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ITU Workshop on “Quality of Service and Quality of Experience of Multimedia Services in

Emerging Networks” (Istanbul, Turkey, 9-11 February 2015)

Overview of ITU-T Study Group 12 Recommendations on QoS and QoE

Joachim Pomy,Senior Engineer, Opticom GmbH Germany

Consultant@joachimpomy.de

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SG 12 Recommendations• E.420-E.479, E.800-E.859• G.100-series, except G.160-, G.180- and G.190-series• G.1000-series• I.350-series (including Y.1501/G.820/I.351), I.371,

I.378, I.381• P-series, except P.900-series• Y.1220-, Y.1530-, Y.1540-, Y.1560-series

http://www.itu.int/ITU-T/recommendations/index_sg.aspx?sg=12

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Work Programme (1/8)• Coordination of QoS/performance studies• Communications Quality of Service: A framework and definitions• Vocabulary for performance and quality of service• Mean Opinion Score (MOS) terminology• Transmission characteristics for wideband digital handset and headset telephones -

Inclusion of extended wideband terminals• Transmission characteristics for cordless and moblie digital terminals• Transmission characteristics for wideband digital loudspeaking and hands-free

telephony terminals - Inclusion of extended wideband terminals• Technical requirements and test methods for the universal wired headset or

headphone interface of digital mobile terminals• Narrowband hands-free communication in motor vehicles• Wideband hands-free communication in motor vehicles

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P.800.1 Relation between some MOS qualifiers

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Work Programme (2/8)• User interface requirements for automotive applications• Subsystem requirements for automotive speech services• Artificial ears• Calculation of loudness ratings for telephone sets• Use of head and torso simulator (HATS) for hands-free and handset terminal

testing• Bone conduction testing setup• Multiple test positions setup• Setups and testing techniques for terminal performance measurements with

background noise• Artificial voices• Speech processing devices for acoustic enhancement• Transmission characteristics and speech quality parameters of hands-free

terminals

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Typical development cycle for a car speakerphone hands-free system and applicability of clauses of Rec. P.1100

P.1110(09)_F6-1

A sample B sample C sample D sample

Research end Pre-development end Dev. B sample end Dev. C sample end Dev. D sample end PPAP

SOP

Typically HFT development for a new car

Application of the different clauses of this Recommendation

Part 8 digital interface Part 8 digital interface

Parts 11 and 12 HFT and SRWTEP parameters

Part 13 subjective car-to-car test

Part 10 microphone parametersWhat is covered by the various parts of the test Recommendation?Part 7: Covers test arrangements used within this Recommendation.Part 8: Covers non-mandatory objective measurements using a digital interface.Part 9: Covers test signals used within this Recommendation.Part 10: Covers non-mandatory objective measurements of the microphone or/and microphone system.Part 11: Covers mandatory objective measurements of the hands-free terminal (HFT).Part 12: Covers non-mandatory objective measurements of short-range wireless transmission enabled phone (SRWTEP).Part 13: Covers non-mandatory subjective evaluation of the hands-free terminal (HFT).

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Work Programme (3/8)• Test signals for use in telephonometry• Objective test methods for speech communication systems using complex test

signals• Methods for determining the ‘Objective Quality Number’ as overall quality value

for terminals• Applicability of psycho-acoustic models to HATS based setups for the benefit of

terminal testing• Setup signals for terminal with background noise• Subjective quality evaluation of telephone services based on spoken dialogue

systems• Subjective performance of active signal processing devices• Cultural/language/nationality dependence of subjective quality• Subjective evaluation of generic sound activity detectors• Multidimensional scaling quality assessment• Subjective assessment methods for music quality of narrowband and wideband

telephony

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Rating scales used in ITU-T P.806 subjective testing

methodology PQ Scales Description Scale Descriptors

Overall Scales

B-LVLDegradation due to the Level of

Background Noisehissing, rushing, roaring

P.MULTI Perceptual Quality Scales

S-FLTSlow-varying Degradation in the

Speech Signalfluttering, babbling,

discontinuous

S-RUF Fast-varying Degradation in the Speech Signal

rough, raspy, harsh

S-HFCDegradation of High-frequency Coloration in the Speech Signal

small, distant, thin

S-LFC Degradation of Low-Frequency Coloration in the Speech Signal

dull, muffl ed, smothered

Description

LOUD

OVRL

Overall Loudness in the Speech Signal + Background Noise

Overall Quality in the Speech Signal + Background Noise

B-VAR Degradation due to the Variability of the Background Noise

bubbling, intermittent, variable

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Work Programme (4/8)• Test methodology for web browsing and browser based applications• Subjective usability evaluation of speech-based or multimodal interactive

services• Q.7/12 defines test plans for tests of speech coders, and reports the test

results and analysis• E-model extension for non-handset user interfaces• E-model extension for speech processing devices• E-model update for conversational quality features• Mixed-band and beyond-wideband E-model• E-model for monitoring• Operational quality estimator• Perceptual approaches for multi-dimensional analysis• Perceptual objective noise reduction

