For nearly a hundred years telecommunications provided mainly voice services and very low speed data (telegraph and telex). With the advent of the Internet, several data services became mainstream in telecommunications; to the point that voice is becoming an accessory to IP-centric data networks. Today, high-speed data services are already part of our daily lives at work and at home (web surfing, e-mail, virtual private networks, VoIP, virtual meetings, chats...). The demand for high-speed data services will grow even more with the increasing number of people telecommuting.
上傳時間: 2020-05-27
上傳用戶:shancjb
Mobilenetworkoperatorswillmeetmanychallengesinthecomingyears.Itisexpectedthatthe numberofpeopleconnected,wirelineandwireless,willreachfivebillionby2015.Atthesame time, people use more wireless services and they expect similar user experience to what they can now get from fixed networks. Because of that we will see a hundred-fold increase in network traffic in the near future. At the same time markets are saturating and the revenue per bit is dropping.
標簽: Self-Organising Networks LTE
上傳時間: 2020-05-27
上傳用戶:shancjb
Nature is seldom kind. One of the most appealing uses for radio- telephone systems—communication with people on the move—must over- come radio transmission problems so difficult they challenge the imagina- tion. A microwave radio signal transmitted between a fixed base station and a moving vehicle in a typical urban environment exhibits extreme variations in both amplitude and apparent frequency.
標簽: Communications Microwave Mobile
上傳時間: 2020-05-28
上傳用戶:shancjb
By definition, the term “mobile-radio communications” describes any radio communication link between two terminals of which one or both are in motion or halted at unspecified locations and of which one may actually be a fixed terminal such as a base station. This definition applies to both mobile-to-mobile and mobile-to-fixed radio communica- tion links. The mobile-to-mobile link could in fact consist of a mobile- to-fixed-to-mobile radio communication link.The term “mobile” applies to land vehicles, ships at sea, aircraft, and communications satellites. In tactical situations, mobile-radio systems may include any or all of these types of mobile terminals.
標簽: Communications Engineering Mobile
上傳時間: 2020-05-30
上傳用戶:shancjb
Notwithstanding its infancy, wireless mesh networking (WMN) is a hot and growing field. Wireless mesh networks began in the military, but have since become of great interest for commercial use in the last decade, both in local area networks and metropolitan area networks. The attractiveness of mesh networks comes from their ability to interconnect either mobile or fixed devices with radio interfaces, to share information dynamically, or simply to extend range through multi-hopping.
上傳時間: 2020-05-31
上傳用戶:shancjb
European Research Framework programs are public policy instruments designed to strengthen European competitiveness through cooperation. Although they have a fixed time frame, determined research themes, and a specific expected impact, the achievements in research and development (R&D) made by these funded proj- ects pave the way for a research continuum.
標簽: Communications Horizons Wireless Mobile New and in
上傳時間: 2020-05-31
上傳用戶:shancjb
European Research Framework Programs are a public policy instrument to strengthen European competitiveness through cooperation. Although they have a fixed timeframe, determined research themes, and specific expected impact, the achievements in research and development (R&D) made by the funded projects pave the way for a research continuum.
標簽: New Horizons Mobile Wireless
上傳時間: 2020-05-31
上傳用戶:shancjb
This book is a result of the recent rapid advances in two related technologies: com- munications and computers. Over the past few decades, communication systems have increased in complexity to the point where system design and performance analysis can no longer be conducted without a significant level of computer sup- port. Many of the communication systems of fifty years ago were either power or noise limited. A significant degrading effect in many of these systems was thermal noise, which was modeled using the additive Gaussian noise channel.
標簽: Communication Principles Simulation Systems of
上傳時間: 2020-05-31
上傳用戶:shancjb
Wireless means different things to different people. For this book, it refers to the radio systems that provide point-to-point, point-to-multipoint, and Earth-space communications over transmission links that propagate outside buildings through the lower atmosphere. Wireless systems are being built that provide data transmission between computers and other devices on one’s own desk. These are part of the wireless world but not the part where, except for interference perhaps, the atmosphere has any influence. The intent of this book is to provide a description of the physical phenomena that can affect propagation through the atmosphere, present sample measurements and statistics, and provide models that system designers can use to calculate their link budgets and estimate the limitations the atmosphere may place on their design.
標簽: Communication Propagation Handbook Wireless for
上傳時間: 2020-05-31
上傳用戶:shancjb
Quality of Service ( QoS ) has always been in a world of its own, but as the technology has been refi ned and has evolved in recent years, QOS usage has increased to the point where it is now considered a necessary part of network design and operation. As with most technologies, large - scale deployments have led to the technology becoming more mature, and QOS is no exception.
標簽: QOS-Enabled Networks
上傳時間: 2020-05-31
上傳用戶:shancjb