1.5.1 (2018-08) 7 i.15 Recommendation ITU-T P.10/G100: “Vocabulary for performance, quality of service and quality of experience“. 3 Abbreviations For the purposes of the present document, the following abbrev
31、iations apply: AMR Adaptive Multi-Rate codec AMR-WB Adaptive Multi-Rate codec Wideband ASL Active Speech Level EFR Enhance Full Rate codec EVS Enhanced Voice Services, speech codec FB Fullband FIR Finite Impulse Response filter IRS Intermediate Reference SystemISDN Integrated Services Digital Networ
32、k LQO Listening Quality Objective MOS Mean Opinion Score MSIN Mobile Station Input filter NB Narrowband NTP Network Terminating Point OVL Overload point PBX Private Branch Exchange PC Personal Computer PCM Pulse Code Modulation PSTN Public Switched Telephone Network SWB Super-Wideband VoLTE Voice ov
33、er LTE WB Wideband 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 network testing. In end-to-end testing a test connection between two endpoints is established. This determines the access interfaces and devices
34、. 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 contributor to the overall quality measured in the test connection. Mobile devices do not have a standardized audio interface, neither digita
35、l 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 for audio insertion and capturing, the measurement equipment has to match to the devices headset connector in impedance and level. It has to
36、 be noted that in this setup the mobile devices are used in headset mode. Devices apply individual audio profiles, means individual settings in filtering, amplification and noise- and echo treatment for connected headphones or the use of the internal microphone. Often there is a third mode that appl
37、ies 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 connection emulates a user with a headphone (personal handsfree kit) connected by wire to the headphone connector. ETSI ETSI TR 103 138 V1.5.1
38、 (2018-08) 8 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 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 int
39、erface 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 interface module or PC card is usually accessed with a digitalized speech signal in PCM format. The format is preferably 16 bit or 13 bit linea
40、r 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 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 l
41、ocal loop, where the regular A-Law compression will be at the digital NTP or the PBX. Today, ISDN/PSTN channels are narrowband only. Thus, a transmission to an 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
42、gateway to the ISDN/PSTN. 4.3 Test scenarios 4.3.1 General aspects The analogue circuits of almost all mobile devices are able to process wideband or fullband speech. Whether a call is transmitting narrowband or wideband or above speech depends on the wideband coding capability of the phone, the net
43、work and call setup. The subscriber cannot control whether the phone connects in narrowband, in wideband or in super-wideband. The established channel determines the transmission bandwidth of the channel that can be narrowband, wideband, super-wideband or even fullband. 4.3.2 Narrowband telephony an
44、d 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 technical limit is given by the Nyquist frequency due to sampling at 4 kHz upper audio transmission limit; there is no limit at the
45、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 is applied to the signal. Usually, there is a bandpass that is wider than the traditional pass-band but still limiting at the lower an
46、d upper range. The actual transmission characteristic is depending on the phone manufacturer and the setting of the phone. There are no binding limits or characteristics. Testing narrowband is not tied to a narrowband channel. Narrowband testing means that the listening quality is estimated as liste
47、ning through a conventional handset, the objective quality model filters the signal with such a bandpass and compares the speech signal to an ideal narrowband reference signal too. This restriction to a narrowband bandpass is applied despite the fact of the signal bandwidth passed through the channe
48、l. 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.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 an
49、d 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 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 si
