One of the prerequisites for the development of telecommunication services is the UNDERSTANDING of the propagation of the waves, either acoustic, electromagnetic, radio or light waves, which are used for the transmission of information. In this work, we shall limit ourselves to the study of radio waves: this term apply to the electromagnetic waves used in radio communications. Their frequency spectrum is very broad, and is divided into the following frequency bands : ELF waves (f < 3 kHz), VLF (3-30 kHz), LF waves (30-300 kHz), MF waves (300-3000 kHz), HF (3-30 MHz), VHF waves (30-300 MHz), UHF waves (300-3000 MHz), SHF waves (3-30 GHz), EHF waves (30-300 GHz) and sub- EHF waves (300-3000 GHz).
标签： Propagation Radio Wave
上传时间： 2020-06-01
上传用户：shancjb
An UNDERSTANDING of the policies, regulations, standards and techniques of radio spectrum management is useful to those who manage and administrate it, to operators, to equipment providers and to the users of wireless communication (i.e., all of us). For many years the author has been deeply involved in ruling the RF spectrum at the national, regional and global levels. The book is based on the professional experience of the author, his academic courses, presenta- tions and tutorials in five continents. The book reflects this legacy and will be of use to engineers, lawyers and economists, who serve the global industry of the wireless world; in it they may find solutions to the problems they frequently encounter.
标签： Management Spectrum Radio
上传时间： 2020-06-01
上传用户：shancjb
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
上传时间： 2020-06-01
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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
上传时间： 2020-06-01
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In the two years since this book was first published, ultra wideband (UWB) has advanced and consolidated as a technology, and many more people are aware of the possibilities for this exciting technology. We too have expanded and consolidated materials in this second edition in the hope that ‘Ultra Wideband: Signals and Systems in Communication Engineering’ will continue to prove a useful tool for many students and engineers to come to an UNDERSTANDING of the basic technologies for UWB.
标签： Wideband Signals Systems Ultra and
上传时间： 2020-06-01
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As I have increasingly moved away from the world of research and into thatofmanagementandbusiness,ithasbecomeapparenttomethatthere are many people from a nontechnical background who need to under- standcellularsystemsinmoredetailinordertobeabletoperformtheir job,beitanalyzingfinancialinvestments,runningcallcenters,ormarket- ing cellular services.
标签： UNDERSTANDING Cellular Radio
上传时间： 2020-06-01
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The use of light to send messages is not new. Fires were used for signaling in biblical times, smoke signals have been used for thousands of years and flashing lights have been used to communicate between warships at sea since the days of Lord Nelson. The idea of using glass fibre to carry an optical communications signal originated with Alexander Graham Bell. However this idea had to wait some 80 years for better glasses and low-cost electronics for it to become useful in practical situations.
标签： Communications UNDERSTANDING Optical
上传时间： 2020-06-01
上传用户：shancjb
The dictionary definition of telecommunications is ‘communication over long distance by cable, telegraph, telephone or broadcasting’, but since its initiation over 100yearsagothingshavemovedrapidly.Telecommunicationsisnowaverycomplex industrywithmanydifferentpressures,operatinginahighlydynamic environment.It is best viewed as part of a wider industry known as information and communication technology (ICT). The purpose of this chapter is to explain where telecommunication fits in, to highlight some of the complexities – hopefully to simplify them – and to position the industry in today’s dynamic business environment.
标签： Telecommunications UNDERSTANDING Business
上传时间： 2020-06-01
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Telecommunications is today widely understood to mean the electrical means of communicating over a distance. The first form of telecommunications was that of the Telegraph, which was invented quite independently in 1837 by two scientists, Wheatstone and Morse. Telegraphy was on a point-to-point unidirectional basis and relied on trained operators to interpret between the spoken or written word and the special signals sent over the telegraph wire. However, the use of telegraphy did greatly enhance the operations of railways and, of course, the dissemination of news and personal messages between towns.
标签： Telecommunications UNDERSTANDING Networks
上传时间： 2020-06-01
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Electrostatic discharge (ESD) phenomena have been known to mankind since the Greek Empire when Thales of Miletus, one of the Seven Sages of Greece, noticed the attraction of strands of hay to amber, leading to the coining of the word ‘‘electron.’’ In the 17th century, Gilbert and Cabeo addressed the attractive and repulsive nature of electricity. In the 18th century, a rapid increase of interest occurred for scientists in the UNDERSTANDING of electrical physics—Gray, du Fay, Nollet, Musschenbroeck, Franklin, Watson, Aepinus, Canton,
上传时间： 2020-06-05
上传用户：shancjb
