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 دانلود کتاب مرجع شبکه های کامپیوتری تننبام
مرجع کنکور کارشناسی ارشد رشته های فناوری اطلاعات . کامپیوتر
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 Next-generation broadband wireless standards, e.g. IEEE 802.16e and Third Generation Partnership Project – Long Term Evolution (3GPP-LTE), use Orthogonal Frequency Division Multiple Access (OFDMA) as the preferred physical layer multiple access scheme, esp. for the downlink. Due to the limited resources available at the base station, e.g. bandwidth and power, intelligent allocation of these resources to the users is crucial for delivering the best possible quality of service (QoS) to the consumer with the least cost |
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 Wireless mesh network (WMN) is a radical network form of the everevolving wireless networks that marks the divergence from the traditional centralized wireless systems such as cellular networks and wireless local area networks (LANs). Similar to the paradigm shift, experienced in wired networks during the late 1960s and early 1970s that led to a hugely successful and distributed wired network form— the Internet—WMNs are promising directions in the future of wireless networks. The primary advantages of a WMN lie in its inherent fault tolerance against network failures, simplicity of setting up a
network, and the broadband capabilit
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 Recent emergence of affordable, portable wireless communication and computation devices and concomitant advances in the communication infrastructure have resulted in the rapid growth of mobile wireless networks. On one hand, this has led to the exponential growth of the cellular network, which is based on the combination of wired and wireless technologies. Nowadays, the number of cellular network users is approaching two billion worldwide (expected at end 2005). Although the research and development efforts devoted to traditional wireless networks are still considerable, the interest of the scientific and industrial community in the realm of telecommunications has recently shifted to more challenging scenarios in which a group of mobile units equipped with radio transceivers communicate without any fixed infrastructure
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 The Internet, an upstart academic experiment in the late 1960s, struggles with identity and success today. From the ARPANET to the NSFnet to ANYBODYSNET, the Internet is no longer owned by a single entity; it is owned by anybody who can afford to buy space on it. Tens of millions of users are seeking connectivity, and tens of thousands of companies are feeling left out if they do not tap into the Internet |
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 The first microprocessors appeared in the early 1970s and were immediately employed in personal computers. A popular question in those early years was: Why would anyone want a computer at home? Typical answers were: To balance your checking account, to store your recipes, and to help you compute your taxes. It was only a few years later, when many already owned personal computers, that computer owners discovered the real reasons for the usefulness of their machines. We buy and use personal computers mainly because they provide us with communications and entertainment
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