In our increasingly mobile world the ability to access information on demand at any time and place can satisfy people's information needs as well as confer on them a competitive advantage. The emergence of battery-operated, low-cost and portable computers such as palmtops and PDAs, coupled with the availability and exploitation of wireless networks, have made possible the potential for ubiquitous computing. Through the wireless networks, portable equipments will become an integrated part of existing distributed computing environments, and mobile users can have access to data stored at information servers located at the static portion of the network even while they are on the move. Traditionally, information is retrieved following a request-response model. However, this model is no longer adequate in a wireless computing environment. First, the wireless channel is unreliable and the bandwidth is low compared to the wired counterpart. Second, the environment is essentially asymmetric with a large number of mobile users accessing a small number of servers. Third, battery-operated portable devices can typically operate only for a short time because of the short battery lifespan. Thus, clients are expected to be disconnected most of the time. To overcome these limitations, there has been a proliferation of research efforts on designing data delivery mechanisms to support wireless computing more effectively. Data Dissemination in Wireless Computing Environments focuses on such mechanisms. The purpose is to provide a thorough and comprehensive review of recent advances on energy-efficient data delivery protocols, efficient wireless channel bandwidth utilization, reliable broadcasting and cache invalidation strategies for clients with long disconnection time. Besides surveying existing methods, this book also compares and evaluates some of the more promising schemes.

In this book, the state-of-the-art and future vision of wireless communications is presented in the form of a number of new services. Wireless personal communications is clearly a different service than today's cellular radio or cordless telephone, but there is an evolutionary connection between the three services. This book addresses questions about what features of personal communication services (PCS) will be met by existing or enhanced digital cellular radio technology. The regulatory and standards aspects of wireless communications are currently in a crucial stage of their formulation. A section of the book is devoted to the opinions of representatives from regulatory agencies and standards organizations on the future of this critical area. One of the most intriguing questions about the future of wireless communications has to do with the choice of multiple access technique. The trade offs between time division multiple access (TDMA) and code division multiple access (CDMA) have been the topic of many a heated discussion amongst members of the wireless community. This book presents a thorough discussion of a number of the topics which are instrumental in making a fair comparison of TDMA and CDMA; these topics include: analytical performance evaluation techniques, capacity studies, equalization requirements, and shared spectrum comparisons. Many of the technologies associated with wireless personal communications are reaching the design stages. This book presents a number of alternatives for designs of both base stations and user terminals. Some of the key questions of equalization, control channel requirements, multi-path diversity and channel allocation strategies have been addressed. Invariably, system designs and performance are tied to the characteristics of the radio channel. This book introduces several novel techniques for predicting propagation and system performance in a variety of indoor and outdoor environments. These techniques include analytical as well as computer simulation algorithms for predicting signal strenghts and other channel parameters based on the local topographical features. This book serves as an excellent reference source and may be used as a text for advanced courses on wireless communications, cellular radio, or digital mobile radio.

The Integrated Services Digital Network (ISDN) represents the current position in about a hundred years of evolutionary growth of the worldwide telecommunications infrastructure. This evolution is by no means complete and the next few years will see the emergence of a "Broad-band" ISDN as the next stage of evolutionary development. It is important to appreciate the evolutionary nature of the telecommunications infrastructure if one is to properly understand much of the thinking that lies behind the current ISDN proposals. This book therefore begins with a number of chapters devoted to a study of the various developments which have eventually led to the concept of an integrated digital network. These include the development of digital transmission of speech using PCM and the development of digital switching techniques based on stored program control. The book then turns to a consideration of those features of the existing telecommunications network which need to be modified in order to make ISDN a realizable practicality. Of particular importance is the digitization of transmission over the links between the user and the local exchange. Next we look at the current practice and proposals for ISDN based on the technology presently in use in the telephone network. Finally, we look at the proposals for a broadband ISDN likely to become widely available by the turn of the century.

This graduate-level text lays out the foundation of DSP for audio and the fundamentals of auditory perception, then goes on to discuss immersive audio rendering and synthesis, the digital equalization of room acoustics, and various DSP implementations. It covers a variety of topics and up-to-date results in immersive audio processing research: immersive audio synthesis and rendering, multichannel room equalization, audio selective signal cancellation, multirate signal processing for audio applications, surround sound processing, psychoacoustics and its incorporation in audio signal processing algorithms for solving various problems, and DSP implementations of audio processing algorithms on semiconductor devices.

