Although the existing layering infrastructure--used globally for designing computers, data networks, and intelligent distributed systems and which connects various local and global communication services--is conceptually correct and pedagogically elegant, it is now well over 30 years old has started create a serious bottleneck. Using Cross-Layer Techniques for Communication Systems: Techniques and Applications explores how cross-layer methods provide ways to escape from the current communications model and overcome the challenges imposed by restrictive boundaries between layers. Written exclusively by well-established researchers, experts, and professional engineers, the book will present basic concepts, address different approaches for solving the cross-layer problem, investigate recent developments in cross-layer problems and solutions, and present the latest applications of the cross-layer in a variety of systems and networks.

Adaptive techniques play a key role in modern wireless communication systems. The concept of adaptation is emphasized in the Adaptation in Wireless Communications Series through a unified framework across all layers of the wireless protocol stack ranging from the physical layer to the application layer, and from cellular systems to next-generation wireless networks. Adaptation and Cross Layer Design in Wireless Networks is devoted to adaptation in the data link layer, network layer, and application layer. The book presents state-of-the-art adaptation techniques and methodologies, including cross-layer adaptation, joint signal processing, coding and networking, selfishness in mobile ad hoc networks, cooperative and opportunistic protocols, adaptation techniques for multimedia support, self –organizing routing, and tunable security services. It presents several new theoretical paradigms and analytical findings which are supported with various simulation and experimental results. Adaptation in wireless communications is needed in order to achieve high capacity and ubiquitous communications. The current trend in wireless communication systems is to make adaptation dependent upon the state of the relevant parameters in all layers of the system. Focusing on simplified cross layer design approaches, this volume describes advanced techniques such as adaptive resource management, adaptive modulation and coding, 4G communications, QoS, diversity combining, and energy and mobility aware MAC protocols. The first volume in the series, Adaptive Signal Processing in Wireless Communications (cat no.46012) covers adaptive signal processing at the physical layer.

Rapid growth of video applications over wireless networks is overwhelming the wireless bandwidth. Since video applications demand large bandwidth and realtime transmission, supporting the rapidly increasing video traffic over the bandwidth-limited, error-prone, and time-varying wireless channels is very challenging. As a result, the video applications are likely to suffer packet losses over wireless networks which results in quality degradation. In this dissertation, we design a distortion prediction model for H.264/AVC compressed video streams, and use it for designing novel cross-layer protocols for enhancing the video quality by making more efficient use of the available wireless resources. The cumulative mean squared error (CMSE) is a widely used measure of video distortion. However, CMSE measurement is a time-consuming and computationally-intensive process which is not suitable for many video applications. A low-complexity and low-delay generalized linear model is proposed for predicting CMSE contributed by the loss of H.264 AVC encoded video slices. The model is trained over a video database by using a combination of video factors that are extracted during the encoding of the current frame, without using any data from future frames in the group of pictures (GOP). The slices are then prioritized within a GOP based on their predicted CMSE values. The accuracy of the CMSE prediction model is analyzed using cross-validation, analysis of variance, and correlation coefficients. The simulations are carried out to evaluate the performance of the CMSE prediction model for varying encoder configurations and bit rates of test videos. The CMSE slice prediction model is used to design an unequal error protection (UEP) scheme, using the rate-compatible punctured convolutional (RCPC) codes over wireless channels. This scheme provides protection to the video slices against the channel errors, based on their priority, in order to minimize the video distortion. An application of our slice prioritization is demonstrated by implementing a priority-aware slice discard scheme, where the low-priority slices are dropped from the router when the network experiences congestion. Additionally, the GOP-level slice prioritization is extended to the frame-level slice prioritization, and its performance is evaluated over the additive white Gaussian noise (AWGN) channels The idea of using slice CMSE prediction is extended to adapt the video packet size to the wireless channel conditions, in order to minimize the video distortion. A real-time, priority-aware joint packet fragmentation and error protection scheme for real-time video transmission over Rayleigh fading channels is presented. The fragment error rates (FERs) are simulated for a combination of different fragment sizes and RCPC code rates. These FERs are then used to determine the optimal fragment sizes and code rates for packets of each priority class by minimizing the expected normalized predicted CMSE per GOP in H.264 video bit stream. An improvement in the received video quality over the conventional and priority-agnostic packet fragmentation schemes is observed. Next, a cross-layer, priority-aware scheduling scheme for real-time transmission of multiple video applications over a time-varying channel is developed. Each video application considered has different characteristics such as user priority, latency, distortion, size, and encoding bit rate. A cost function is optimized to determine the scheduling order for video frames. The performance of our scheme is compared with that of the CMSE based scheme, where the frames are rank-ordered for transmission using its CMSE per bit values, and with the earliest deadline first (EDF) scheme in which each user takes turns to transmit a frame. A collaborative effort with other researchers and developed two additional cross-layer error protection schemes. In the first scheme, a cross layer UEP scheme that jointly assigned FEC at both the Application layer (using Luby Transform) and the Physical layer (using RCPC codes) for prioritized video transmission is developed. The video distortion function is minimized by using the genetic algorithm (GA). The performance of our scheme is evaluated for different channel SNR values. In the second UEP scheme, a framework that combined the RCPC codes and concatenated it with hierarchical quadrature amplitude modulation (QAM) is investigated. Employing RCPC codes and hierarchical modulation jointly resulted in greater flexibility as some parts of the data can be protected only by the hierarchical modulation while others may be protected by a low FEC code rate. The performance of the proposed scheme is compared to the standard 8-QAM with symmetric constellation.

