Browsing by Author "Ksentini, Adlen"

Now showing 1 - 3 of 3
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    Half-Symmetric Lens based localization algorithm for wireless sensor networks
    (IEEE, 2012-10-25) Lasla, Noureddine; Derhab, Abdelouahid; Ouadjaout, Abdelraouf; Bagaa, Miloud; Ksentini, Adlen; Badache, Nadjib
    The area-based localization algorithms use only the location information of some reference nodes, called anchors, to give the residence area of the remaining nodes. The current algorithms use triangle, ring or circle as a geometric shape to determine the sensors' residence area. Existing works suffer from two major problems: (1) in some cases, they might issue wrong decisions about nodes' presence inside a given area, or (2) they require high anchor density to achieve a low location estimation error. In this paper, we deal with the localization problem by introducing a new way to determine the sensors' residence area which shows a better accuracy than the existing algorithms. Our new localization algorithm, called HSL (Half Symmetric Lens based localization algorithm for WSN), is based on the geometric shape of half-symmetric lens. We also uses the Voronoi diagram in HSL to mitigate the problem of unlocalizable sensor nodes. Finally, we conduct extensive simulations to evaluate the performance of HSL. Simulation results show that HSL has better locatable ratio and location accuracy compared to representative state-of-the-art area-based algorithms.
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    Multi-Path Multi-Channel Data Aggregation Scheduling in Wireless Sensor Networks
    (Wireless Days, 2013-11-13) Bagaa, Miloud; Younis, Mohamed; Ksentini, Adlen; Badache, Nadjib
    In-network aggregation is employed to cut on re-dundancy and conserve the network resources. To meet the criticality and responsiveness goals, the aggregated data are to be disseminated to the base-station reliably while reducing the delivery latency. In this paper, a novel approach is proposed fo Reliable Multi-channel Scheduling for timely dissemination of Aggregated data (RMSA). RMSA strives to form an aggregation tree such that there are k disjoint paths from each node to the base-station and finds a collision free schedule for node transmissions so that the aggregated data reaches the base-station in minimal time. RMSA is a cross-layer scheme that intertwines the formation of the multi-path structure and the assignment of transmission slots to the individual node with the objective of increasing the simultaneity of transmissions and reducing the buffering delay. The availability of multiple radio channels is further exploited in order to prevent colliding transmissions and boost the overall network throughput. RMSA is validated through simulation and is shown to outperform previously published schemes.
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    User mobility-aware Virtual Network Function placement for Virtual 5G Network Infrastructure
    (IEEE, ) Taleb, Tarik; Bagaa, Miloud; Ksentini, Adlen
    Cloud offerings represent a promising solution for mobile network operators to cope with the surging mobile traffic. The concept of carrier cloud has therefore emerged as an important topic of inquiry. For a successful carrier cloud, algorithms for optimal placement of Virtual Network Functions (VNFs) on federated cloud are of crucial importance. In this paper, we introduce different VNF placement algorithms for carrier cloud with two main design goals: i) minimizing path between users and their respective data anchor gateways and ii) optimizing their sessions' mobility. The two design goals effectively represent two conflicting objectives, that we deal with considering the mobility features and service usage behavioral patterns of mobile users, in addition to the mobile operators' cost in terms of the total number of instantiated VNFs to build a Virtual Network Infrastructure (VNI). Different solutions are evaluated based on different metrics and encouraging results are obtained.