The Effect of Dynamic Voice Codec Selection for Active Calls on Voice Quality

The Effect of Dynamic Voice Codec Selection for Active Calls on Voice Quality
Author: Jered Daniel Ast
Publisher:
Total Pages: 146
Release: 2007
Genre: Electronic dissertations
ISBN:
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[Author abstract] Converged IP networks seek to incorporate voice, data, and video on the same infrastructure. However, the integration of all types of traffic onto a single IP network has several advantages as well as disadvantages. While reducing cost and increasing mobility and functionality, VoIP may lead to reliability concerns, degraded voice quality, incompatibility, and end-user complaints due to changing network characteristics. Voice quality degrades considerably due to low bandwidth, high packet loss rates, high jitter, or if total end-to-end delay is greater than the ITU-T suggested 150ms. In order to ensure these strict requirements are met, the underlying network must deploy various schemes to ensure resource availability. This research proposes an adaptive codec selection mechanism which changes the voice encoding scheme in the middle of an active call based on the network conditions. The mechanism is mainly proposed for H.323 based systems and is intended to cause little to no effect on voice quality. The proposed mechanism involves establishing a three-way handshake process in mid-call to renegotiate station capabilities, making the switch at a determined sequence number in an RTP packet. The proposed mechanism ensures the voice continuity while switching codecs by filling the play out buffers appropriately. The effect of these changes on voice quality is determined using the objective E-model.

UMTS Network Planning, Optimization, and Inter-Operation with GSM

UMTS Network Planning, Optimization, and Inter-Operation with GSM
Author: Moe Rahnema
Publisher: John Wiley & Sons
Total Pages: 349
Release: 2008-04-15
Genre: Technology & Engineering
ISBN: 047082302X
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UMTS Network Planning, Optimization, and Inter-Operation with GSM is an accessible, one-stop reference to help engineers effectively reduce the time and costs involved in UMTS deployment and optimization. Rahnema includes detailed coverage from both a theoretical and practical perspective on the planning and optimization aspects of UMTS, and a number of other new techniques to help operators get the most out of their networks. Provides an end-to-end perspective, from network design to optimization Incorporates the hands-on experiences of numerous researchers Single authorship allows for strong coherency and accessibility Details the complete iteration cycle of radio link budgeting for coverage planning and dimensioning Rahnema demonstrates detailed formulation of radio capacity and coverage in UMTS, and discusses the tradeoffs involved. He presents complete link budgeting and iterative simulations for capacity and coverage planning, along with practical guidelines. UMTS Network Planning contains seventeen cohesive and well-organized chapters which cover numerous topics, including: Radio channel structures, radio channel models, parameters, model tuning Techniques for capacity and coverage enhancements Complete treatment of power control, handoffs and radio resource practical management processes and parameters Detailed coverage of TCP protocol enhancement for operation over wireless links, particularly UMTS Application of GSM measurements to plan and re-engineer for UMTS radio sites Guidelines for site co-location with GSM, the QOS classes, parameters and inter-workings in UMTS AMR voice codecs and tradeoffs, core and access network design, architectural evolution, and protocols Comprehensive discussion and presentation of practical techniques for radio performance analysis, trending, and troubleshooting Perfect for professionals in the field and researchers specializing in network enhancement. Engineers working on other air interfaces and next generation technologies will find many of the techniques introduced helpful in designing and deploying future wireless networks as well. Students and professionals new to the wireless field will also find this book to be a good foundation in network planning, performance analysis, and optimization.

Circuits, Signals, and Speech and Image Processing

Circuits, Signals, and Speech and Image Processing
Author: Richard C. Dorf
Publisher: CRC Press
Total Pages: 888
Release: 2018-10-03
Genre: Technology & Engineering
ISBN: 1351838067
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In two editions spanning more than a decade, The Electrical Engineering Handbook stands as the definitive reference to the multidisciplinary field of electrical engineering. Our knowledge continues to grow, and so does the Handbook. For the third edition, it has expanded into a set of six books carefully focused on a specialized area or field of study. Each book represents a concise yet definitive collection of key concepts, models, and equations in its respective domain, thoughtfully gathered for convenient access. Circuits, Signals, and Speech and Image Processing presents all of the basic information related to electric circuits and components, analysis of circuits, the use of the Laplace transform, as well as signal, speech, and image processing using filters and algorithms. It also examines emerging areas such as text-to-speech synthesis, real-time processing, and embedded signal processing. Each article includes defining terms, references, and sources of further information. Encompassing the work of the world's foremost experts in their respective specialties, Circuits, Signals, and Speech and Image Processing features the latest developments, the broadest scope of coverage, and new material on biometrics.

