A high bit rate flexible MAC protocol for monitoring applications using 60ghz radio technology

In recent years there has been a growing trend in optical wireless convergence. One particular aspect of this is 60 GHz radio-over-fiber technology. It is intended for use in wireless personal area networks. However, we think that the same technology could be used for monitoring applications in the indoor environment. It could be used to detect emergency situations or to detect intruders. We shall examine reasons why this choice might be a suitable one. We shall then propose a MAC layer protocol to accomplish this task. Since in case of emergency we might require to obtain data from only one node for an extended duration, flexibility in implementation is required. We shall develop an adaptive MAC protocol where this would be possible. We accomplish this by including two protocol modes called the Icarus mode, which is to be used in case of an emergency and the Resync mode which is used when normality is restored. A significant problem at high frequencies is that the beam becomes increasingly narrow and behaves more in a ray like condition. This implies that particularly in an indoor environment it is possible that the beam may be accidentally blocked. In this case the node must be able shift the beam in order to enable communication. We demonstrate three such strategies and offer a comparative analysis.M.S.Committee Chair: Chang, Gee-Kung; Committee Member: Barry , John; Committee Member: Gaylord, To

A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks

In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs

Communication options for protection and control device in Smart Grid applications

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science; in conjunction with the Leaders for Global Operations Program at MIT, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 74-75).Increasing use of electricity, interest in renewable energy sources, and need for a more reliable power grid system are some of the many drivers for the concept of the Smart Grid technology. In order to achieve these goals, one of the critical elements is communication between systems or between the system and human beings. With the decreasing cost of various communication technologies, especially wireless devices and utilities, researchers are increasingly interested in implementing complex two-way communication infrastructures to enhance the quality of the grid. The protection and control relay at the distribution level is one of the key component in enhancing the efficiency, security and reliability of power grid. At present, it may be premature to apply wireless devices to power electronics and to distribution automation, especially for protection and control relays in the distribution level. While fiber technology is still very attractive for protection and control applications in general, wireless technology can bring improvements in user experience applications in the future. The ABB medium voltage group needs to overcome challenges that arise from conservative industry structure, increasing complexity and cost of the product, and needs for higher reliability and security. However, with collaborative efforts among different product groups, the medium voltage group will successfully develop next generation distribution feeder relay.by Hyunsik Eugene Minh.S.M.M.B.A

Advanced Information Systems and Technologies

This book comprises the proceedings of the V International Scientific Conference "Advanced Information Systems and Technologies, AIST-2017". The proceeding papers cover issues related to system analysis and modeling, project management, information system engineering, intelligent data processing computer networking and telecomunications. They will be useful for students, graduate students, researchers who interested in computer science

Advanced Information Systems and Technologies

This book comprises the proceedings of the V International Scientific Conference "Advanced Information Systems and Technologies, AIST-2017". The proceeding papers cover issues related to system analysis and modeling, project management, information system engineering, intelligent data processing computer networking and telecomunications. They will be useful for students, graduate students, researchers who interested in computer science

Adaptation of the IEEE 802.11 protocol for inter-satellite links in LEO satellite networks

Knowledge of the coefficient of thermal expansion (CTE) of a ceramic material is important in many application areas. Whilst the CTE can be measured, it would be useful to be able to predict the expansion behaviour of multiphase materials.. There are several models for the CTE, however, most require a knowledge of the elastic properties of the constituent phases and do not take account ofthe microstructural features of the material. If the CTE could be predicted on the basis of microstructural information, this would then lead to the ability to engineer the microstructure of multiphase ceramic materials to produce acceptable thermal expansion behaviour. To investigate this possibility, magnesia-magnesium aluminate sp~el (MMAS) composites, consisting of a magnesia matrix and magnesium aluminate s~ne'l (MAS) particles, were studied. Having determined a procedure to produce MAS fr alumina and magnesia, via solid state sintering, magnesia-rich compositions wit ~ various magnesia contents were prepared to make the MMAS composites. Further, the l\.1MAS composites prepared from different powders (i.e. from an alumina-magnesia mixture ahd from a magnesia-spinel powder) were compared. Com starch was added into the powder mixtures before sintering to make porous microstructures. Microstructural development and thermal expansion behaviour ofthe MMAS composites were investigated. Microstructures of the MAS and the MMAS composites as well as their porous bodies were quaritified from backscattered electron micrographs in terms of the connectivity of solids i.e. solid contiguity by means of linear intercept counting. Solid contiguity decreased with increasing pore content and varied with pore size, pore shape and pore distribution whereas the phase contiguity depended strongly on the chemical composition and was less influenced by porosity. ' The thermal expansion behaviour of the MAS and the MMAS composites between 100 and 1000 °C was determined experimentally. Variation in the CTE ofthe MAS relates to the degree of spinel formation while the thermal expansion of the MMAS composites depends strongly on phase content. However, the MMAS composites with similar phase compositions but made from different manufacturing processes showed differences in microstructural features and thermal expansion behaviour. Predictions of the CTE values for composites based on a simple rule-of-mixtures (ROM) using volume fraction were compared with the measured data. A conventional ROM accurately predicted the effective CTE of a range of dense alumina-silicon carbide particulate composites but was not very accurate for porous multiphase structures. It provided an upper bound prediction as all experimental values were lower. Hence, the conventional ROM was modified to take account of quantitative microstructural parameters obtained from solid contiguity. The modified ROM predicted lower values and gave a good agreement with the experimental data. Thus, it has been shown that quantitative microstructural information can be used to predict the CTE of multiphase ceramic materials with complex microstructures.EThOS - Electronic Theses Online ServiceGBUnited Kingdo