53 research outputs found

    Achieving reliable and enhanced communication in vehicular ad hoc networks (VANETs)

    Get PDF
    A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirement for the degree of Doctor of PhilosophyWith the envisioned age of Internet of Things (IoTs), different aspects of Intelligent Transportation System (ITS) will be linked so as to advance road transportation safety, ease congestion of road traffic, lessen air pollution, improve passenger transportation comfort and significantly reduce road accidents. In vehicular networks, regular exchange of current position, direction, speed, etc., enable mobile vehicle to foresee an imminent vehicle accident and notify the driver early enough in order to take appropriate action(s) or the vehicle on its own may take adequate preventive measures to avert the looming accident. Actualizing this concept requires use of shared media access protocol that is capable of guaranteeing reliable and timely broadcast of safety messages. This dissertation investigates the use of Network Coding (NC) techniques to enrich the content of each transmission and ensure improved high reliability of the broadcasted safety messages with less number of retransmissions. A Code Aided Retransmission-based Error Recovery (CARER) protocol is proposed. In order to avoid broadcast storm problem, a rebroadcasting vehicle selection metric η, is developed, which is used to select a vehicle that will rebroadcast the received encoded message. Although the proposed CARER protocol demonstrates an impressive performance, the level of incurred overhead is fairly high due to the use of complex rebroadcasting vehicle selection metric. To resolve this issue, a Random Network Coding (RNC) and vehicle clustering based vehicular communication scheme with low algorithmic complexity, named Reliable and Enhanced Cooperative Cross-layer MAC (RECMAC) scheme, is proposed. The use of this clustering technique enables RECMAC to subdivide the vehicular network into small manageable, coordinated clusters which further improve transmission reliability and minimise negative impact of network overhead. Similarly, a Cluster Head (CH) selection metric ℱ(\u1d457) is designed, which is used to determine and select the most suitably qualified candidate to become the CH of a particular cluster. Finally, in order to investigate the impact of available radio spectral resource, an in-depth study of the required amount of spectrum sufficient to support high transmission reliability and minimum latency requirements of critical road safety messages in vehicular networks was carried out. The performance of the proposed schemes was clearly shown with detailed theoretical analysis and was further validated with simulation experiments

    Intelligent Sensor Networks

    Get PDF
    In the last decade, wireless or wired sensor networks have attracted much attention. However, most designs target general sensor network issues including protocol stack (routing, MAC, etc.) and security issues. This book focuses on the close integration of sensing, networking, and smart signal processing via machine learning. Based on their world-class research, the authors present the fundamentals of intelligent sensor networks. They cover sensing and sampling, distributed signal processing, and intelligent signal learning. In addition, they present cutting-edge research results from leading experts

    Recent Developments on Mobile Ad-Hoc Networks and Vehicular Ad-Hoc Networks

    Get PDF
    This book presents collective works published in the recent Special Issue (SI) entitled "Recent Developments on Mobile Ad-Hoc Networks and Vehicular Ad-Hoc Networks”. These works expose the readership to the latest solutions and techniques for MANETs and VANETs. They cover interesting topics such as power-aware optimization solutions for MANETs, data dissemination in VANETs, adaptive multi-hop broadcast schemes for VANETs, multi-metric routing protocols for VANETs, and incentive mechanisms to encourage the distribution of information in VANETs. The book demonstrates pioneering work in these fields, investigates novel solutions and methods, and discusses future trends in these field

    Resilience-Building Technologies: State of Knowledge -- ReSIST NoE Deliverable D12

    Get PDF
    This document is the first product of work package WP2, "Resilience-building and -scaling technologies", in the programme of jointly executed research (JER) of the ReSIST Network of Excellenc

