6 research outputs found

    Design and evaluation of CCA (Cooperative Collision Avoidance) applications for vehicular ad-hoc networks

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    [SPA] El tema central de la Tesis ha versado sobre el diseño y evaluación de aplicaciones para la reducción de la probabilidad de colisión en carretera mediante el uso de conectividad inalámbrica entre vehículos, particularmente en un escenario específico del tráfico rodado: presencia de un obstáculo en la dirección de tránsito que bloquea el paso. Dos enfoques han sido tomados en consideración: utilización de mecanismos de anticipación cooperativa vehículo a vehículo para evadir colisiones mediante frenada, y empleo de esquemas de maniobras de evasión cooperativa en circunstancias donde existe suficiente espacio en la carretera para reorientar las trayectorias y evitar el choque. Se ha hecho uso de herramientas de simulación de redes y dinámica vehicular, y de la teoría matemática de la optimización y de los procesos estocásticos para modelar estos escenarios. Los resultados demuestran que el uso de comunicaciones, junto con sistemas avanzados de inteligencia artificial permitirá en un futuro garantizar cotas de seguridad en carretera nunca antes vistas, incluso en situaciones de riesgo extremo que podrían ser detectadas por uno o más vehículos con tiempos muy cortos de reacción.[ENG] New emerging technologies in vehicular traffic are aimed primarily at improving safety and driving comfort for passengers, by paying special attention to the gradual evermore automation of all aspects of the driving task. In this regard, a promising research perspective considered by the Academia and the Industry is to use communications to build a complex interoperable vehicular network that would serve as a means to provide autonomous robotic-guided vehicles with additional status information that might not be collected from sensors on board. With properly configured processing schemes, this additional stream of information can be used to help vehicles anticipate and react conveniently to potentially risky situations that might cause an accident if not previously considered. Particularly, in this Thesis we use these premises to propose and evaluate collision avoidance policies under two specific fashions: i) Design and evaluation of a Cooperative chain Collision Avoidance (CcCA)1 strategy to reduce the impact of multiple rear-end collisions in a platoon of vehicles when evasive maneuvering is not possible, and ii) Analysis and optimization of different strategies for Cooperative Collision Avoidance (CCA) by evasive maneuvering. The CcCA application allows us to study how communication protocols, both by one-hop transmissions as well as by relaying (multi-hop) schemes, can help reduce the number of accidents, or at least minimize their impact, in cases where vehicles cannot execute sudden maneuvers to skip cars ahead, but only brake. Simulations are validated by using an advanced stochastic model which rigorously describes the behavior of vehicles in this type of situations. Among other aspects, results show that real implementations of CcCA must take into account with special relevance those vehicles that might be humanly driven, and guarantee that during the transition stage (until a complete penetration of the technology is achieved) safety is preserved enough. Regarding CCA for evasive maneuvering, we provide an exhaustive optimization analysis for the calculation of optimum trajectories in cases where vehicles at high speeds are at risk of colliding with one or more obstacles appearing ahead. By reorienting trajectories through the lateral free spaces that might exist between the obstacles and the crash barriers (if the specific scenario allows it), vehicles can avoid crashing and simultaneously improve driving comfort even under such unpredictable circumstances. On the whole, despite much further effort is still required on these matters, results in this Work show that communications can help autonomous vehicles to make decisions in a cooperative fashion that will not only assist individuals to follow the best riding strategy, but also the traffic system as a whole to evolve according to the best possible behavior in terms of safety and comfort.Universidad Politécnica de CartagenaPrograma de doctorado en Tecnologías de la Información y Comunicacione

    Mobile Ad-Hoc Networks

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    Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

    A patient agent controlled customized blockchain based framework for internet of things