Wireless Local Loop (WLL) is now widely recognized as an economically viable technology for provision of telecommunication services to subscribers in sparsely populated as well as highly congested areas. However, the preparation of the business case, choice of a suitable technology, deployment planning, and radio and network system design for a WLL system depend on a range of technical and strategic planning variables. The scope of the book includes a systems level coverage of the following topics: Introduction to WLL systems; Fundamentals of Radio Systems; Key cellular and cordless technologies; WLL systems design system components and interfaces; WLL systems design radio aspects; Planning and deployment of WLL systems; Examples of commercially available WLL systems; and Broadband applications and services.

In response to the increasing interest in developing photonic switching fabrics, this book gives an overview of the many technologies from a systems designer's perspective. Optically transparent devices, optical logic devices, and optical hardware are all discussed in detail and set into a systems context. Comprehensive, up-to-date, and profusely illustrated, the work will provide a foundation for the field, especially as broadband services are more fully developed.

Rapid Prototyping of Application Specific Signal Processors presents leading-edge research that focuses on design methodology, infrastructure support and scalable architectures developed by the 150 million dollar DARPA United States Department of Defense RASSP Program. The contributions to this edited work include an introductory overview chapter that explains the origin, concepts and status of this effort. The RASSP Program is a multi-year DARPA/Tri-Service initiative intended to dramatically improve the process by which complex digital systems, particularly embedded signal processors, are designed, manufactured, upgraded and supported. This program was originally driven by military applications for signal processing. The requirements of military applications for real-time signal processing are typically more demanding than those of commercial applications, but the time gap between technology employed in advanced military prototypes and commercial products is narrowing rapidly. The research on methodologies, infrastructure and architectures presented in this book is applicable to commercial signal processing systems that are in design now, or will be developed before the end of the decade. Rapid Prototyping of Application Specific Signal Processors is a valuable reference for developers of embedded digital systems, particularly systems engineers for signal processing systems (such as digital TV, biomedical image processing systems and telecommunications) and for military contractors who are developing signal processing systems. This book will also be of interest to managers who are charged with responsibility for creating and maintaining environments and infrastructures for developing large embedded digital systems. The chief value for managers will be the defining of methods and processes that reduce development time and cost.

Steganography, a means by which two or more parties may communicate using "invisible" or "subliminal" communication, and watermarking, a means of hiding copyright data in images, are becoming necessary components of commercial multimedia applications that are subject to illegal use. This is a comprehensive survey of steganography and watermarking and their application to modern communications and multimedia. It helps the reader to understand steganography, the history of this previously neglected element of cryptography, the hurdles of international law on strong cryptographic techniques, and a description of the methods you can use to hide information in modern media. Included in this discussion is an overview of "steganalysis", methods which can be used to break stenographic communication. This resource also includes an introduction to and survey of watermarking methods, and discusses this method's similarities to and differences from steganography. The reader should gain a working knowledge of watermarking's pros and cons, and learn the legal implications of watermarking and copyright issues on the Internet.

The demand for wireless access to network services is growing in virtually all communications and computing applications. Once accustomed to unteathered opera tion, users resent being tied to a desk or a fixed location, but will endure it when there is some substantial benefit, such as higher resolution or bandwidth. Recent technolog ical advances, however, such as the scaling of VLSI, the development of low-power circuit design techniques and architectures, increasing battery energy capacity, and advanced displays, are rapidly improving the capabilities of wireless devices. Many of the technological advances contributing to this revolution pertain to the wireless medium itself. There are two viable media: radio and optical. In radio, spread-spectrum techniques allow different users and services to coexist in the same bandwidth, and new microwave frequencies with plentiful bandwidth become viable as the speed of the supporting low-cost electronics increases. Radio has the advantage of being available ubiquitously indoors and outdoors, with the possibility of a seam less system infrastructure that allows users to move between the two. There are unan swered (but likely to be benign) biological effects of microwave radiation at higher power densities. Optical communications is enhanced by advances in photonic devices, such as semiconductor lasers and detectors. Optical is primarily an indoor technology - where it need not compete with sunlight - and offers advantages such as the immediate availability of a broad bandwidth without the need for regulatory approval."

