This book addresses two aspects of network operation quality; namely, resource management and fault management. Network operation quality is among the functions to be fulfilled in order to offer quality of service, QoS, to the end user. It is characterized by four parameters: – packet loss; – delay; – jitter, or the variation of delay over time; – availability. Resource management employs mechanisms that enable the first three parameters to be guaranteed or optimized. Fault management aims to ensure continuity of service.
標(biāo)簽： Ethernet Networks MPLS and IP
上傳時間： 2020-05-27
上傳用戶：shancjb
To meet the future demand for huge traffic volume of wireless data service, the research on the fifth generation (5G) mobile communication systems has been undertaken in recent years. It is expected that the spectral and energy efficiencies in 5G mobile communication systems should be ten-fold higher than the ones in the fourth generation (4G) mobile communication systems. Therefore, it is important to further exploit the potential of spatial multiplexing of multiple antennas. In the last twenty years, multiple-input multiple-output (MIMO) antenna techniques have been considered as the key techniques to increase the capacity of wireless communication systems. When a large-scale antenna array (which is also called massive MIMO) is equipped in a base-station, or a large number of distributed antennas (which is also called large-scale distributed MIMO) are deployed, the spectral and energy efficiencies can be further improved by using spatial domain multiple access. This paper provides an overview of massive MIMO and large-scale distributed MIMO systems, including spectral efficiency analysis, channel state information (CSI) acquisition, wireless transmission technology, and resource allocation.
標(biāo)簽： Large-scale Antenna Systems
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(biāo)簽： Self-Organising Networks LTE
上傳時間： 2020-05-27
上傳用戶：shancjb
The growth of mobile technologies is remarkable. At a recent Mobile World Congress Conference, Eric Schmidt, CEO of Google predicted that within three years, smart phones will surpass Personal Com- puter sales. The number of mobile phones used worldwide has exceeded 4.6 billion with continued growth expected in the future. In fact, in the United States alone, the numbers of mobile phone users comprise over 80% of the population.
標(biāo)簽： Opportunities Consumption Technology Mobile
上傳時間： 2020-05-30
上傳用戶：shancjb
In general there are three different techniques for performance evaluation of systems and networks: mathematical analysis, measurements, and computer simulation. All these techniques have their strength and weaknesses. In the literature there are plenty of discussions about when to use which technique, how to apply it, and which pitfalls are related to which evaluation technique.
標(biāo)簽： Simulation Modeling Network Tools and for
上傳時間： 2020-05-31
上傳用戶：shancjb
Theartofcomputationofelectromagnetic(EM)problemshasgrownexponentially for three decades due to the availability of powerful computer resources. In spite of this, the EM community has suffered without a suitable text on the computational techniques commonly used in solving EM-related problems. Although there have been monographs on one particular technique or another, the monographs are written for the experts rather than students. Only a few texts cover the major techniques and dothatinamannersuitableforclassroomuse.Itseemsexpertsinthisareaarefamiliar with one or a few techniques but not many seem to be familiar with all the common techniques. This text attempts to fill that gap.
標(biāo)簽： Electromagnetics Techniques Numerical in
上傳時間： 2020-05-31
上傳用戶：shancjb
The focus of this book is on developing computational algorithms for transmit wave- form design in active sensing applications, such as radar, sonar, communications and medical imaging. Waveforms are designed to achieve certain desired properties, which are divided into three categories corresponding to the three main parts in the book, namely good aperiodic correlations, good periodic correlations and beampattern match- ing.
上傳時間： 2020-06-01
上傳用戶：shancjb
During the past three decades, the world has seen signifi cant changes in the telecom- munications industry. There has been rapid growth in wireless communications, as seen by large expansion in mobile systems. Wireless communications have moved from fi rst-generation (1G) systems primarily focused on voice communications to third-generation (3G) systems dealing with Internet connectivity and multi-media applications. The fourth-generation (4G) systems will be designed to connect wire- less personal area networks (WPANs), wireless local area networks (WLANs) and wireless wide-area networks (WWANs).
標(biāo)簽： Communications Networking Wireless
上傳時間： 2020-06-01
上傳用戶：shancjb
Wirelesscommunications,especiallyinitsmobileform,hasbroughtusthefreedomofmobility andhaschangedthelifestylesofmodernpeople.Waitingatafixedlocationtoreceiveormakea phone call, or sitting in front of a personal computer to send an e-mail or download a video program, has become an old story. Nowadays it is commonplace for people to talk over a cell phonewhilewalkingonthestreet,ortodownloadandwatchamoviewhiletravelingonatrain. Thisisthebenefitmadeavailabletousbythesuccessfulevolutionofwirelesscommunications over three generations, with the fourth generation being under way.
標(biāo)簽： Communications Management Wireless Resource
上傳時間： 2020-06-01
上傳用戶：shancjb
For more than three decades, Micro Electro Mechanical Systems (MEMS) have steadily transitioned out of research labs and into production forming a more than $10 billion market [1]. MEMS devices such as accelerometers, pressure sensors and microphones, to name a few, have seen immense utilization, particularly in the consumer electronics market, because of their compact sizes and minute power consumptions. In addition, these devices benefit from batch fabrication, which has enabled year-over-year reductions in cost [2]. In recent years,
標(biāo)簽： Frequency Tunable MEMS
上傳時間： 2020-06-06
上傳用戶：shancjb
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