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    Although Blockchain implementations have emerged as revolutionary technologies for various industrial applications including cryptocurrencies, they have not been widely deployed to store data streaming from sensors to remote servers in architectures known as Internet of Things. New Blockchain for the Internet of Things models promise secure solutions for eHealth, smart cities, and other applications. These models pave the way for continuous monitoring of patient’s physiological signs with wearable sensors to augment traditional medical practice without recourse to storing data with a trusted authority. However, existing Blockchain algorithms cannot accommodate the huge volumes, security, and privacy requirements of health data. In this thesis, our first contribution is an End-to-End secure eHealth architecture that introduces an intelligent Patient Centric Agent. The Patient Centric Agent executing on dedicated hardware manages the storage and access of streams of sensors generated health data, into a customized Blockchain and other less secure repositories. As IoT devices cannot host Blockchain technology due to their limited memory, power, and computational resources, the Patient Centric Agent coordinates and communicates with a private customized Blockchain on behalf of the wearable devices. While the adoption of a Patient Centric Agent offers solutions for addressing continuous monitoring of patients’ health, dealing with storage, data privacy and network security issues, the architecture is vulnerable to Denial of Services(DoS) and single point of failure attacks. To address this issue, we advance a second contribution; a decentralised eHealth system in which the Patient Centric Agent is replicated at three levels: Sensing Layer, NEAR Processing Layer and FAR Processing Layer. The functionalities of the Patient Centric Agent are customized to manage the tasks of the three levels. Simulations confirm protection of the architecture against DoS attacks. Few patients require all their health data to be stored in Blockchain repositories but instead need to select an appropriate storage medium for each chunk of data by matching their personal needs and preferences with features of candidate storage mediums. Motivated by this context, we advance third contribution; a recommendation model for health data storage that can accommodate patient preferences and make storage decisions rapidly, in real-time, even with streamed data. The mapping between health data features and characteristics of each repository is learned using machine learning. The Blockchain’s capacity to make transactions and store records without central oversight enables its application for IoT networks outside health such as underwater IoT networks where the unattended nature of the nodes threatens their security and privacy. However, underwater IoT differs from ground IoT as acoustics signals are the communication media leading to high propagation delays, high error rates exacerbated by turbulent water currents. Our fourth contribution is a customized Blockchain leveraged framework with the model of Patient-Centric Agent renamed as Smart Agent for securely monitoring underwater IoT. Finally, the smart Agent has been investigated in developing an IoT smart home or cities monitoring framework. The key algorithms underpinning to each contribution have been implemented and analysed using simulators.Doctor of Philosoph

    Building the Future Internet through FIRE

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    The Internet as we know it today is the result of a continuous activity for improving network communications, end user services, computational processes and also information technology infrastructures. The Internet has become a critical infrastructure for the human-being by offering complex networking services and end-user applications that all together have transformed all aspects, mainly economical, of our lives. Recently, with the advent of new paradigms and the progress in wireless technology, sensor networks and information systems and also the inexorable shift towards everything connected paradigm, first as known as the Internet of Things and lately envisioning into the Internet of Everything, a data-driven society has been created. In a data-driven society, productivity, knowledge, and experience are dependent on increasingly open, dynamic, interdependent and complex Internet services. The challenge for the Internet of the Future design is to build robust enabling technologies, implement and deploy adaptive systems, to create business opportunities considering increasing uncertainties and emergent systemic behaviors where humans and machines seamlessly cooperate

    Building the Future Internet through FIRE

    Get PDF
    The Internet as we know it today is the result of a continuous activity for improving network communications, end user services, computational processes and also information technology infrastructures. The Internet has become a critical infrastructure for the human-being by offering complex networking services and end-user applications that all together have transformed all aspects, mainly economical, of our lives. Recently, with the advent of new paradigms and the progress in wireless technology, sensor networks and information systems and also the inexorable shift towards everything connected paradigm, first as known as the Internet of Things and lately envisioning into the Internet of Everything, a data-driven society has been created. In a data-driven society, productivity, knowledge, and experience are dependent on increasingly open, dynamic, interdependent and complex Internet services. The challenge for the Internet of the Future design is to build robust enabling technologies, implement and deploy adaptive systems, to create business opportunities considering increasing uncertainties and emergent systemic behaviors where humans and machines seamlessly cooperate
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