Produktbild: Speech Quality of VoIP

Speech Quality of VoIP Assessment and Prediction

167,99 €

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Beschreibung

Details

Einband

Gebundene Ausgabe

Erscheinungsdatum

01.11.2006

Verlag

John Wiley & Sons Inc

Seitenzahl

336

Maße (L/B/H)

25/17,4/2,5 cm

Gewicht

780 g

Auflage

1. Auflage

Sprache

Englisch

ISBN

978-0-470-03060-8

Beschreibung

Details

Einband

Gebundene Ausgabe

Erscheinungsdatum

01.11.2006

Verlag

John Wiley & Sons Inc

Seitenzahl

336

Maße (L/B/H)

25/17,4/2,5 cm

Gewicht

780 g

Auflage

1. Auflage

Sprache

Englisch

ISBN

978-0-470-03060-8

Herstelleradresse

Libri GmbH
Europaallee 1
36244 Bad Hersfeld
DE

Email: gpsr@libri.de

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Die Leseprobe wird geladen.
  • Produktbild: Speech Quality of VoIP
  • Preface.

    Introduction.

    Overview of the Book.

    1. Speech Quality in Telephony.

    1.1 Speech.

    1.1.1 Speech Acoustics.

    1.1.2 Speech Perception.

    1.2 Speech Quality.

    1.2.1 Definition of Quality.

    1.2.2 Speech Quality Assessment.

    1.2.3 Quality Elements.

    1.2.4 Speech Quality and Quality of Service.

    2. Speech Quality Measurement Methods.

    2.1 Auditory Methods.

    2.1.1 Utilitarian Methods.

    2.1.2 Analytical Methods.

    2.2 Instrumental Methods.

    2.2.1 Signal-based Models.

    2.2.2 Parameter-based Models.

    2.2.3 Monitoring Models.

    2.3 Speech Quality Measurement Methods: Summary.

    3. Quality Elements and Quality Features of VoIP.

    3.1 Speech Transmission Using the Internet Protocol.

    3.2 Overview of Quality Elements.

    3.3 Quality Elements and Related Features.

    3.3.1 Voice Activity Detection (VAD) .

    3.3.2 Codecs.

    3.3.3 Jitter.

    3.3.4 Delay.

    3.3.5 Packet Loss.

    3.3.6 Talker Echo.

    3.3.7 Listener Echo.

    3.3.8 Echo Cancellers.

    3.3.9 Loudness.

    3.3.10 Noise.

    3.3.11 Noise Suppression.

    3.3.12 Linear Distortion and Wide-band Transmission.

    3.3.13 User Interfaces.

    3.4 Quality Dimensions.

    3.5 Combined Elements and Combined Features.

    3.6 Listening and Conversational Features.

    3.7 Desired Nature.

    3.8 Open Questions.

    3.8.1 From Quality Elements to Quality Features: The E-model and VoIP.

    3.9 Quality Elements and Quality Features of VoIP: Summary.

    4. Time-Varying Distortion: Quality Features and Modelling.

    4.1 Microscopic Loss Behavior.

    4.1.1 Random Packet Loss.

    4.1.2 Dependent Packet Loss.

    4.2 Macroscopic Loss Behavior.

    4.2.1 Macroscopic Loss with Segments of Random Loss.

    4.2.2 Macroscopic Loss with Segments of Dependent Loss.

    4.3 Interactivity.

    4.4 Packet Loss and Combined Impairments.

    4.4.1 Additivity and Multidimensional Feature Space.

    4.4.2 Microscopic Loss Behavior: Random Packet Loss.

    4.4.3 Macroscopic Loss Behavior: 3-state Markov Loss.

    4.4.4 Model: Packet Loss and Combined Impairments.

    4.5 Time-Varying Distortion: Summary.

    5. Linear Distortion & Wideband Speech.

    5.1 Wideband Speech: Improvement over Narrowband.

    5.2 Bandpass-Filtered Speech.

    5.2.1 Listening Test.

    5.2.2 Parametric Impairment Model.

    5.3 Desired Nature.

    5.3.1 User Interfaces.

    5.3.2 Content.

    5.3.3 Summary.

    6. Summary and Conclusions.

    A. Aspects of Parametric Packet Loss Descriptions.

    A.1 4-state Markov Chain: Sojourn in Bad and Good State.

    A.2 Impact of other Quality Elements on Packet Loss.

    A.2.1 Forward Error Correction (FEC).

    A.2.2 Jitter and Jitter Buffer.

    B. Simulation of Quality Elements.

    B.1 PSTN and ISDN.

    B.1.1 Instrumental Verification.

    B.2 Mobile Networks.

    B.3 VoIP.

    B.3.1 Analog to ISDN Conversion.

    B.3.2 VoIP Gateways.

    B.3.3 IP Network Simulation.

    B.3.4 Instrumental Verification.

    B.4 Wideband Transmission.

    B.5 User Interfaces.

    B.5.1 Headsets.

    B.5.2 Wideband Handset and Hifi Phone.

    B.5.3 Bandpass Filters.

    B.5.4 Hands-Free Terminals (HFTs) .

    B.6 Test Rooms.

    B.7 Simulation of Quality Elements: Summary.

    C. Frequency Responses.

    C.1 Transmission Bandpass.

    C.1.1 Narrowband.

    C.1.2 Wideband.

    C.2 User Interfaces.

    C.2.1 Headsets.

    C.2.2 Wideband Handsets.

    D. Test Data Normalization and Transformation.

    D.1 Equivalent-QMethod.

    D.2 Method According to ITU-T Rec. P.833.

    D.3 Linear Transformation.

    E. E-model Algorithm.

    F. Interactive Short Conversation Test Scenarios (iSCTs).

    F.1 Example.

    G. Auditory Test Settings and Results.

    G.1 GSM: SCT and LOT.

    G.2 2-State Markov Loss: LOT.

    G.3 Random Loss: CT.

    G.3.1 Test Set-up.

    G.3.2 Test Procedure.

    G.3.3 Subjects.

    G.3.4 Details on Selected Results.

    G.4 3-State Markov Loss: CT.

    G.4.1 Test Set-Up.

    G.4.2 Test Procedure and Test Subjects.

    G.4.3 Details on Selected Results.

    G.5 Speech Sound Quality and Content.

    H. Modelling-Details.

    H.1 Time-Varying Distortions.

    H.1.1 Macroscopic Loss Behavior.

    Bibliography.