    Internet sharing in community networks

    Get PDF
    Cotutela Universitat Politècnica de Catalunya i Instituto Superior TécnicoThe majority of the world's population does not have any or adequate Internet access. This implies that the Internet cannot provide universal service, reaching everyone without discrimination. Global access to the Internet for all requires the expansion of network infrastructures and a dramatic reduction in Internet access costs especially in less developed geographical regions. Local communities come together to build their own network infrastructures, known as Community Networks, and provide accessible and affordable local and Internet inter-networking. Sharing resources, such as infrastructure or Internet access, is encouraged at all levels, in order to lower the cost of connectivity and services. Communities can develop their own network infrastructures as a commons, using several interconnected sub-networks when the scale requires it, and sharing several Internet gateways among their participants. Shared Internet access is offered through web proxy gateways, where individuals or organisations share the full or spare capacity of their Internet connections with other participants. However, these gateway nodes may be overloaded by the demand, and their Internet capacity may degrade due to lack of regulation. This thesis investigates whether shared Internet access in community networks can be utilized to provide universal Internet access. As a first step in this direction, in this thesis we explored characteristics, limitations and usability of a concrete shared Internet Web proxy service in community networks. Based on our findings we studied and proposed mechanisms to improve the user experience and fairness of Internet sharing Web proxy services in community networks, without introducing significant overhead to the network and other services. More specifically, we proposed a scalable client-side Internet gateway selection mechanism suitable for heterogeneous environments such as community networks. Finally, we studied and proposed techniques for sharing spare Internet capacity without deteriorating the contributors' performance.La mayoría de la población mundial no tiene ningún o un adecuado acceso a Internet. Esto implica que Internet no puede prestar un servicio universal, llegando a todos sin discriminación. El acceso global a Internet para todos requiere una drástica reducción de los costos de acceso a Internet, especialmente en zonas geográficas y poblaciones menos desarrolladas. Las comunidades locales se organizan para construir sus propias infraestructuras de red, conocidas como redes comunitarias, y proporcionan interconexión local y con Internet de forma accesible y asequible. Se fomenta la compartición de recursos, como la infraestructura o el acceso a Internet, para reducir el coste de la conectividad y los servicios. Las comunidades pueden desarrollar sus propias infraestructuras de red como un recurso común, utilizando varias subredes interconectadas dado su tamaño, y compartiendo varias pasarelas de Internet entre sus participantes. El acceso compartido a Internet se ofrece a través de pasarelas que son proxy web, donde los participantes o las organizaciones comparten la capacidad total o excedente de su conexión a Internet con otros participantes. Sin embargo, estas pasarelas pueden saturarse por la demanda, y su capacidad de acceso a Internet se puede degradar debido la falta de regulación. Esta tesis investiga si las redes comunitarias se pueden utilizar para proporcionar acceso universal a Internet. Como primer paso en esta dirección, exploramos las características, limitaciones y usabilidad de un servicio concreto de acceso compartido a Internet con proxies web en una red comunitaria. Sobre la base de nuestros hallazgos, estudiamos y proponemos mecanismos para mejorar la experiencia del usuario y la equitatividad de la compartición, sin introducir una sobrecarga significativa en la red y a otros servicios. Más específicamente, proponemos un mecanismo escalable de selección de pasarela a Internet del lado del cliente, adecuado para entornos heterogéneos como las redes comunitarias. Además, estudiamos y proponemos técnicas para compartir la capacidad de Internet sin deteriorar el desempeño de los participantes que contribuyen.Postprint (published version

    Modern Socio-Technical Perspectives on Privacy

    Get PDF
    This open access book provides researchers and professionals with a foundational understanding of online privacy as well as insight into the socio-technical privacy issues that are most pertinent to modern information systems, covering several modern topics (e.g., privacy in social media, IoT) and underexplored areas (e.g., privacy accessibility, privacy for vulnerable populations, cross-cultural privacy). The book is structured in four parts, which follow after an introduction to privacy on both a technical and social level: Privacy Theory and Methods covers a range of theoretical lenses through which one can view the concept of privacy. The chapters in this part relate to modern privacy phenomena, thus emphasizing its relevance to our digital, networked lives. Next, Domains covers a number of areas in which privacy concerns and implications are particularly salient, including among others social media, healthcare, smart cities, wearable IT, and trackers. The Audiences section then highlights audiences that have traditionally been ignored when creating privacy-preserving experiences: people from other (non-Western) cultures, people with accessibility needs, adolescents, and people who are underrepresented in terms of their race, class, gender or sexual identity, religion or some combination. Finally, the chapters in Moving Forward outline approaches to privacy that move beyond one-size-fits-all solutions, explore ethical considerations, and describe the regulatory landscape that governs privacy through laws and policies. Perhaps even more so than the other chapters in this book, these chapters are forward-looking by using current personalized, ethical and legal approaches as a starting point for re-conceptualizations of privacy to serve the modern technological landscape. The book’s primary goal is to inform IT students, researchers, and professionals about both the fundamentals of online privacy and the issues that are most pertinent to modern information systems. Lecturers or teacherscan assign (parts of) the book for a “professional issues” course. IT professionals may select chapters covering domains and audiences relevant to their field of work, as well as the Moving Forward chapters that cover ethical and legal aspects. Academicswho are interested in studying privacy or privacy-related topics will find a broad introduction in both technical and social aspects

