Telecommunications technologies are evolving at a rapid pace. The old Public Switched Telephone Network (PSTN) is being replaced with wireless and voice over IP (VoIP) systems. This requires the service providers to offer their services on competitive prices, on one hand, and to ensure the interoperability of their services over hetero- geneous networks on the other. Added to this is the challenge of keeping up with the expectations of the clientele as regards quality of service (QoS). Thus to enable the successful deployment and functioning of a telecommunications network, it is equally important to estimate the speech quality as it may be perceived by the humans. The goal of this research was to derive superior non-intrusive speech quality esti- mation models. Model superiority was sought in a multi-objective sense: 1) enhance- ment of prediction accuracy of the derived models as compared to the previous ones. 2) model simplicity or parsimony was desired as it may enhance the computational efficiency. In this research this is achieved by employing a novel approach based on Genetic Programming (GP).
Existing wireless networks enable different important applications over IP based network such as public internet and Voice over Internet protocol is one of the important applications which have become a possible alternative to public switched telephone network (PSTN). This project investigates one of the time sensitive data applications on WiMAX i.e. VoIP. I carried on WiMAX because WiMAX networks provide advance features and protocols to support the Quality of service (QoS). This project also indicates about the impact of load and mobility on the voice calls. This book provides details about the Voice Over Internet Protocol (VoIP), Which includes types of VoIP calls, VoIP System and Components, VoIP Protocols, VoIP codecs and VoIP Quality of Service (QoS). It also provides detailed study of WiMAX including WiMAX Protocol Layer and WiMAX Quality Of Service(QoS)
Wireless local area networks (WLANs) have traditionally been used to transport only data, but are now being used to carry voice traffic as well as provided new combined voice and data services. Voice over WLANs also offers more flexibility than wired networks (changes to a WLAN don't require changes to installed wiring) and greater capacity than wired networks. This book provides a solid overview of voice over WLANs/VoIP (voice over internet protocol) technology, including voice coding, packet loss, delay and jitter, and echo control. It shows how to combine both WLAN and VoIP technology to create effective voice over WLAN systems. Gives complete details on integrating voice and data services on WLANs, including wide area networks. Explores quality of service (QoS) and security issues. Step-by-step descriptions of how to plan and implement voice over WLAN networks.
Long Term Evolution (LTE) is the 4th Generation mobile technology as specified by 3rd Generation Partnership Project (3GPP) standard. It has an Internet Protocol (IP) based architecture which can support downlink speeds as high as 100 Mbps. This enables reliable real time (live) video streaming on mobile devices.One of the most significant changes with LTE compared to current and earlier cellular systems is that it is aimed at an all IP network where only packet switching is supported. Voice call will no longer be using separate circuit switched channels. This book will cover the technology and architecture of LTE.In this book we have studied and analyzed the throughput and the delay performance characteristics of standard voice and video calls employing Hybrid Automatic Repeat request (HARQ) Schemes at the Medium Access Control (MAC) layer. Also emphasis has been laid on improving the Quality of Service (QoS) of voice and video transmissions LTE. This involves a detailed study of the LTE protocol stack delay, and MAC and TCP performance in the LTE network.
The most critical and difficult problem in speech analysis is reliable discrimination among Silence, Unvoiced and Voiced speech. Several methods have been proposed for making this three levels decision and most of them need Speech Activity Detection (SAD). In this study, we propose the Estimated Degree of Noise (EDON) to adjust the threshold of speech activity. To estimate the degree of noise, a function was previously prepared using the least-squares (LS) method, from the given (true) DON and the estimated parameter of DON. This parameter is obtained from the Auto-Correlation Function (ACF) of the noisy speech on a frame basis. Issues associated with this EDON for SAD approach are discussed, and experiments are done using the TIMIT database. Experimental result shows that using EDON improves the classification performance specially voiced and silent parts and the efficiency is compared with other existing published algorithms.
