Over the past ten years there has been a revolution in the devel- opment and acceptance of mobile products. In that period, cel- lular telephony and consumer electronics have moved from the realm of science fiction to everyday reality. Much of that revolu- tion is unremarkable – we use wireless, in its broadest sense, for TV remote controls, car keyfobs, travel tickets and credit card transactions every day.
标签： Short-Range Wireless
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In Helsinki during a visiting lecture, an internationally well-known professor in communica- tionssaid,‘Inthecommunicationssocietywehavemanagedtoconvertourproposalsandideas to real products, not like in the control engineering society. They have very nice papers and strong mathematics but most of the real systems still use the old PID controllers!’. As our background is mainly in control as well as communications engineering, we know that this thought is not very accurate. We agree that most of the practical controllers are analog and digital PID controllers, simply because they are very reliable and able to achieve the required control goals successfully. Most of the controllers can be explained in terms of PID. The reasons behind this impressive performance of PID will be explained in Chapter 2.
标签： Communications Engineering Wireless Systems in
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The first practical examples of mobile communications were used in many countries like the USA, the UK and Germany in military services, and played a significant role in the First World War to transfer important information from the front to headquarters to take further actions. Good and secure wireless communications were an important need for all military services – army, navy and air force. In this respect, the Second World War was a big experimental battlefield for the development and evolution of mobile radio. It was in the interests of governments that after the Second World War the military investment should be paid back by civilian use, and all western European countries started their so-called first generation of mobile communication networks.
标签： Multimedia Business Mobile The
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Wireless communication has become increasingly important not only for professional appli- cations but also for many fields in our daily routine and in consumer electronics. In 1990, a mobile telephone was still quite expensive, whereas today most teenagers have one, and they use it not only for calls but also for data transmission. More and more computers use wireless local area networks (WLANs), and audio and television broadcasting has become digital.
标签： Applications and Theory OFDM CDMA of
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The need to develop reliable microelectronic devices capable of operating at high speeds with complex functionality requires a better understanding of the factors that govern the thermal performance of electronics. With an increased demand on system reliability and performance combined with miniaturization of the devices, thermal consideration has become a crucial factor in the design of elec- tronic packages, from chip to system levels.
标签： Telecommunications Management Equipment Thermal of
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T his book covers basic communications theory and practical imple- mentation of transmitters and receivers. In so doing, I focus on dig- ital modulation, demodulation methods, probabilities, detection of digital signals, and spread spectrum system design and analysis. This book was written for those who want a good understanding of the basic prin- ciples of digital wireless communication systems, including spread spec- trum techniques. This book also provides a good intuitive and practical approach to digital communications. Therefore it is a valuable resource for anyoneinvolvedinwirelesscommunicationsandtransceiverdesignfordig- ital communications. The reader will gain a broad understanding of basic communication principles for transceiver design, digital communications, and spread spectrum, along with examples of many types of commercial and military data link systems.
标签： Transceiver System Design
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Having dealt with in-depth analysis of SS#7, GSM and GPRS networks I started to monitor UTRAN interfaces approximately four years ago. Monitoring interfaces means decoding the data captured on the links and analysing how the different data segments and messages are related to each other. In general I wanted to trace all messages belonging to a single call to prove if the network elements and protocol entities involved worked fine or if there had been failures or if any kind of suspicious events had influenced the normal call proceeding or the call’s quality of service. Cases showing normal network behaviour have been documented in Kreher and Ruedebusch (UMTS Signaling. John Wiley & Sons, Ltd, 2005), which provides examples for technical experts investigating call flows and network procedures.
标签： Performance Measurement Practical Guide UMTS
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Two of the major developments reshaping the telecommunications landscape are mobile wireless connectivity and the migration of voice telephone services to IP technology. Those two ideas come together in networks that carry voice services over a wireless LAN (VoWLAN). The purpose of this text is to provide network professionals with the technical background and practical guidance needed to deploy these networks successfully.
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n the first part of this book, we give an introduction to the basic applications of wireless com- munications, as well as the technical problems inherent in this communication paradigm. After a brief history of wireless, Chapter 1 describes the different types of wireless services, and works out their fundamental differences. The subsequent Section 1.3 looks at the same problem from a different angle: what data rates, ranges, etc., occur in practical systems, and especially, what combination of performance measures are demanded (e.g., what data rates need to be transmitted over short distances; what data rates are required over long distances?) Chapter 2 then describes the technical challenges of communicating without wires, putting special emphasis on fading and co-channel interference. Chapter 3 describes the most elementary problem of designing a wireless system, namely to set up a link budget in either a noise-limited or an interference-limited system. After studying this part of the book, the reader should have an overview of different types of wireless services, and understand the technical challenges involved in each of them. The solutions to those challenges are described in the later parts of this book.
标签： Communications Wireless Edition 2nd
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The use of optical free-space emissions to provide indoor wireless commu- nications has been studied extensively since the pioneering work of Gfeller and Bapst in 1979 [1]. These studies have been invariably interdisciplinary in- volving such far flung areas such as optics design‚ indoor propagation studies‚ electronics design‚ communications systems design among others. The focus of this text is on the design of communications systems for indoor wireless optical channels. Signalling techniques developed for wired fibre optic net- works are seldom efficient since they do not consider the bandwidth restricted nature of the wireless optical channel.
标签： Communication Wireless Optical Systems
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