12 research outputs found

    Cooperative Radio Communications for Green Smart Environments

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    The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: ‱ Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments‱ Measurements, characterization, and modelling of radio channels beyond 4G networks‱ Key issues in Vehicle (V2X) communication‱ Wireless Body Area Networks, including specific Radio Channel Models for WBANs‱ Energy efficiency and resource management enhancements in Radio Access Networks‱ Definitions and models for the virtualised and cloud RAN architectures‱ Advances on feasible indoor localization and tracking techniques‱ Recent findings and innovations in antenna systems for communications‱ Physical Layer Network Coding for next generation wireless systems‱ Methods and techniques for MIMO Over the Air (OTA) testin

    Cooperative Radio Communications for Green Smart Environments

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    The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: ‱ Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments‱ Measurements, characterization, and modelling of radio channels beyond 4G networks‱ Key issues in Vehicle (V2X) communication‱ Wireless Body Area Networks, including specific Radio Channel Models for WBANs‱ Energy efficiency and resource management enhancements in Radio Access Networks‱ Definitions and models for the virtualised and cloud RAN architectures‱ Advances on feasible indoor localization and tracking techniques‱ Recent findings and innovations in antenna systems for communications‱ Physical Layer Network Coding for next generation wireless systems‱ Methods and techniques for MIMO Over the Air (OTA) testin

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

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    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

    Radio Communications

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    In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modiïŹed our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the ïŹeld of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks

    Recent Advances in Wireless Communications and Networks

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    This book focuses on the current hottest issues from the lowest layers to the upper layers of wireless communication networks and provides "real-time" research progress on these issues. The authors have made every effort to systematically organize the information on these topics to make it easily accessible to readers of any level. This book also maintains the balance between current research results and their theoretical support. In this book, a variety of novel techniques in wireless communications and networks are investigated. The authors attempt to present these topics in detail. Insightful and reader-friendly descriptions are presented to nourish readers of any level, from practicing and knowledgeable communication engineers to beginning or professional researchers. All interested readers can easily find noteworthy materials in much greater detail than in previous publications and in the references cited in these chapters

    Localisation en intérieur et gestion de la mobilité dans les réseaux sans fils hétérogÚnes émergents

