Wireless metropolitan area networks (WirelessMANs) is emerging as a promising broadband wireless access (BWA) technology to provide high-speed, high bandwidth efficiency and high-capacity multimedia services for residential as well as enterprise applications. It is observed that wirelessMAN (e.g., WiMAX) is even regarded as a 4G technology. For the success of the wirelessMANs, international standardization organiza- tions are very actively specifying the standards IEEE 802.16, ETSI HiperMAN and Korea WiBro.
标签： BroadbanMobile WiMAX Toward Broadband wirelessd Wireless Mobile Toward WiMAX
上传时间： 2020-05-30
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Mobile and wireless application development has come a long way in the past few years. It has progressed beyond the hype of wireless Web applications for consumers to the reality of high-value mobile applications for corporate users. Opportunities abound for creating new mobile and wireless applications that provide vital benefits to any business. A sampling of these benefits includes increased worker productivity, reduced processing costs, heightened accuracy, and competitive advantage. In contrast is the concern that developing mobile and wireless applications will involve many new technologies and concepts that many corporate developers are still learning to use.
标签： Essentials Wireless Mobile Design and
上传时间： 2020-05-30
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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
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Advances in communication and networking technologies are rapidly making ubiq- uitous network connectivity a reality. wireless networks are indispensable for supporting such access anywhere and at any time. Among various types of wire- less networks, multihop wireless networks (MWNs) have been attracting increasing attention for decades due to its broad civilian and military applications. Basically, a MWN is a network of nodes connected by wireless communication links. Due to the limited transmission range of the radio, many pairs of nodes in MWNs may not be able to communicate directly, hence they need other intermediate nodes to forward packets for them. Routing in such networks is an important issue and it poses great challenges.
标签： Multihop Wireless Networks
上传时间： 2020-05-31
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Wireless communication is witnessing tremendous growth with great proliferation of different standards covering wide ,local and personal area networks
标签： Multi-Standard Receivers Wireless CMOS
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In the past few decades, a technological revolution has occurred that has changed the way we live in dramatic ways. This technological revolution is the result of the emergence and evolution of a wide variety of new wireless networking tech- nologies. Now people using these technologies are able to access the network and control many applications at will with their handheld devices anywhere, anytime. Although these technologies have made a long lasting impact in the revolution, it has also opened up various challenging issues which are yet to be resolved to make them more efficient and cost-effective.
标签： Next-Generation Technologies Wireless
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Before delving into the details of orthogonal frequency division multiplexing (OFDM), relevant background material must be presented first. The purpose of this chapter is to provide the necessary building blocks for the development of OFDM principles. Included in this chapter are reviews of stochastic and random process, discrete-time signals and systems, and the Discrete Fourier Transform (DFT). Tooled with the necessary mathematical foundation, we proceed with an overview of digital communication systems and OFDM communication systems. We conclude the chapter with summaries of the OFDM wireless LAN standards currently in existence and a high-level comparison of single carrier systems versus OFDM.
上传时间： 2020-05-31
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Emerging technologies such as WiFi and WiMAX are profoundly changing the landscape of wireless broadband. As we evolve into future generation wireless networks, a primary challenge is the support of high data rate, integrated multi- media type traffic over a unified platform. Due to its inherent advantages in high-speed communication, orthogonal frequency division multiplexing (OFDM) has become the modem of choice for a number of high profile wireless systems (e.g., DVB-T, WiFi, WiMAX, Ultra-wideband).
标签： OFDM-Based Broadband Networks Wireless
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Optical wireless communication is an emerging and dynamic research and development area that has generated a vast number of interesting solutions to very complicated communication challenges. For example, high data rate, high capacity and minimum interference links for short-range communication for inter-building communication, computer-to-computer communication, or sensor networks. At the opposite extreme is a long-range link in the order of millions of kilometers in the new mission to Mars and other solar system planets.
标签： Communication Wireless Optical Systems
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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
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