This book tells the story of the scientific talent and technological prowess of two nations that joined forces to connect themselves with a communications cable that would change the world. In 1855 an American visionary named Cyrus West Field, who knew nothing about telegraphy, sought to establish a monopoly on telegraphic revenues between North America and Europe. Field and the wealthy New Yorkers who formed the first Atlantic cable-laying company never suspected that spanning the vast and stormy Atlantic would require 11 years of frustration and horrific financial sacrifice. The enterprise would eventually engage some of the most brilliant minds in England, Scotland, and the United States, attracting men of science, men of wealth, and men of curiosity. Message time would be cut from more than four weeks to about two minutes. Such a feat would not have been possible without the massive ship the Great Eastern, designed by Isambard Kingdom Brunel, Britain's foremost engineer, or the financial backing of Thomas Brassey, the era's greatest builder of railroads. Despite four failed attempts and the enmity that developed between the Union and Great Britain during America's Civil War, Field never stopped urging his British friends to perfect a cable that could function in water as deep as two and a half miles. Without the unified effort of this small cadre of determined engineers, decades may have passed before submarine cables became reliable. This is the story of these men, their ships, and the technology that made it all possible. Behind the scenes were tough and worthy competitors who tried to beat them to the punch, adding a sense of urgency to their monumental task. Some called theAtlantic cable the greatest feat of the 19th century--with good reason. It perfected transoceanic communications and connected the world with circuits in the sea.

Herb Caen, a popular columnist for the San Francisco Chronicle, recently quoted a Voice of America press release as saying that it was reorganizing in order to "eliminate duplication and redundancy. " This quote both states a goal of data compression and illustrates its common need: the removal of duplication (or redundancy) can provide a more efficient representation of data and the quoted phrase is itself a candidate for such surgery. Not only can the number of words in the quote be reduced without losing informa tion, but the statement would actually be enhanced by such compression since it will no longer exemplify the wrong that the policy is supposed to correct. Here compression can streamline the phrase and minimize the em barassment while improving the English style. Compression in general is intended to provide efficient representations of data while preserving the essential information contained in the data. This book is devoted to the theory and practice of signal compression, i. e., data compression applied to signals such as speech, audio, images, and video signals (excluding other data types such as financial data or general purpose computer data). The emphasis is on the conversion of analog waveforms into efficient digital representations and on the compression of digital information into the fewest possible bits. Both operations should yield the highest possible reconstruction fidelity subject to constraints on the bit rate and implementation complexity."

In many international settings, regional economies are declining resulting in lowered opportunities for these communities. This result attacks the very fabric of cohesion and purpose for these regional societies, and increases social, health, economic and sustainability problems. Community informatics research, education and practice is an emerging area in many countries, which seeks to address these issues. The primary objective of Using Community Informatics to Transform Regions is to provide leaders, policy developers, researchers, students and community workers with successful strategies and principles of Community Informatics to transform regions. This book embraces an integrative cross-sectoral approach in the use of Community Informatics to increase both social and cultural capital as a means to increased sustainability for regional communities.

This book presents a selection of expanded research papers from the Fourth IFIP Workshop on the Performance Modelling and Evaluation of ATM Networks. It provides a fundamental source of reference on the latest research techniques and tools concerning ATM networks worldwide. A number of important topics are featured including: traffic modelling and characterisation, models of ATM switches, network management, high speed LANs and MANs and routing and optimization.

DSP System Design presents the investigation of special type of IIR polyphase filter structures combined with frequency transformation techniques used for fast, multi-rate filtering, and their application for custom fixed-point implementation. Detailed theoretical analysis of the polyphase IIR structure has been presented for two and three coefficients in the two-path arrangement. This was then generalized for arbitrary filter order and any number of paths. The use of polyphase IIR structures in decimation and interpolation is being presented and performance assessed in terms of the number of calculations required for the given filter specification and the simplicity of implementation. Specimen decimation filter designs to be used in Sigma-Delta lowpass and bandpass A/D converters are presented which prove to outperform other traditional approaches.

New frequency transformation types have been suggested for both real and complex situations. A new exact multi-point frequency transformation approach for arbitrary frequency choice has been suggested and evaluated. Applying such transformations to the existing filter allows to change their frequency response in an intuitive manner without the need of re-designing them, thus simplifying the designer's job when the specification changes during the prototyping and testing.

A new bit-flipping' algorithm has been developed to aid in filter design where the coefficient word length is constraint. Also, the standard Downhill Simplex Method (floating-point) was modified to operate with the constrained coefficient word length. Performance of both these advances is being evaluated on a number of filter cases. Novel decimation and interpolation structures have been proposed, which can be implemented very efficiently. These allow an arbitrary order IIR anti-aliasing filter to operate at the lower rate of the decimator/interpolator. Similar structures for polyphase IIR decimator/interpolator structures are being discussed too.

