Overview

The quality of telecommunication voice services has become an important issue due to the evolving and liberalized market. With the advent of new technologies, however, a diversification takes place which makes it necessary to carefully plan and observe network quality. Speech communication quality - as it is perceived by the user or customer of a service - carries a multidimensional nature, a fact which must be reflected in its assessment and prediction with quality models. In this book a new schematic is developed which classifies different entities contributing to the quality of a service. It takes into account conversational user as well as service-related contributions. Starting from this concept, perceptively relevant constituents of speech communication quality are identified. A simulation model is developed and implemented, based on physical elements of the transmission configuration. It allows the perceptively most relevant parameters to be simulated, in real time and for the conversation situation. The book gives a valuable overview on assessment needed for reliably measuring the different quality dimensions. For the planning of telephone networks, quality models are presented which aim at predicting mouth-to-ear quality as it would be perceived by a user of the system. These models are an important tool for the planner of telecommunication networks, as they allow the expected quality to be estimated in advance, even before the network has been set up. Two well-known models (the SUBMOD and the E-model) are analyzed in more detail, with an emphasis on the psychoacoustic and psychophysical backgrounds. It turns out that model predictions are satisfactory for many types of degradations, but they can still be improved especially for new types of impairments. Proposals are made for quality model enhancement and combined approaches. Due to its 'handbook' character, this book is an invaluable source of background information for anyone working in the field of speech quality assessment as well as telephone network planning and operation.

Full Product Details

Author:   Sebastian Möller
Publisher:   Springer-Verlag New York Inc.
Imprint:   Springer-Verlag New York Inc.
Edition:   Softcover reprint of hardcover 1st ed. 2000
Dimensions:   Width: 15.50cm , Height: 1.40cm , Length: 23.50cm
Weight:   0.454kg
ISBN:  

9781441949899

ISBN 10:   1441949895
Pages:   244
Publication Date:   03 December 2010
Audience:   Professional and scholarly ,  Professional & Vocational
Format:   Paperback
Publisher's Status:   Active
Availability:   Out of stock  
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Table of Contents

1. Introduction.- 2. Considerations on Quality.- 1. Speech Quality.- 2. Quality in the Context of Telecommunications.- 3. Factors Influencing the Quality of Service.- 1. Perceptive Factors.- 2. Configuration of a Telephone Connection.- 3. Simulation of a Telephone Connection for Quality Assessment Purposes.- 4. Classification of Transmission and Service Parameters.- 5. Summary.- 4. Quality Assessment in Telecommunications.- 1. Choice of Test Subjects.- 2. Articulation and Intelligibility Tests.- 3. Listening-Only and Conversation Opinion Tests.- 4. Performance Tests.- 5. User Surveys.- 6. Usability Evaluation.- 7. Assessment of Cost-Related Factors.- 8. Scaling.- 9. Development of Conversation Test Scenarios.- 10. Classification of Assessment Methods.- 11. Summary.- 5. Models for Predicting Speech Comm. Quality and Service-Related Models.- 1. Mouth-to-Ear Models Using Parameters in the Frequ. Domain.- 2. Mouth-to-Ear Models Using Scalar Parameters.- 3. Instrumental Models for Single Transmission Aspects.- 4. Call Set-Up and Call Completion Models.- 5. Customer Behavior Models.- 6. Application and Classification of Prediction Models.- 7. Summary.- 6. Relations between Factors Governing the Quality of Service.- 1. ‘Relative’ Quality versus ‘Absolute’ Quality.- 2. References and Normalization.- 3. Assessment in Listening-Only and Conversation Tests.- 4. Expectation.- 5. Influence of the Cost Factor.- 6. Multidimensional Assessment of Voice Transmission Quality.- 7. Existence of an Integral “Psychological Quality Scale”.- 8. Summary.- 7. Quality of Prediction Models.- 1. Prediction for Single Perceptive Types of Impairment.- 2. Prediction for Combinations of Different Types of Impairment.- 3. Impairment Factor Principle for Low-Bitrate Codecs.- 4. Prediction ofFrequency Characteristics.- 5. Measurement of the Input Parameters.- 6. Accuracy of Quality Predictions, Limitations.- 7. Summary.- 8. Final Discussion and Conclusions.- Appendices.- A- Glossary.- B- Perceptive Characteristics Resulting from New Technologies.- 1. Impact of New Technologies and Equipment.- 2. Classification for Modeling Purposes.- C- Discussion of Articulation and Intelligibility Test Methodologies.- D- Graeco-Latin-Square Test Design.- E- SCT Scenarios.- 1. Examples of SCT Scenarios.- 2. Explanations of the SCT Dialog Structure Given to the Test Subjects.- F- Closing Questionnaire Given after Laboratory Tests.- G- E-Model Algorithm.- H- Test Conditions and Results.- 1. Test Conditions of the Isopreference Test.- 2. Relation between E-Model Predictions and Test Results.- 3. Comparison of SUBMOD Model Predictions and Test Results.

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