Fundamentals of Voice-Quality Engineering in Wireless Networks
Dr Avi Perry
Network operators are faced with the challenge of maximizing the quality of voice transmissions in wireless communications without impairing speech or data transmission. This book provides a comprehensive survey of voice quality algorithms, features, interactions, and trade-offs, at the device and system levels. Using a practitioner rather than algorithm-designer angle, this book is unique. The book elaborates on the root cause of impairments and ways for resolving them, as well as methodologies for measuring and quantifying voice quality before and after applying the remedies. A 'troubleshooting and case studies' chapter provides a useful approach to identifying and solving network impairments. Avoiding complex mathematics, the approach is based on real and sizable field experience supported by scientific and laboratory analysis. This title is suitable for practitioners in the wireless communications industry and graduate students in electrical engineering. Further resources, including a range of audio examples are available online at www.cambridge.org/9780521855952.
• A trouble-shooting and case studies section provides a useful approach to identifying and solving network impairments
• Audio recordings, available on-line (www.cambridge.org/9780521855952), enhance understanding by presenting a physical illustration of the issues
• Written from a practitioner rather than algorithm-design perspective, the issues are covered using logical reasoning and not complicated mathematics, making the book accessible to product managers, office managers, and sales, marketing and purchasing agents
Table of Contents
Introduction; Part I. Voice Quality Foundations: 1. An overview of voice coding architectures in wireless communications; 2. Quantitative assessment of voice quality; Part II. Applications: 3. Electrical echo and echo cancellation; 4. Acoustic echo and its control; 5. Noisy ambience, mobility, and noise reduction; 6. Speech level control; Part III. Wireless Architectures: 7. Mobile-to-mobile stand-alone VQS architectures and their implications on data communications; 8. The VQS evolution to 3G; Part IV. A Network Operator Guide for Selecting, Appraising, and Testing VQS: 9. A network operator guide to testing and appraising voice quality systems; 10. Service provider's system, management, and delivery, requirements; 11. Making economically sound investment decisions concerning voice quality systems; Part V. Managing the Network: 12. Trouble shooting and case studies; Part VI. Afterthoughts and Some Fresh Ideas: 13. Tracer probe; 14. My sound; 15. A procedure for evaluating and contrasting new wireless codecs performance with and without VQS; 16. The theory of sleep; Part VII. Recordings: 17. Audio illustrations; Glossary of common voice quality systems terminology; Abbreviations.