A new approach to digital filter design and implementation has been suggested which speeds-up silicon implementation of designs developed in Matlab. The Simulink block description is converted automatically into a bit-to-bit equivalent VHDL description. This in turn can be compiled, simulated, synthesized and fabricated without the need to go through the design process twice, first algorithmic/structural design and then the implementation.

The book is full of design and analysis techniques. It contains sufficient introductory material enabling non-expert readers to understand the material given in it.

DSP System Design may be of interest to graduate students, researchers, and professionals circuit designers, who would require fast and low-complexity digital filters for both single and multi-rate applications, especially those with low-power specification.

Designed for non-specialists, this easy-to-read new edition provides a comprehensive and coherent account of static electric phenomena and concepts based on a mathematical-physical approach. It has been updated to include new and expanded material ranging from charge decay to electrostatic measurements.

Predicting noise in RF systems at the design stage is extremely important. This book concentrates on developing noise simulation techniques for RF circuits. The authors present a novel approach of performing noise analysis for RF circuits.

Foundations of Digital Signal Processing: Theory, algorithms and hardware design starts by introducing the mathematical foundations of DSP, assuming little prior knowledge of the subject from the reader, and moves on to discuss more complex topics such as Fourier, Laplace and digital filtering. It provides detailed information on off-line, real-time and DSP programming, and guides the reader through advanced topics such as DSP hardware design, FIR and IIR filter design and difference equation manipulation. A CD accompanies the book. It provides the reader with programs that demonstrate equations discussed in the text and source codes to enable the reader to incorporate algorithms into their own DSP programs.

This volume contains the papers that have been presented at the Conference on Modeling and Control of Uncertain Systems held in Sopron, Hungary on September 3-7, 1990, organised within the framework of the activities of the System and Decision Sciences Program of IIASA - the International Institute for Applied Systems Analysis. The importance of the subject has drawn the attention of researchers all over the world since several years. In fact, in most actual applications the knowledge about the system under investigation presents aspects of uncertainty due to measurement errors or poor understanding of the rele vant underlying mechanisms. For this reason models that take into account these intrinsic uncertainties have been used and techniques for the analysis of their behavior as well as for their estimation and control have been devel oped. The main ways to deal with uncertainty consist in its description by stochastic processes or in terms of set-valued dynamics and this volume col lects relevant contributions in both directions. However, in order to avoid undesirable distinctions between these approaches, but on the contrary to stress the unity of ideas, we decided to organize the papers according to the alphabetical order of their authors. We should like to take this opportunity to thank IIASA for supporting the Conference and the Hungarian National Member Organization for the kind hospitality in Sopron. Finally we would like to express our gratitude to Ms. Donna Huchthausen for her valuable secretarial assistance. Vienna, February 20, 1991 GIOVANNI B."

This book provides an overview of positioning technologies, applications and services in a format accessible to a wide variety of readers. Readers who have always wanted to understand how satellite-based positioning, wireless network positioning, inertial navigation, and their combinations work will find great value in this book. Readers will also learn about the advantages and disadvantages of different positioning methods, their limitations and challenges. Cognitive positioning, adding the brain to determine which technologies to use at device runtime, is introduced as well. Coverage also includes the use of position information for Location Based Services (LBS), as well as context-aware positioning services, designed for better user experience.

Includes full color and black and white illustrations, This handbook is designed to aid electronic warfare and radar systems engineers in making general estimations regarding capabilities of systems. This handbook is sponsored by the NAVAIR Director of Electronic Warfare / Combat Systems. Chapters include: Fundamentals; Antennas; Radar Equations; Radar and Receiver Characteristics and Test; Microwave / RF Components; Electro-optics an IR; Aircraft Dynamics Considerations; Date Transfer Busses; Glossary; Abbreviations and Acronyms.

This is an in-depth study of the various technologies, services, and performance issues associated with networked multi-media systems. Prepared by 28 industry and academic leaders worldwide, this reference helps communications engineers understand the impact of fast-moving broadband communications technology on networked multimedia services, and how multimedia applications affect network design. It also provides research and development personnel with the practical information needed to support a wide variety of multimedia services, and how multimedia applications affect network design. In 11 chapters, the reader should learn of developments in network traffic control and also: wireless/wireline multimedia technology and applications; networked multimedia standards, requirements and planning/security issues; transmission, switching, and OA&M technologies; software architectures designed to support multimedia services; and the hypes and realities behind the next generation of multimedia.