This book provides a solid overview of mobile phone programming for readers in both academia and industry. Coverage includes all commercial realizations of the Symbian, Windows Mobile and Linux platforms. The text introduces each programming language (JAVA, Python, C/C++) and offers a set of development environments "step by step," to help familiarize developers with limitations, pitfalls, and challenges.

A comprehensive presentation of the video communication techniques and systems, this book examines 4G wireless systems which are set to revolutionise ubiquitous multimedia communication.4G Wireless Video Communications covers the fundamental theory and looks at systems’ descriptions with a focus on digital video. It addresses the key topics associated with multimedia communication on 4G networks, including advanced video coding standards, error resilience and error concealment techniques, as well as advanced content-analysis and adaptation techniques for video communications, cross-layer design and optimization frameworks and methods. It also provides a high-level overview of the digital video compression standard MPEG-4 AVC/H.264 that is expected to play a key role in 4G networks. Material is presented logically allowing readers to turn directly to specific points of interest. The first half of the book covers fundamental theory and systems, while the second half moves onto advanced techniques and applications. This book is a timely reflection of the latest advances in video communications for 4G wireless systems. One of the first books to study the latest video communications developments for emerging 4G wireless systems Considers challenges and techniques in video delivery over 4G wireless systems Examines system architecture, key techniques and related standards of advanced wireless multimedia applications Written from both the perspective of industry and academia

With the rapid evolution of multimedia communications, engineers and other professionals are generally forced to hoard a plethora of different texts and journals to maintain a solid grasp on essential ideas and techniques in the field. Wireless Multimedia Communications provides researchers and students with a primary reference to help readers take maximum advantage of current systems and uncover opportunities to propose new and novel protocols, applications, and services. Extract the Essentials of System Design, Analysis, Implementation A complete technical reference, the text condenses the essential topics of core wireless multimedia communication technologies, convergence, QoS, and security that apply to everything from networking to communications systems, signal processing, and security. From extensive existing literature, the authors distill the central tenets and primary methods of analysis, design, and implementation, to reflect the latest technologies and architectural concepts. The book addresses emerging challenges to inform the system standardization process and help engineers combat the high error rates and stringent delay constraints that remain a significant challenge to various applications and services. Keep Pace with Detailed Techniques to Optimize Technology The authors identify causes of information loss in point-to-point signal transmission through wireless channels, and then they discuss techniques to minimize that loss. They use examples that illustrate the differences in implementing various systems, ranging from cellular voice telephony to wireless Internet access. Each chapter has been carefully organized with the latest information to serve dual purposes as an easy-to-reference guide for professionals and as a principal text for senior-level university students.