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    Au cours des derniĂšres dĂ©cennies, nous avons Ă©tĂ© tĂ©moins d'une Ă©volution considĂ©rable dans l'informatique mobile, rĂ©seau sans fil et des appareils portatifs. Dans les rĂ©seaux de communication Ă  venir, les utilisateurs devraient ĂȘtre encore plus mobiles exigeant une connectivitĂ© omniprĂ©sente Ă  diffĂ©rentes applications qui seront de prĂ©fĂ©rence au courant de leur contexte. Certes, les informations de localisation dans le cadre de leur contexte est d'une importance primordiale Ă  la fois la demande et les perspectives du rĂ©seau. Depuis l'application ou de point de vue utilisateur, la fourniture de services peut mettre Ă  jour si l'adaptation au contexte de l'utilisateur est activĂ©e. Du point de vue du rĂ©seau, des fonctionnalitĂ©s telles que le routage, la gestion de transfert, l'allocation des ressources et d'autres peuvent Ă©galement bĂ©nĂ©ficier si l'emplacement de l'utilisateur peuvent ĂȘtre suivis ou mĂȘme prĂ©dit. Dans ce contexte, nous nous concentrons notre attention sur la localisation Ă  l'intĂ©rieur et de la prĂ©vision transfert qui sont des composants indispensables Ă  la rĂ©ussite ultime de l'Ăšre de la communication omniprĂ©sente envisagĂ©. Alors que les systĂšmes de positionnement en plein air ont dĂ©jĂ  prouvĂ© leur potentiel dans un large Ă©ventail d'applications commerciales, le chemin vers un systĂšme de localisation Ă  l'intĂ©rieur de succĂšs est reconnu pour ĂȘtre beaucoup plus difficile, principalement en raison des caractĂ©ristiques difficiles Ă  l'intĂ©rieur et l'exigence d'une plus grande prĂ©cision. De mĂȘme, la gestion de transfert dans le futur des rĂ©seaux hĂ©tĂ©rogĂšnes sans fil est beaucoup plus difficile que dans les rĂ©seaux traditionnels homogĂšnes. RĂ©gimes de procĂ©dure de transfert doit ĂȘtre sans faille pour la rĂ©union strictes de qualitĂ© de service (QoS) des applications futures et fonctionnel malgrĂ© la diversitĂ© des caractĂ©ristiques de fonctionnement des diffĂ©rentes technologies. En outre, les dĂ©cisions transfert devraient ĂȘtre suffisamment souples pour tenir compte des prĂ©fĂ©rences utilisateur d'un large Ă©ventail de critĂšres proposĂ©s par toutes les technologies. L'objectif principal de cette thĂšse est de mettre au point prĂ©cis, l'heure et l'emplacement de puissance et de systĂšmes efficaces de gestion de transfert afin de mieux satisfaire applications sensibles au contexte et mobiles. Pour obtenir une localisation Ă  l'intĂ©rieur, le potentiel de rĂ©seau local sans fil (WLAN) et Radio Frequency Identification (RFID) que l'emplacement autonome technologies de dĂ©tection sont d'abord Ă©tudiĂ©s par des essais plusieurs algorithmes et paramĂštres dans un banc d'essai expĂ©rimental rĂ©el ou par de nombreuses simulations, alors que leurs lacunes sont Ă©galement Ă©tĂ© identifiĂ©s. Leur intĂ©gration dans une architecture commune est alors proposĂ©e afin de combiner leurs principaux avantages et surmonter leurs limitations. La supĂ©rioritĂ© des performances du systĂšme de synergie sur le stand alone homologues est validĂ©e par une analyse approfondie. En ce qui concerne la tĂąche de gestion transfert, nous repĂ©rer que la sensibilitĂ© au contexte peut aussi amĂ©liorer la fonctionnalitĂ© du rĂ©seau. En consĂ©quence, deux de tels systĂšmes qui utilisent l'information obtenue Ă  partir des systĂšmes de localisation sont proposĂ©es. Le premier schĂ©ma repose sur un dĂ©ploiement tag RFID, comme notre architecture de positionnement RFID, et en suivant la scĂšne WLAN analyse du concept de positionnement, prĂ©dit l'emplacement rĂ©seau de la prochaine couche, c'est Ă  dire le prochain point de fixation sur le rĂ©seau. Le second rĂ©gime repose sur une approche intĂ©grĂ©e RFID et sans fil de capteur / actionneur Network (WSAN) de dĂ©ploiement pour la localisation des utilisateurs physiques et par la suite pour prĂ©dire la prochaine leur point de transfert Ă  deux couches de liaison et le rĂ©seau. Etre indĂ©pendant de la technologie d'accĂšs sans fil principe sous-jacent, les deux rĂ©gimes peuvent ĂȘtre facilement mises en Ɠuvre dans des rĂ©seaux hĂ©tĂ©rogĂšnes [...]Over the last few decades, we have been witnessing a tremendous evolution in mobile computing, wireless networking and hand-held devices. In the future communication networks, users are anticipated to become even more mobile demanding for ubiquitous connectivity to different applications which will be preferably aware of their context. Admittedly, location information as part of their context is of paramount importance from both application and network perspectives. From application or user point of view, service provision can upgrade if adaptation to the user's context is enabled. From network point of view, functionalities such as routing, handoff management, resource allocation and others can also benefit if user's location can be tracked or even predicted. Within this context, we focus our attention on indoor localization and handoff prediction which are indispensable components towards the ultimate success of the envisioned pervasive communication era. While outdoor positioning systems have already proven their potential in a wide range of commercial applications, the path towards a successful indoor location system is recognized to be much more difficult, mainly due to the harsh indoor characteristics and requirement for higher accuracy. Similarly, handoff management in the future heterogeneous wireless networks is much more challenging than in traditional homogeneous networks. Handoff schemes must be seamless for meeting strict Quality of Service (QoS) requirements of the future applications and functional despite the diversity of operation features of the different technologies. In addition, handoff decisions should be flexible enough to accommodate user preferences from a wide range of criteria offered by all technologies. The main objective of this thesis is to devise accurate, time and power efficient location and handoff management systems in order to satisfy better context-aware and mobile applications. For indoor localization, the potential of Wireless Local Area Network (WLAN) and Radio Frequency Identification (RFID) technologies as standalone location sensing technologies are first studied by testing several algorithms and metrics in a real experimental testbed or by extensive simulations, while their shortcomings are also identified. Their integration in a common architecture is then proposed in order to combine their key benefits and overcome their limitations. The performance superiority of the synergetic system over the stand alone counterparts is validated via extensive analysis. Regarding the handoff management task, we pinpoint that context awareness can also enhance the network functionality. Consequently, two such schemes which utilize information obtained from localization systems are proposed. The first scheme relies on a RFID tag deployment, alike our RFID positioning architecture, and by following the WLAN scene analysis positioning concept, predicts the next network layer location, i.e. the next point of attachment to the network. The second scheme relies on an integrated RFID and Wireless Sensor/Actuator Network (WSAN) deployment for tracking the users' physical location and subsequently for predicting next their handoff point at both link and network layers. Being independent of the underlying principle wireless access technology, both schemes can be easily implemented in heterogeneous networks. Performance evaluation results demonstrate the advantages of the proposed schemes over the standard protocols regarding prediction accuracy, time latency and energy savingsEVRY-INT (912282302) / SudocSudocFranceF