    Modern Socio-Technical Perspectives on Privacy

    Get PDF
    This open access book provides researchers and professionals with a foundational understanding of online privacy as well as insight into the socio-technical privacy issues that are most pertinent to modern information systems, covering several modern topics (e.g., privacy in social media, IoT) and underexplored areas (e.g., privacy accessibility, privacy for vulnerable populations, cross-cultural privacy). The book is structured in four parts, which follow after an introduction to privacy on both a technical and social level: Privacy Theory and Methods covers a range of theoretical lenses through which one can view the concept of privacy. The chapters in this part relate to modern privacy phenomena, thus emphasizing its relevance to our digital, networked lives. Next, Domains covers a number of areas in which privacy concerns and implications are particularly salient, including among others social media, healthcare, smart cities, wearable IT, and trackers. The Audiences section then highlights audiences that have traditionally been ignored when creating privacy-preserving experiences: people from other (non-Western) cultures, people with accessibility needs, adolescents, and people who are underrepresented in terms of their race, class, gender or sexual identity, religion or some combination. Finally, the chapters in Moving Forward outline approaches to privacy that move beyond one-size-fits-all solutions, explore ethical considerations, and describe the regulatory landscape that governs privacy through laws and policies. Perhaps even more so than the other chapters in this book, these chapters are forward-looking by using current personalized, ethical and legal approaches as a starting point for re-conceptualizations of privacy to serve the modern technological landscape. The book’s primary goal is to inform IT students, researchers, and professionals about both the fundamentals of online privacy and the issues that are most pertinent to modern information systems. Lecturers or teacherscan assign (parts of) the book for a “professional issues” course. IT professionals may select chapters covering domains and audiences relevant to their field of work, as well as the Moving Forward chapters that cover ethical and legal aspects. Academicswho are interested in studying privacy or privacy-related topics will find a broad introduction in both technical and social aspects

    Discrete Event Simulations

    Get PDF
    Considered by many authors as a technique for modelling stochastic, dynamic and discretely evolving systems, this technique has gained widespread acceptance among the practitioners who want to represent and improve complex systems. Since DES is a technique applied in incredibly different areas, this book reflects many different points of view about DES, thus, all authors describe how it is understood and applied within their context of work, providing an extensive understanding of what DES is. It can be said that the name of the book itself reflects the plurality that these points of view represent. The book embraces a number of topics covering theory, methods and applications to a wide range of sectors and problem areas that have been categorised into five groups. As well as the previously explained variety of points of view concerning DES, there is one additional thing to remark about this book: its richness when talking about actual data or actual data based analysis. When most academic areas are lacking application cases, roughly the half part of the chapters included in this book deal with actual problems or at least are based on actual data. Thus, the editor firmly believes that this book will be interesting for both beginners and practitioners in the area of DES

    High-Performance Modelling and Simulation for Big Data Applications

    Get PDF
    This open access book was prepared as a Final Publication of the COST Action IC1406 “High-Performance Modelling and Simulation for Big Data Applications (cHiPSet)“ project. Long considered important pillars of the scientific method, Modelling and Simulation have evolved from traditional discrete numerical methods to complex data-intensive continuous analytical optimisations. Resolution, scale, and accuracy have become essential to predict and analyse natural and complex systems in science and engineering. When their level of abstraction raises to have a better discernment of the domain at hand, their representation gets increasingly demanding for computational and data resources. On the other hand, High Performance Computing typically entails the effective use of parallel and distributed processing units coupled with efficient storage, communication and visualisation systems to underpin complex data-intensive applications in distinct scientific and technical domains. It is then arguably required to have a seamless interaction of High Performance Computing with Modelling and Simulation in order to store, compute, analyse, and visualise large data sets in science and engineering. Funded by the European Commission, cHiPSet has provided a dynamic trans-European forum for their members and distinguished guests to openly discuss novel perspectives and topics of interests for these two communities. This cHiPSet compendium presents a set of selected case studies related to healthcare, biological data, computational advertising, multimedia, finance, bioinformatics, and telecommunications
    corecore