The Dinka people live in the recently born state of South Sudan. Their language, counting over two millions of speakers, has been studied with growing interest for its rich prosodic system, featuring phonological distinctions in tone, vowel length and voice quality. Dinka songs play an important role as social aggregators and as carriers of private and collective memory. In this book the author studies for the first time the production and perception of the voice quality distinction in songs. Starting from the results already yielded by the acoustic analysis of Dinka speech data (Luanyjang dialect), acoustic measurements are applied to song data in order to determine if and how the phonological distinction between modal and breathy voice quality is realized in songs. The perceptual dimension is assessed with a perception test, where listeners are asked to distinguish between the two types of phonation. The introductory chapters and the up-to-date extensive bibliography make this book not only a good starting point to know more about the definition and measurement of voice quality, but also as a quick and easy-to-read introduction to the fascinating complexity of Dinka.
Measuring the quality of IP network services that users are experiencing and maintaining their loyalty towards these services are the most important factors that service providers consider. The existing evaluation methods for calculating the Quality of Experience (QoE) are categorized into two groups named subjective and objective. The subjective approaches are expensive and time consuming. The focus of present book is on objective measurement of QoE for network services.
This book presents and discusses current IPTV technology. Internet Protocol television (IPTV) is a system through which internet television services are delivered using architecture and networking methods of the Internet Protocol Suite over a packet-switched network infrastructure. IPTV services may be classified into three main groups: live television, time-shifted programming, and video on demand. Generally, IPTV works on the TV with a set-top box that accesses channels, subscription services, on demand and other interactive multimedia services over a secure, end-to-end operator managed broadband IP data network with desired QoS to the public with a broadband Internet connection. This book discusses the IPTV architecture, network technologies, implementation of IPTV and different types of STBs that are in use with special reference to New Zealand. The standards, different business models, hardware and software of IPTV are also described.
Wi-Fi telephony is the latest, most cost effective, and clearest way of carrying voice data wirelessly. The great news is that it can be integrated seamlessly into the same infrastructures as currently used for computer and telephone data.The digital quality is far above current cellular technologies.This book will be among the first to discuss Session Initiation Protocol (SIP), Quality of Service (QoS), and interoperability in connection with Wi-Fi telephony. Security challenges are also presented and solved along these malleable wireless boundaries. In short, this book provides all the information necessary for effective, reliable, crystal clear Wi-Fi telephony service and implementation.*Using current telephone and computer infrastructure this technology can be implemented at low cost*The importance of Quality of Service (QoS) and security of Wi-Fi telephony is considered*Enhances the clarity of a call beyond a basic cellular phone using digital data transfer
Transmission Control Protocol (TCP) is the dominant protocol in modern communication networks, within which the issues of reliability, data flow and congestion control must be handled efficiently. TCP provides a communication service at an intermediate level between an application program and the Internet Protocol (IP). With the evolution of Third Generation (3G) toward 4G wireless network, such as Long Term Evolution-Advanced (LTE-Advanced) standard, the use of TCP becoming more important for reliable end-to-end data delivery. As TCP was initially designed for wired networks, the LTE-Advanced network performance will degrade due to signal impairment and heavily congested links. Consequently, the traditional TCP versions such as Tahoe, Reno, Newreno, Sack, Fack, and Vegas, could not fulfil LTE-Advanced requirements to support huge number of user equipment’s that need wider channel bandwidth, low latency, and the enormous data stream transferred over this network. The objective of this book is to investigate the significant role of TCP over LTE and LTE-Advanced networks and to analysing the opportunities to enhance the TCP variants to run efficiently over these networks.
The payment industry moved from magnetic stripe cards to the EMV protocol over the past few years. This change in technology led to a drastic reduction in fraud through electronic payments. In the UK alone, losses in the high street have been reduced by 67% from ?218.8m in 2004 to ?72.1m in 2009. On the other hand, losses due to fraud have increased over the Internet. The majority of Internet payment protocols do not take advantage of the security provided by EMV protocol and the smart card technology. Most of the transactions are protected by a simple username and a password. Furthermore, customers have no assurance that their credit card details are well protected by merchants processing and storing such details. This book proposes a new Internet payment protocol that leverages the security provided by the EMV protocol and applies it to the Internet commerce context. By using mobile devices with Near Field Communication technology support together with contactless credit cards, a customer can pay for goods bought over the Internet with the same level of security found in store.
This book shows the steps to design a routing protocol that handles the data delivery in wireless sensor networks which are employed to form the internet of things. The research started by exploring different approaches with their disadvantages which lead to add enhancements and move to next approach. The study aims to achieve perfect integration among different layers (application, Network, MAC) in order to reach the perfect solution of routing protocol.