Browsing by Author "Khelladi, Lyes"
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- ItemEfficient On-Demand Multi-Node Charging Techniques for Wireless Sensor Networks(Elsevier, 2016-10-01) Khelladi, Lyes; Djenouri, Djamel; Rossi, Michele; Badache, NadjibThis paper deals with wireless charging in sensor networks and explores efficient policies to perform simultaneous multi-node power transfer through a mobile charger (MC).The proposed solution, called On-demand Multi-node Charging (OMC), features an original threshold-based tour launching (TTL) strategy, using request grouping, and a path planning algorithm based on minimizing the number of stopping points in the charging tour. Contrary to existing solutions, which focus on shortening the charging delays, OMC groups incoming charging requests and optimizes the charging tour and the mobile charger energy consumption. Although slightly increasing the waiting time before nodes are charged, this allows taking advantage of multiple simultaneous charges and also reduces node failures. At the tour planning level, a new modeling approach is used. It leverages simultaneous energy transfer to multiple nodes by maximizing the number of sensors that are charged at each stop. Given its NP-hardness, tour planning is approximated through a clique partitioning problem, which is solved using a lightweight heuristic approach. The proposed schemes are evaluated in offline and on-demand scenarios and compared against relevant state-of-the-art protocols. The results in the offline scenario show that the path planning strategy reduces the number of stops and the energy consumed by the mobile charger, compared to existing offline solutions. This is with further reduction in time complexity, due to the simple heuristics that are used. The results in the on-demand scenario confirm the effectiveness of the path planning strategy. More importantly, they show the impact of path planning, TTL and multi-node charging on the efficiency of handling the requests, in a way that reduces node failures and the mobile charger energy expenditure.
- ItemInformation Security in Wireless Sensor Networks(World Scientific, 2009-10) Ouadjaout, Abdelraouf; Bagaa, Miloud; Bachir, Abdelmalik; Challal, Yacine; Lasla, Noureddine; Khelladi, LyesIn this chapter, we provide a comprehensive survey of security issues in wireless sensor networks. We show that the main features of WSNs, namely their limited resources, wireless communications, and close physical coupling with environment, are the main causes of the their security vulnerabilities. We discuss the main attacks stemming from these vulnerabilities, along with the solutions proposed in the literature to cope with them. The security solutions are analyzed with respect to the different layers of the network protocol stack and cover the following issues: Key management, secure data dissemination, secure data aggregation, secure channel access and secure node compromise.
- ItemMSR : Minimum-Stop Recharging Scheme for Wireless Rechargeable Sensor Networks(CERIST, 2014-07-02) Khelladi, Lyes; Djenouri, Djamel; Badache, Nadjib; Bouabdallah, Abdelmadjid; Lasla, NoureddineThis paper deals with simultaneous energy transfer to multiple nodes for scalable wireless recharging in wireless sensor networks. All existing recharging schemes rely on the use of a mobile charger that roves the network and drops by some locations for nodes recharging. However, they focus on the efficiency of energy transfer and neglect the energy engendered by the charger movement. This is tackled in this paper, where the wireless charging is modeled as a path optimization problem for the mobile charger, with objective function to minimizing the number of stop locations in the path. Due to the NP-harness of the problem, we propose a simple but efficient heuristic. It is based on clique partitioning to find the minimum number of locations allowing the mobile charger to replenish all the node’s batteries in the network. Evaluation results demonstrate that the proposed approach significantly reduces the total energy consumption of the mobile charger, while using a low-complexity techniques that permit scalability to a higher number of nodes.
- ItemRevisiting Directed Diffusion In The Era Of IoT-WSNs : Power Control For Adaptation to High Density(IEEE Xplore, 2017-08-28) Khelladi, LyesWireless Sensor Networks (WSNs) have been recognized as a crucial and enabling technology in the world of Internet of Things (IoT). However, their integration with IoT arises new design challenges, compared to conventional WSNs applications. This paper addresses the challenge of high node density and its impact on the design of IoT-WSNs routing protocols. We propose a power-aware topology control mechanism built upon the prominent routing scheme, Directed Diffusion. Moreover, we take benefit from the power-awareness feature of the topology control mechanism in order to compute an energy consumption metric, allowing the selection of energy-efficient routes. The simulation results demonstrate an improvement by the proposed protocol in terms of energy efficiency, data reporting delays and delivery success rate.
