Communication has been one of the deepest needs of the human race throughout recorded history. It is essential to forming social unions, to educating the young, and to expressing a myriad of emotions and needs. Good communication is central to a civilized society. The various communication disciplines in engineering have the purpose of providing technological aids to human communication. One could view the smoke signals and drum rolls of primitive societies as being technological aids to communication, but communication technology as we view it today became important with telegraphy, then telephony, then video, then computer communication, and today the amazing mixture of all of these in inexpensive, small portable devices.
標簽： communication Principles digital of
上傳時間： 2020-05-31
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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
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Commoditization is a serious threat to the telecommunications industry. Most CSPs offer similar services at rates designed to win what has become a price war. As a result, many face decreasing margins and difficulty sustaining differentiation based on prices or products alone. On top of commoditization, CSPs also face competition from OTT providers and an increasingly knowledgeable and demanding customer base. With access to growing amounts of data from an ever-increasing number of sources and devices, today’s empowered, savvy consumers know what they want and expect to get it.
標簽： RestoringConnections_IBM_CPL
上傳時間： 2020-06-01
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The use of mobile devices now surpasses that of traditional computers: wireless users will hence soon be demanding the same rich multimedia services on their mobile devices that they have on their desktop personal computers. In addition, new services will be added, especially related with their mobile needs, such as location-based information services.
標簽： Communications Technology Wireless Trends in
上傳時間： 2020-06-01
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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.
標簽： Telecommunications Management Equipment Thermal of
上傳時間： 2020-06-01
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Recent advances in wireless communication technologies have had a transforma- tive impact on society and have directly contributed to several economic and social aspects of daily life. Increasingly, the untethered exchange of information between devices is becoming a prime requirement for further progress, which is placing an ever greater demand on wireless bandwidth. The ultra wideband (UWB) system marks a major milestone in this progress. Since 2002, when the FCC allowed the unlicensed use of low-power, UWB radio signals in the 3.1–10.6GHz frequency band, there has been significant synergistic advance in this technology at the cir- cuits, architectural and communication systems levels. This technology allows for devices to communicate wirelessly, while coexisting with other users by ensuring that its power density is sufficiently low so that it is perceived as noise to other users.
上傳時間： 2020-06-01
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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.
標簽： Multi-hop Networks WiMAX WiFi Mesh LTE and
上傳時間： 2020-06-01
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Wireless networking is undergoing a transformation from what has been primarily a medium for supporting voice traffic between telephones, into what is increasingly becoming a medium for supporting traffic among a variety of digital devices transmitting media of many types (voice, data, images, video. etc.) Wireline networking underwent a similar transformation in the 1990s, which led to an enormous build-up in the capacity of such networks, primarily through the addition of new optical fiber, switches and other infrastructure.
標簽： Multiusers Detection Wireless Networks
上傳時間： 2020-06-01
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The advent of modern wireless devices, such as smart phones and MID 1 terminals, has revolutionized the way people think of personal connectivity. Such devices encompass multiple applications ranging from voice and video to high-speed data transfer via wireless networks. The voracious appetite of twenty-first century users for supporting more wireless applications on a single device is ever increasing. These devices employ multiple radios and modems that cover multiple frequency bands and multiple standards with a manifold of wireless applications often running simultaneously.
標簽： Architectures Wireless Receiver Design and
上傳時間： 2020-06-01
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A wireless ad-hoc network is a wireless network deployed without any infrastructure. In such a network, there is no access point or wireless router to forward messages among the computing devices. Instead, these devices depend on the ad-hoc mode of their wireless net‐ work interface cards to communicate with each other. If the nodes are within the transmis‐ sion range of the wireless signal, they can send messages to each other directly. Otherwise, the nodes in between will forward the messages for them. Thus, each node is both an end system and a router simultaneously.
上傳時間： 2020-06-01
上傳用戶：shancjb