    Energy Efficient and Cooperative Solutions for Next-Generation Wireless Networks

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    Energy efficiency is increasingly important for next-generation wireless systems due to the limited battery resources of mobile clients. While fourth generation cellular standards emphasize low client battery consumption, existing techniques do not explicitly focus on reducing power that is consumed when a client is actively communicating with the network. Based on high data rate demands of modern multimedia applications, active mode power consumption is expected to become a critical consideration for the development and deployment of future wireless technologies. Another reason for focusing more attention on energy efficient studies is given by the relatively slow progress in battery technology and the growing quality of service requirements of multimedia applications. The disproportion between demanded and available battery capacity is becoming especially significant for small-scale mobile client devices, where wireless power consumption dominates within the total device power budget. To compensate for this growing gap, aggressive improvements in all aspects of wireless system design are necessary. Recent work in this area indicates that joint link adaptation and resource allocation techniques optimizing energy efficient metrics can provide a considerable gain in client power consumption. Consequently, it is crucial to adapt state-of-the-art energy efficient approaches for practical use, as well as to illustrate the pros and cons associated with applying power-bandwidth optimization to improve client energy efficiency and develop insights for future research in this area. This constitutes the first objective of the present research. Together with energy efficiency, next-generation cellular technologies are emphasizing stronger support for heterogeneous multimedia applications. Since the integration of diverse services within a single radio platform is expected to result in higher operator profits and, at the same time, reduce network management expenses, intensive research efforts have been invested into design principles of such networks. However, as wireless resources are limited and shared by clients, service integration may become challenging. A key element in such systems is the packet scheduler, which typically helps ensure that the individual quality of service requirements of wireless clients are satisfied. In contrastingly different distributed wireless environments, random multiple access protocols are beginning to provide mechanisms for statistical quality of service assurance. However, there is currently a lack of comprehensive analytical frameworks which allow reliable control of the quality of service parameters for both cellular and local area networks. Providing such frameworks is therefore the second objective of this thesis. Additionally, the study addresses the simultaneous operation of a cellular and a local area network in spectrally intense metropolitan deployments and solves some related problems. Further improving the performance of battery-driven mobile clients, cooperative communications are sought as a promising and practical concept. In particular, they are capable of mitigating the negative effects of fading in a wireless channel and are thus expected to enhance next-generation cellular networks in terms of client spectral and energy efficiencies. At the cell edges or in areas missing any supportive relaying infrastructure, client-based cooperative techniques are becoming even more important. As such, a mobile client with poor channel quality may take advantage of neighboring clients which would relay data on its behalf. The key idea behind the concept of client relay is to provide flexible and distributed control over cooperative communications by the wireless clients themselves. By contrast to fully centralized control, this is expected to minimize overhead protocol signaling and hence ensure simpler implementation. Compared to infrastructure relay, client relay will also be cheaper to deploy. Developing the novel concept of client relay, proposing simple and feasible cooperation protocols, and analyzing the basic trade-offs behind client relay functionality become the third objective of this research. Envisioning the evolution of cellular technologies beyond their fourth generation, it appears important to study a wireless network capable of supporting machine-to-machine applications. Recent standardization documents cover a plethora of machine-to-machine use cases, as they also outline the respective technical requirements and features according to the application or network environment. As follows from this activity, a smart grid is one of the primary machine-to-machine use cases that involves meters autonomously reporting usage and alarm information to the grid infrastructure to help reduce operational cost, as well as regulate a customer's utility usage. The preliminary analysis of the reference smart grid scenario indicates weak system architecture components. For instance, the large population of machine-to-machine devices may connect nearly simultaneously to the wireless infrastructure and, consequently, suffer from excessive network entry delays. Another concern is the performance of cell-edge machine-to-machine devices with weak wireless links. Therefore, mitigating the above architecture vulnerabilities and improving the performance of future smart grid deployments is the fourth objective of this thesis. Summarizing, this thesis is generally aimed at the improvement of energy efficient properties of mobile devices in next-generation wireless networks. The related research also embraces a novel cooperation technique where clients may assist each other to increase per-client and network-wide performance. Applying the proposed solutions, the operation time of mobile clients without recharging may be increased dramatically. Our approach incorporates both analytical and simulation components to evaluate complex interactions between the studied objectives. It brings important conclusions about energy efficient and cooperative client behaviors, which is crucial for further development of wireless communications technologies

    Intelligent Circuits and Systems

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    ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.  This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering
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