6 research outputs found

    Traffic differentiation support in vehicular delay-tolerant networks

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    Vehicular Delay-Tolerant Networking (VDTN) is a Delay-Tolerant Network (DTN) based architecture concept for transit networks, where vehicles movement and their bundle relaying service is opportunistically exploited to enable non-real time applications, under environments prone to connectivity disruptions, network partitions and potentially long delays. In VDTNs, network resources may be limited, for instance due to physical constraints of the network nodes. In order to be able to prioritize applications traffic according to its requirements in such constrained scenarios, traffic differentiation mechanisms must be introduced at the VDTN architecture. This work considers a priority classes of service (CoS) model and investigates how different buffer management strategies can be combined with drop and scheduling policies, to provide strict priority based services, or to provide custom allocation of network resources. The efficiency and tradeoffs of these proposals is evaluated through extensive simulation.Part of this work has been supported by Instituto de Telecomunicações, Next Generation Networks and Applications Group (NetGNA), Portugal, in the framework of the Project VDTN@Lab, and by the Euro-NF Network of Excellence of the Seventh Framework Programme of EU

    A probabilistic VDTN routing scheme based on hybrid swarm-based approach

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    The probabilistic Delay Tolerant Network (DTN) routing has been adjusted for vehicular network (VANET) routing through numerous works exploiting the historic routing profile of nodes to forward bundles through better Store-Carry-and-Forward (SCF) relay nodes. In this paper, we propose a new hybrid swarm-inspired probabilistic Vehicular DTN (VDTN) router to optimize the next-SCF vehicle selection using the combination of two bio-metaheuristic techniques called the Firefly Algorithm (FA) and the Glowworm Swarm Optimization (GSO). The FA-based strategy exploits the stochastic intelligence of fireflies in moving toward better individuals, while the GSO-based strategy mimics the movement of glowworm towards better area for displacing and food foraging. Both FA and GSO are executed simultaneously on each node to track better SCF vehicles towards each bundle’s destination. A geography-based recovery method is performed in case no better SCF vehicles are found using the hybrid FA–GSO approach. The proposed FA–GSO VDTN scheme is compared to ProPHET and GeoSpray routers. The simulation results indicated optimized bundles flooding levels and higher profitability of combined delivery delay and delivery probability.info:eu-repo/semantics/publishedVersio

    Wireless sensor networks for building robotic paths: a survey of problems and restrictions

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    The conjugation of small nodes with sensing, communication and processing capabilities allows for the creation of wireless sensor networks (WSNs). These networks can be deployed to measure a very wide range of environmental phenomena and send data from remote locations back to users. They offer new and exciting possibilities for applications and research. This paper presents the background of WSNs by firstly exploring the different fields applications, with examples for each of these fields, then the challenges faced by these networks in areas such as energy-efficiency, node localization, node deployment, limited storage and routing. It aims at explaining each issue and giving solutions that have been proposed in the research literature. Finally, the paper proposes a practical scenario of deploying a WSN by autonomous robot path construction. The requirements for such a scenario and the open issues that can be tackled by it are exposed, namely the issues of associated with measuring RSSI, the degree of autonomy of the robot and connectivity restoration.info:eu-repo/semantics/publishedVersio

    Protótipo para recolha de informação de apoio à gestão de resíduos

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    Este artigo apresenta o desenho e implementação de um protótipo para a empresa EVOX Technologies, para obtenção de informação sobre níveis de enchimento, anomalias e outros alertas relacionados com contentores de resíduos urbanos, aquando da recolha destes pelos cantoneiros. São descritas as tecnologias adotadas a nível de hardware e software para implementação do protótipo baseado num LCD que comunica com um sistema de gestão de resíduos. Constitui uma alternativa viável e vantajosa à solução tradicional baseada numa botoneira simples e estática, contribuindo para a gestão em tempo real e para a redução dos gastos logísticos e de implementação da gestão inteligente de resíduos.info:eu-repo/semantics/publishedVersio

    Network management and monitoring solutions for vehicular networks: a survey

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    Vehicular networks are emerging as a promising technology that enables reliable and low-cost solutions for intelligent transport systems (ITSs), mainly due to their enormous potential to be considered for multiple purposes and scenarios. These networks are characterized by unique and challenging features such as packet fragmentation, low node density, short contact duration, and network disruption. These features may result in the absence of a path between the source and destination nodes, which is one of the most challenging issues faced by this type of network. To overcome some of these problems, it is necessary to provide vehicular networks with sophisticated tools or methodologies to implement monitoring and management operations. However, designing efficient solutions for this type of network is not an easy task due to its particular characteristics. This paper elaborates on a comprehensive survey focusing on promising proposals to deal with monitoring and management functionalities in vehicular networks. This work aims not only to present the state of the art on monitoring and management solutions but also to analyze their benefits and drawbacks, identify open issues, and provide guidelines for further contributions.info:eu-repo/semantics/publishedVersio

    An opportunistic routing solution to monitor isolated elderly people in rural areas

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    Countries are experiencing a global population ageing. It is estimated that the percentage of third age people will notably increase in next decades, implying a difficult challenge to society. Rural areas are the most affected locations by these conditions. Currently, small vil- lages are facing an increasing ageing of population where almost 40% of inhabitants are over 65. Medical needs are one of the most relevant aspects in this context. This factor, in conjunction with other reasons such as loneliness, motivates technological solutions. Despite this, Inter- net is not accessible from rural and low income areas, due to the lack of interest from the operator side to invest in these locations. In this paper, an opportunistic routing solution based on BLE is proposed, with the aim of monitoring loneliness population in order to detect potential emergencies.info:eu-repo/semantics/publishedVersio
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