Speech and Audio Processing for Coding, Enhancement and Recognition

Speech and Audio Processing for Coding, Enhancement and Recognition
Author: Tokunbo Ogunfunmi
Publisher: Springer
Total Pages: 347
Release: 2014-10-14
Genre: Technology & Engineering
ISBN: 1493914561
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This book describes the basic principles underlying the generation, coding, transmission and enhancement of speech and audio signals, including advanced statistical and machine learning techniques for speech and speaker recognition with an overview of the key innovations in these areas. Key research undertaken in speech coding, speech enhancement, speech recognition, emotion recognition and speaker diarization are also presented, along with recent advances and new paradigms in these areas.

VoIP Handbook

VoIP Handbook
Author: Syed A. Ahson
Publisher: CRC Press
Total Pages: 471
Release: 2008-12-18
Genre: Technology & Engineering
ISBN: 1420070215
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The number of worldwide VoIP customers is well over 38 million. Thanks to the popularity of inexpensive, high-quality services, it's projected to increase to nearly 250 million within the next three years. The VoIP Handbook: Applications, Technologies, Reliability, and Security captures the state of the art in VoIP technology and serves as the comprehensive reference on this soon-to-be ubiquitous technology. It provides: A step-by-step methodology to evaluate VoIP performance prior to network implementation An invaluable overview of implementation challenges and several VoIP multipoint conference systems Unparalleled coverage of design and engineering issues such VoIP traffic, QoS requirements, and VoIP flow As this promising technology’s popularity increases, new demands for improved quality, reduced cost, and seamless operation will continue to increase. Edited by preeminent wireless communications experts Ahson and Illyas, the VoIP Handbook guides you to successful deployment.

GSM, GPRS and EDGE Performance

GSM, GPRS and EDGE Performance
Author: Timo Halonen
Publisher: John Wiley & Sons
Total Pages: 654
Release: 2004-04-02
Genre: Technology & Engineering
ISBN: 0470866950
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GSM, GPRS and EDGE Performance - Second Edition provides a complete overview of the entire GSM system. GSM (Global System for Mobile Communications) is the digital transmission technique widely adopted in Europe and supported in North America. It features comprehensive descriptions of GSM’s main evolutionary milestones - GPRS, (General Packet Radio Services) is a packet-based wireless communication service that promises data rates from 56 up to 114 Kbps and continuous connection to the Internet for mobile phone and computer users. AMR and EDGE (Enhanced Data GSM Environment), and such developments have now positioned GERAN (GSM/EDGE Radio Access Network) as a full 3G radio standard. The radio network performance and capabilities of GSM, GPRS, AMR and EDGE solutions are studied in-depth by using revealing simulations and field trials. Cellular operators must now roll out new 3G technologies capable of delivering wireless Internet based multimedia services in a competitive and cost-effective way and this volume, divided into three parts, helps to explain how: 1. Provides an introduction to the complete evolution of GSM towards a radio access network that efficiently supports UMTS services (GERAN). 2. Features a comprehensive study of system performance with simulations and field trials. Covers all the major features such as basic GSM, GPRS, EDGE and AMR and the full capability of the GERAN radio interface for 3G service support is envisaged. 3. Discusses different 3G radio technologies and the position of GERAN within such technologies. Featuring fully revised and updated chapters throughout, the second edition contains 90 pages of new material and features the following new sections, enabling this reference to remain as a leading text in the area: Expanded material on GPRS Includes IMS architecture (Rel’5) and GERAN (Rel’6) features Presents field trial results for AMR and narrowband Provides EGPRS deployment guidelines Features a new chapter on Service Performance An invaluable reference for Engineering Professionals, Research and Development Engineers, Business Development Managers, Technical Managers and Technical Specialists working for cellular operators

