28 research outputs found

    RAHIM: Robust Adaptive Approach Based on Hierarchical Monitoring Providing Trust Aggregation for Wireless Sensor Networks

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    In-network data aggregation has a great impact on the energy consumption in large-scale wireless sensor networks. However, the resource constraints and vulnerable deployment environments challenge the application of this technique in terms of security and efficiency. A compromised node may forge arbitrary aggregation value and mislead the base station into trusting a false reading. In this paper, we present RAHIM, a reactive defense to secure data aggregation scheme in cluster-based wireless sensor networks. The proposed scheme is based on a novel application of adaptive hierarchical level of monitoring providing accuracy of data aggregation result in lightweight manner, even if all aggregator nodes and a part of sensors are compromised in the network

    Distributed Fault-Tolerant Algorithm for Wireless Sensor Networks

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    Wireless Sensor Networks (WSNs) are a set of tiny autonomous and interconnected devices. These nodes are scattered in a region of interest to collect information about the surrounding environment depending on the intended application. In many applications, the network is deployed in harsh environments such as battlefield where the nodes are susceptible to damage. In addition, nodes may fail due to energy depletion and breakdown in the onboard electronics. The failure of nodes may leave some areas uncovered and degrade the fidelity of the collected data. Therefore, establish a fault-tolerant mechanism is very crucial. Given the resource-constrained setup, this mechanism should impose the least overhead and performance impact. This paper focuses on recovery process after a fault detection phase in WSNs. We present an algorithm to recover faulty node called Distributed Fault-Tolerant Algorithm (DFTA).The performance evaluation is tested through simulation to evaluate some factors such as: Packet delivery ratio, control overhead, memory overhead and fault recovery delay. We compared our results with referenced algorithm: Fault Detection in Wireless Sensor Networks (FDWSN), and found that our DFTA performance outperforms that of FDWSN

    Routage avec qualité de service des réseaux Mesh IEEE 802.11s

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    Le routage et la qualité de service (QoS) demeurent un défi majeur pour améliorer les performances des réseaux mesh IEEE 802.11s WMNs). C est dans ce cadre que s inscrivent les contributions de notre travail de thèse, qui consiste à améliorer le routage et la qualité de service (QoS) dans les réseaux WMNs. Afin d apporter une solution à ce défi et d améliorer la qualité de service de trafic temps réel, nous proposons une nouvelle méthode basée sur la réservation de la bande passante combinée avec le protocole HWMP (Hybrid Wireless Mesh Protocol), du fait que ce dernier ne supporte pas la QoS (qualité de service). Cette nouvelle méthode est nommée MBRWMN (Multi-hop Bandwidth Reservation in WMN), elle définit une technique de réservation de la bande passante et une nouvelle métrique nommée WAM (Weighted Airtim Metric) pour le protocole HWMP, MBRWMN vise à garantir saut par saut la bande passante requise pour le trafic temps réel à l aide d un contrôle d admission. Cependant pour diminuer le délai de bout-en-bout et d augmenter le débit, nous proposons une nouvelle métrique basée sur la diversité des canaux combinée avec le délai de transmission des paquets. Cette nouvelle métrique de routage nommée NMH (New Metric for HWMP protocol) est utilisée par le protocole HWMP. La solution que nous avons proposée, vise à fournir une meilleure route en calculant saut par saut, la valeur de la métrique NMH implémentée par le protocole HWMP. Dans le même objectif et pour améliorer les performances du réseau, nous avons proposé la méthode ODCAM (On Demand Channel Assignment Method), qui consiste à mettre en place un mécanisme de diversité de canaux, basé sur une méthode hybride d affectation des canaux. Dans le but de diminuer le délai de bout-en-bout et d augmenter le débit, notre méthode vise à calculer le long de la route entre la source et la destination, la valeur de la métrique MWCETT (Modified Weighted Cumulative Expected Transmission Time) implémentée par le protocole HWMP.The quality of service (QoS) remains a major challenge to improve the performance of the mesh networks based on IEEE 802.11s. It is in this context that the contributions are part of our thesis, which improves the routing and quality of service (QoS) in the WMN networks. In order to provide a solution to this challenge and to improve the quality of service of real-time traffic, we propose a new method based on the reservation of bandwidth, combined with the protocol HWMP (Hybrid Wireless Mesh Protocol). This new method is called BRWMN (Multi-hop Bandwidth Reservation in WMN) and defines a technical reservation of bandwidth and a new metric called WAM (Weighted Airtim Metric) for the HWMP protocol. MBRWMN aims to provide required bandwidth hop-by-hop for the real- time traffic and uses an admission control so as to carry this out. However, to reduce the end-to-end delay and increase the throughput, we propose a new metric based on the diversity of channels combined with the transmission delay of packets. This new routing metric named NMH (New Metric for HWMP protocol) is used by the HWMP protocol. The solution we propose aimes to provide a better route for calculating the value of the metric NMH implemented by the HWMP protocol. For the same purpose and to improve the mesh network performance, we propose the method ODCAM (On Demand Channel Assignment Method), which proposes a new mechanism for channel diversity based on a hybrid method of allocating channels. The metric MWCETT (Modified Weighted Cumulative Expected Transmission time) is implemented by the HWMP protocol. In order to decrease the time of end-to-end delay and increase the throughput, our method calculates the MWCETT metric value along the route between the source and the destination.VERSAILLES-BU Sciences et IUT (786462101) / SudocSudocFranceF

    Étude des performances des algorithmes de re routage dans les réseaux ATM

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    VERSAILLES-BU Sciences et IUT (786462101) / SudocSudocFranceF

    Rerouting algorithm for non real time traffic

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    International audienc

    Reactive and adaptive monitoring to secure aggregation in wireless sensor networks

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    Data aggregation is considered as one of the fundamental distributed data processing procedures for saving the energy and minimizing the medium access layer contention in wireless sensor networks. However, sensor networks are likely to be deployed in an untrusted environment, which make them vulnerable against several attacks. A compromised node may forge arbitrary aggregation value and mislead the base station into trusting a false reading. Secure in-network aggregation can detect such manipulation. But, as long as such subversive activity is, reliable aggregation result can not be obtained. In contrast, the collection of individual sensor node values is robust and solves the problem of availability, but in an inefficient way. Our work seeks to bridge this gap in secure data collection. We propose a framework that enhances availability with efficiency close to that of in-network aggregation avoiding over-reliance on sensors. To achieve this, we design a scheme that is built on one core concept: no trust is supposed in any sensor. Therefore, we design a two hierarchical levels of monitoring to ensure the integrity and the accuracy of aggregate result, only when necessary, i.e. only when malicious activities are detected. Relying on this new type of monitoring mechanism, the framework has the ability to recover from aggregator failure without neglecting energy efficiency, providing thus much higher availability than other security protocols
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