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Test setup for Rec. P.1501 Quality of web browsing

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Work Programme (5/8)• Perceptual Objective Prediction of Speech Intelligibility• No-reference models for quality prediction• Subjective method for simulated conversation tests addressing audio and

audiovisual call quality• Effect of delays on the telemeeting quality• Use of auditory and visual cues for high-quality telemeetings• Overall telemeeting quality value (long term goal)• Quality implications and requirements for telemeeting and conferencing

services• Spatial audio meetings quality evaluation• Frequent updates of Appendices• Quality of Experience aspects of Multi Connection• End-to-end QoE aspects of tandemmed speech processing devices

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Rec. P.1301 Decision tree for Subjective quality evaluation of audio and audiovisual multiparty telemeetings

P.1301(12)_FA

Communicationmode including text / graphics

(e. g., webconferencing) ?

Yes

ITU-T P.1301 Annex B

No

Audio

Audio-visual

VideoCommunicationmode?

ITU-T P.1301 Annex C

Test mode= audio

Audio VideoTestmode?

Test mode= video

Audio-visual

Type ofquality?

Type ofquality?

Type ofquality?

Non-inter-active

Conver-sational

Conver-sational

Non-inter-active

Continue withFlowchart B

Continue withFlowchart C

Continue withFlowchart D

Continue withFlowchart E

Special testmethod required

Continue withFlowchart F

Conver-sational

Non-inter-active

Start

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Work Programme (6/8)• End-to-end performance for managed voice over LTE networks This

Recommendation describes the key aspects impacting end-to-end performance of managed voice applications over LTE networks.

• Definitions and associated measurement methods for user-centric parameters for call handling in cellular mobile voice service

• Mobile QoS• Supplement XX to ITU-T E.800-series Recommendations (Guidelines on Regulatory

Aspects of QoS)• End-user multimedia QoS categories• Network model for evaluating multimedia transmission performance over Internet

Protocol• Opinion model for video and audio streaming applications• QoE of Web-browsing• QoE requirements for multicast video streaming services• QoE requirements for telepresence services• Guidance for the use of P.1201 and P.1202 in operational contexts

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Rec. G.1010 – Model for user-centric QoS categories

T1213060-02

FaxErrortolerant

Conversationalvoice and video

Voice/video messaging

Streaming audioand video

Errorintolerant

Command/control(e.g. Telnet,

interactive games)

Transactions(e.g. E-commerce,WWW browsing,

Email access)

Messaging,Downloads

(e.g. FTP, still image)

Background(e.g. Usenet)

Interactive(delay <<1 s)

Responsive(delay ~2 s)

Timely(delay ~10 s)

Non-critical(delay >>10 s)

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Work Programme (7/8)• QoE-diagnostic information from P.120X.Y type models on technical causes of QoE

impairments• Integral index of quality for general service monitoring (per user-session); KQI definitions• Media-session QoE model (temporal pooling, long sequences; UDP- and TCP-based

streaming)• Parametric non-intrusive assessment of audiovisual progressive download, considering

stalling/re-buffering & quality integration• Parametric non-intrusive assessment of TCP-based multimedia streaming quality, considering

adaptive streaming• In-service non-intrusive measurement device – Voice service measurements• Analysis and interpretation of INMD voice-service measurements• Conformance testing for voice over IP transmission quality assessment models• Conversational model• Framework for invoking diagnostic functions• Voice Service Diagnosis Framework

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Rec. G.1029 - Voice Service Diagnosis Framework

Framework for mapping diagnostic parameters to root-cause parameters (Work Item 2)

Framework for invoking diagnostic functions (Work Item 1)

QoE/QoS Diagnostic parameters

QoE/QoS Root-cause analaysis

application

QoE/QoS Decision

parameters

Decision process

Diagnostic parameter to root-cause mapping

Invocation

QoE/QoS Root-cause

analysis parameters

Remedial action

network

Terminals

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Work Programme (8/8)• Technical cause analysis• Buffer models for development of client performance metrics• Hand-over performance among multiple access networks• Internet protocol data communication service – IP packet transfer and

availability performance parameters• Network performance objectives for IP-based services• Measurements in IP networks for inter-domain performance assessment• Ethernet frame transfer and availability performance• Ethernet service activation test methodology• Home network performance parameters• Proposed Appendices for Y.1566 : QoS mapping and interworking between

Ethernet, IP and MPLS

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Cannot find your Topic ?

• Work in ITU-T is contribution driven !• It is up to Y O U !!!!!• Next Meeting of Study Group 12– 5 – 14 May 2015 in

Geneva (Switzerland)– Deadline for Contributions• 22 April 2015

– http://www.itu.int/net/ITU-T/ddp/Default.aspx?groupid=T13-SG12

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Any questions ?

Joachim Pomyconsultant@joachimpomy.de