Multimedia: Advanced Teleservices and High-Speed Communication Architectures

Multimedia: Advanced Teleservices and High-Speed Communication Architectures
Author: Ralf Steinmetz
Publisher: Springer Science & Business Media
Total Pages: 468
Release: 1994-09-21
Genre: Computers
ISBN: 9783540584940
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This volume contains the proceedings of the Second International Workshop on Advanced Teleservices and High-Speed Communication Architectures (IWACA '94), held in Heidelberg, Germany in September 1994. The IWACA Workshop is a platform for the exchange among researchers and developers from both the multimedia applications and the high-speed telecommunication communities. The book presents revised versions of the 36 papers accepted for presentation at the workshop. They cover several aspects of multimedia applications and asynchronous transfer mode (ATM), and focus on ATM-LANs and ATM for the wide area high-performance network of the future.

Beyond VoIP Protocols

Beyond VoIP Protocols
Author: Olivier Hersent
Publisher: John Wiley & Sons
Total Pages: 284
Release: 2005-08-05
Genre: Technology & Engineering
ISBN: 0470023635
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In 1999-2000, VoIP (Voice-over-IP) telephony was one of the most successful buzzwords of the telecom bubble era. However, in 2001-2003, VoIP faced a very tough reality check. Now, manufacturers and service providers are drawing on what they have learnt from past experience in order to prepare to participate in the next major challenge faced by the telecommunications industry. This book offers a comprehensive overview of the issues to solve in order to deploy global revenue-generating effective "multimedia" services. Drawing on extensive research and practical deployment experience in VoIP, the authors provide essential advice for those seeking to design and implement a post-bubble VoIP network. Beyond VoIP Protocols: Understanding Voice Technology and Networking Techniques for IP Telephony Introduces the basics of speech coding and voice quality Demonstrates how quality of service may be built into the network and deals with dimensioning aspects, e.g. multipoint communications and how to model call seizures. Explores the potential of multicast to turn an IP backbone into an optimized broadcast medium Includes amply illustrated, state-of-the-art practical advice for formulating a complete deployment strategy A companion volume to "IP Telephony: Deploying VoIP Protocols", this book takes the reader a stage deeper into how to prepare the network and exploit VoIP technology to its full potential.

Fixed Mobile Convergence Handbook

Fixed Mobile Convergence Handbook
Author: Syed A. Ahson
Publisher: CRC Press
Total Pages: 442
Release: 2018-09-03
Genre: Technology & Engineering
ISBN: 1351834398
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Requirements for next generation networks (NGNs) are fueling an architectural evolution. Service providers are obliged to give users access to content anytime, anyhow, anywhere, on any device. This requires a converged infrastructure in which users across multiple domains can be served through a single unified domain and all network services and business units can be consolidated on a single IP infrastructure. The Fixed Mobile Convergence Handbook is a comprehensive guide to the design, implementation, and management of converged cellular/WiFi wireless networks. This book discusses how FMC is transforming technologies as multimedia ceases to be passively consumed and unidirectional—and becomes increasingly mobile, personalized and interactive. This book also describes ways to ensure that networks remain cost-effective, scalable, reliable, and secure in the face of constant technological evolution. This material encapsulates the state of FMC, covering everything from basic concepts to research-grade material and future directions. Addressing a broad range of topics, the handbook consists of 16 chapters authored by 44 experts from around the world. Subjects include: Femtocell network technology and applications Deployment modes and interference avoidance Architecture for power efficiency Conversational quality and network planning Design of SIP-based mobility management protocols Highly respected in their field, the authors anticipate the key issues and problems that FMC presents—from application inception and deployment to system interconnection and Quality of Service (QoS). Ideal for professional mobile technology designers and/or planners, researchers (faculty members and graduate students), this book provides specific salient features and information that will guide innovation in the 21st century and beyond. Syed Ahson is a senior software design engineer with Microsoft. Previously, he was a senior staff software engineer with Motorola, where he was a leading contributor in the creation of several iDEN, CDMA, and GSM cellular phones. Dr. Mohammad Ilyas is associate dean for research and industry relations at the College of Engineering and Computer Science at Florida Atlantic University, Boca Raton. A consultant to several national and international organizations, Dr. Ilyas is a member of both the IEEE and ASEE.