With the rapid growth of the wireless mobile applications, wireless voice has begun to challenge wireline voice, whereas the desire to access e-mail, surf the Web or download music (e.g., MP3) wirelessly is increasing for wireless data. While second generation (2G) cellular wireless systems, such as cdmaOne1, GSM2 and TDMA3, introduced digital technology to wireless cellular systems to deal with the increasing demand for wireless applications, there is still the need for more spectrally efficient technologies for two reasons. First, wireless voice capacity is expected to continue to grow. Second, the introduction of high-speed wireless data will require more bandwidth.
标签： Wireless Systems Mobile Beyond and 3G
上传时间： 2020-05-30
上传用户：shancjb
Do you have a mobile phone? We think you probably do, one way or another. We would also guess that you might use it for many diff erent things in the course of your everyday life—as a telephone certainly, but also as an address book, as a clock or watch, as a camera, or now as a connection to your computer, email and the internet. Th ere will be a range of people you use it to contact (or not), and various strategies you use to take calls—or send texts, or take photos, or receive emails, or search online (or not, in diff erent situations). Th ere are also likely to be a range of social relation- ships in your life that your mobile phone helps to maintain—or disrupts, or inter- venes in, or makes possible, or complicates, or just plain helps to handle.
标签： Communications Introduction Mobile Media New An to
上传时间： 2020-05-30
上传用户：shancjb
Rapid growth of wireless communication services in recent decades has created a huge demand of radio spectrum. Spectrum scarcity and utilization inefficiency limit the development of wireless networks. Cognitive radio is a promising tech- nology that allows secondary users to reuse the underutilized licensed spectrum of primary users. The major challenge for spectrum sharing is to achieve high spectrum efficiency while making non-intrusive access to the licensed bands. This requires in- formation of availability and quality of channel resources at secondary transmitters, however, is difficult to be obtained perfectly in practice.
标签： Opportunistic Spectrum Sharing
上传时间： 2020-05-31
上传用户：shancjb
The ever-increasing demand for private and sensitive data transmission over wireless net- works has made security a crucial concern in the current and future large-scale, dynamic, and heterogeneous wireless communication systems. To address this challenge, computer scientists and engineers have tried hard to continuously come up with improved crypto- graphic algorithms. But typically we do not need to wait too long to find an efficient way to crack these algorithms. With the rapid progress of computational devices, the current cryptographic methods are already becoming more unreliable. In recent years, wireless re- searchers have sought a new security paradigm termed physical layer security. Unlike the traditional cryptographic approach which ignores the effect of the wireless medium, physi- cal layer security exploits the important characteristics of wireless channel, such as fading, interference, and noise, for improving the communication security against eavesdropping attacks. This new security paradigm is expected to complement and significantly increase the overall communication security of future wireless networks.
标签： Communications Physical Security Wireless Layer in
上传时间： 2020-05-31
上传用户：shancjb
This book stems from its ancestor Digital Transmission Theory,published by Prentice-Hall in 1987 and now out of print. Following the suggestion of several colleagues who complained about the unavailability of a textbook they liked and adopted in their courses, laying a strong emphasis on wireless communication. We hope that those who liked the previous book will find again its flavor here,while new reader, untouched by nostalgia, will judge it favorably.
标签： Transmission Principles Digital of
上传时间： 2020-05-31
上传用户：shancjb
Radio propagation measurements and channel modelling continue to be of fundamental importance to radio system design. As new technology enables dynamic spectrum access and higher data rates, radio propagation effects such as shadowing, the presence of multipath and frequency dispersion are the limiting factors in the design of wireless communication systems. While there are several books covering the topic of radio propagation in various frequency bands, there appears to be no books on radio propagation measurements, which this book addresses at length.
标签： Propagation Measurement Radio
上传时间： 2020-06-01
上传用户：shancjb
Digital mobile wireless communication and the Internet have undergone a fantastic growth in the last few years and, despite originating from two different worlds, they are converging. This convergence corresponds to the evolution of mobile systems towards the highest broadband data transmissions (GSM, EDGE/GPRS, UMTS then HSDPA), while the computing world gets equipped with wireless technologies such as Wi-Fi or Wi-Max.
标签： Reconfigurable Systems Mobile Radio
上传时间： 2020-06-01
上传用户：shancjb
The fi rst edition of this book came about because Regina Lundgren had always been fascinated with communication. She started writing novels in the third grade. When she was asked on her fi rst day at the University of Washington what she hoped to do with her degree in scientifi c and technical communication, she replied, “I want to write environ- mental impact statements.” When Patricia Clark hired her to work at the Pacifi c Northwest National Laboratory to do just that, she was overjoyed.
标签： COMMUNICATION RISK
上传时间： 2020-06-01
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The following sections profile many of the vendors in the NFV market. The individual profiles were created through a collaborative effort between SDNCentral’s Research Team and the Vendor’s product experts. SDNCentral worked under the assumption the information provided by the vendors was factual, auditing the submissions only to remove unverifiable claims and hyperbole. Extended profiles can be viewed online. While every attempt has been made to validate the capabilities listed in the profiles, SDNCentral advises end users to verify the veracity of each claim for themselves in their actual deployment environments. SDNCentral cannot be held liable for unexpected operations, damages or incorrect operation due to any inaccuracies listed here. SDNCentral welcomes feedback and additional information from end users based on their real-world experiences with the products and technologies listed. The SDNCentral research team can be reached at
标签： SDxCentral-Mega-NFV-Report
上传时间： 2020-06-01
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Convergence between the two largest networks (Telecom and IP) is taking place very rapidly and at diff erent levels: (1) network level: unifi cation of IP networks with traditional Telecom networks through evolving standards (Session Initiation Protocol (SIP), Realtime Transfer Protocol (RTP), SS7, 3G) to support interopera- bility; (2) service level: traditional Telecom services like voice calls are being provi- sioned on the IP backbone (VoIP), while traditional IP services (most data-driven services such as multimedia, browsing, chatting, gaming, etc.) are accessible over the Telecom network.
标签： Platforms Delivery Service
上传时间： 2020-06-01
上传用户：shancjb