Digital signal processing (DSP) is used in a wide range of applications such as speech, telephone, mobile radio, video, radar and sonar. The sample rate requirements of these applications range from 10 KHz to 100 MHz. Real time implementation of these systems requires design of hardware which can process signal samples as these are received from the source, as opposed to storing them in buffers and processing them in batch mode. Efficient implementation of real time hardware for DSP applications requires study of families of architectures and implementation styles out of which an appropriate architecture can be selected for a specified application. To this end, the digit-serial implementation style is proposed as an appropriate design methodology for cases where bit-serial systems cannot meet the sample rate requirements, and bit-parallel systems require excessive hardware. The number of bits processed in a clock cycle is referred to as the digit-size. The hardware complexity and the achievable sample rate increase with increase in the digit-size. As special cases, a digit serial system is reduced to bit-serial or bit-parallel when the digit-size is selected to equal one or the word-length, respectively. A family of implementations can be obtained by changing the digit-size parameter, thus permitting an optimal trade-off between throughput and size. Because of their structured architecture, digit-serial designs lend themselves to automatic compilation from algorithmic descriptions. An implementation of this design methodology, the Parsifal silicon compiler was developed at the General Electric Corporate Research and Development laboratory."

The book has a dual purpose. The first is to expose a general methodology to solve problems of electromagnetism in geometries constituted of angular regions. The second is to bring the solutions of some canonical problems of fundamental importance in modern electromagnetic engineering with the use of the Wiener-Hopf technique. In particular, the general mathematical methodology is very ingenious and original. It is based on sophisticated and attractive procedures exploiting simple and advanced properties of analytical functions. Once the reader has acquired the methodology, she/he can easily obtain the solution of the canonical problems reported in the book. The book can be appealing also to readers who are not directly interested in the detailed mathematical methodology and/ or in electromagnetics. In fact the same methodology can be extended to acoustics and elasticity problems. Moreover, the proposed practical problems with their solutions constitute a list of reference solutions and can be of interests in engineering production in the field of radio propagations, electromagnetic compatibility and radar technologies.

This book originated from a workshop held at the DATE 2005 conference, namely Designing Complex SOCs. It is a state-of-the-art in issues related to System-on-Chip (SoC) design by leading experts in the fields, and covers IP development, verification, integration, chip implementation, testing and software. SOC design is fast becoming the key area of focus that engineers and researchers from the Electronic Design Automation field are focussing on in their quest to further develop Integrated Circuit technology. The more systems and even networks that we can integrate on one piece of silicon, the faster, cheaper, more powerful and efficient the technology will become. Essential Issues in SOC Design contains valuable academic and industrial examples for those involved with the design of complex SOCs, all contributors are selected from a region of the world that is generally known to lead the SOC-Revolution, namely Asia.

The application of computational electromagnetics to real-world EMI/EMC engineering is an emerging technology. With the advancement in electronics, EMI/EMC issues have greatly increased in complexity. As a result, it is no longer possible to rely exclusively on traditional techniques and expect cost-effective solutions. The first edition of this book introduced computational electromagnetics to EMI/EMC engineering. This second edition continues the introduction of computational electromagnetics to EMI/EMC engineering, but also adds new modeling techniques, namely the Partial Element Equivalent Circuit method and the Transmission Line Matrix method, and updates to the science of EMI/EMC modeling that have occurred since the first edition was published. This book combines the essential elements of electromagnetic theory, computational techniques, and EMI/EMC engineering as they apply to computational modeling for EMI/EMC applications. It is intended to provide an understanding for those interested in incorporating modeling techniques in their work. A variety of modeling techniques are needed for anyone interested in using computational modeling in the real world. This book includes an introduction of all the popular modeling techniques, such as the Finite-Difference Time-Domain method, the Method of Moments, the Finite Element Method, the Partial Element Equivalent Circuit method and the Transmission Line Matrix method. EMI/EMC Computational Modeling Handbook, Second Edition will serve many different levels of readers. It will serve as a basic introduction to modeling as applied to EMI/EMC problems for the engineer interested in getting started, and it will help the person already using modeling as a tool to become more effective in using different modeling techniques. It will also be useful for the engineer who is familiar with computational techniques and wishes to apply them to EMI/EMC applications. This book can also be used as a text to help students of electromagnetic theory and application better understand real-world challenges facing engineers.