- ItemScalability of Wireless MAC Protocols in Mobile Ad hoc Networks(IEEE, 2005-07) Djenouri, Djamel; Bouznada, Mohamed; Khiyat, Faten; Khelladi, LyesThe rapid proliferation of lightweight wireless mobile devices, such as laptops, PDAs, and sensors makes mobile ad hoc networks (MANETs) an exciting and important research area nowadays. The MANET community have been concentrating on some problems related to the network layer, especially on the routing protocols. But regarding the MAC layer, little has been done. Our contri- bution in this paper is the deep investigation of the MAC protocols scalability in MANETs, using the GloMoSim simulation tool. We think we are the first who consider the scalability factor when analyzing MAC protocols in MANETs.
- ItemSecurity Issues of Mobile Ad hoc and Sensor Networks(IEEE Communications Society, 2005-12) Djenouri, Djamel; Khelladi, Lyes; Badache, NadjibSecurity in mobile ad hoc networks is difficult to achieve, notably because of the vulnerability of wireless links, the limited physical protection of nodes, the dynamically changing topology, the absence of a certification authority, and the lack of a centralized monitoring or management point. Earlier studies on mobile ad hoc networks (MANETs) aimed at proposing protocols for some fundamental problems, such as routing, and tried to cope with the challenges imposed by the new environment. These protocols, however, fully trust all nodes and do not consider the security aspect. They are consequently vulnerable to attacks and misbehavior. More recent studies focused on security problems in MANETs, and proposed mechanisms to secure protocols and applications. This article surveys these studies. It presents and discusses several security problems along with the currently proposed solutions (as of July 2005) at different network layers of MANETs. Security issues involved in this article include routing and data forwarding, medium access, key management and intrusion detection systems (IDSs). This survey also includes an overview of security in a particular type of MANET, namely, wireless sensor networks (WSNs).
- ItemLe Service de routage dans les réseaux de capteurs(Université des Sciences et de la Technologie Houari-Boumediene (USTHB) : Faculté d'éléctronique et d'informatique, 2005) Khelladi, Lyes; Badache, NadjibLes avancées récentes dans le domaine de la communication sans fil et les technologies «MEMS» (Micro-electro-mechanical systems) ont permis le développement de microcomposants qui intègrent des dispositifs de captages et de communication sans fil dans un seul circuit, à dimension réduite, et avec un coût raisonnable. Ces composants, communément appelés micro-capteurs, ont favorisé l’idée de développer les réseaux de capteurs basés sur la collaboration d’un grand nombre de noeuds opérant d’une façon autonome, et communiquant entre eux via des transmissions à courte portée. Différents des réseaux ad hoc traditionnels, les réseaux de capteurs exigent de nouvelles limitations pour la conception des protocoles de communication. Par exemple, les protocoles de routage doivent, en plus de leurs fonctions classiques, participer à la synthèse et l’agrégation des données retournées aux utilisateurs, tout en assurant un fonctionnement optimal en consommation d'énergie, car chaque noeud est alimenté par une ressource d’énergie limitée et généralement irremplaçable.. Dans ce travail, nous présentons une étude détaillée sur la problématique de routage dans les réseaux de capteurs. Pour cela, un état de l’art est tout d'abord effectué, afin de recenser la plupart des protocoles de routage ayant été spécifiquement conçus pour les réseaux de capteurs. Cet état de l'art fournit une classification des protocoles développés en quatre catégories, en plus d'une discussion décrivant les avantages et les inconvénients de chacun d'eux. Par la suite, une étude basée sur des résultats de simulation vient mettre en évidence la dégradation des performances du protocole de routage Directed Diffusion dans les réseaux denses. Basé sur les résultats de cette étude, des améliorations à ce protocole ont été proposées, elle consistent essentiellement à : 1- Utiliser la technique des réseaux à consommation d’énergie minimale (MECN) comme étape d’initialisation dans le protocole Directed Diffusion, afin de réduire le degré de connectivité de la topologie de communication considérée. 2- Définir et utiliser une métrique de coût énergétique, pour permettre le choix de la route la plus efficace en consommation d’énergie.