Browsing by Author "Ouadjaout, Abdelraouf"

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    Congestion Detection Strategies in Wireless sensor Networks: A Comparative Study with Testbed Experiments
    (CERIST, 2014-07-07) Kafi, Mohamed Amine; Djenouri, Djamel; Ben Othman, Jalel; Ouadjaout, Abdelraouf; Badache, Nadjib
    Event based applications of Wireless Sensor Networks (WSNs) are prone to tra c congestion, where unpredicted event detection yields simultaneous generation of tra c at spatially co-related nodes, and its propagation towards the sink. This results in loss of information and waste energy. Early congestion detection is thus of high importance in such WSN applications to avoid the propagation of such a problem and to reduce its consequences. Di erent detection metrics are used in the congestion control literature. However, a comparative study that investigates the di erent metrics in real sensor motes environment is missing. This paper focuses on this issue and compares some detection metrics in a testbed network with MICAz motes. Results show the e ectiveness of each method in di erent scenarios and concludes that the combination of bu er length and channel load constitute the better candidate for early and fictive detection.
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    Congestion Detection Strategies in Wireless Sensor Networks: A Comparative Study with Testbed Experiments
    (Elsevier, 2014) Kafi, Mohamed Amine; Djenouri, Djamel; Ben Othman, Jalel; Ouadjaout, Abdelraouf; Badache, Nadjib
    Event based applications of Wireless Sensor Networks (WSNs) are prone to traffic congestion, where unpredicted event detection yields simultaneous generation of traffic at spatially co-related nodes, and its propagation towards the sink. This results in loss of information and waste energy. Early congestion detection is thus of high importance in such WSN applications to avoid the propagation of such a problem and to reduce its consequences. Different detection metrics are used in the congestion control literature. However, a comparative study that investigates the different metrics in real sensor motes environment is missing. This paper focuses on this issue and compares some detection metrics in a testbed network with MICAz motes. Results show the effectiveness of each method in different scenarios and concludes that the combination of buffer length and channel load constitute the better candidate for early and fictive detection.
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    Congestion Detection Strategies in Wireless Sensor Networks: A Comparative Study with Testbed Experiments
    (Elsevier, 2014-09) Kafi, Mohamed Amine; Djenouri, Djamel; Ouadjaout, Abdelraouf; Badache, Nadjib
    Event based applications of Wireless Sensor Networks (WSNs) are prone to traffic congestion, where unpredicted event detection yields simultaneous generation of traffic at spatially co-related nodes, and its propagation towards the sink. This results in loss of information and waste energy. Early congestion detection is thus of high importance in such WSN applications to avoid the propagation of such a problem and to reduce its consequences. Different detection metrics are used in the congestion control literature. However, a comparative study that investigates the different metrics in real sensor motes environment is missing. This paper focuses on this issue and compares some detection metrics in a testbed network with MICAz motes. Results show the effectiveness of each method in different scenarios and concludes that the combination of buffer length and channel load constitute the better candidate for early and fictive detection.
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    DZ50: Energy-Efficient Wireless Sensor Mote Platform for Low Data Rate Applications
    (CERIST, 2014-07-07) Ouadjaout, Abdelraouf; Lasla, Noureddine; Bagaa, Miloud; Doudou, Messaoud; Zizoua, Cherif; Kafi, Mohamed Amine; Derhab, Abdelouahid; Djenouri, Djamel; Badache, Nadjib
    A low cost and energy efficient wireless sensor mote platform for low data rate monitoring applications is presented. The new platform, named DZ50, is based on the ATmega328P micro-controller and the RFM12b transceiver, which consume very low energy in low-power mode. Considerable energy saving can be achieved by reducing the power consumption during inactive (sleep) mode, notably in low data rate applications featured by long inactive periods. Without loss of generality, spot monitoring in a Smart Parking System (SPS) and soil moisture in a Precision Irrigation System (PIS) are selected as typical representative of low data rate applications. The performance of the new platform is investigated for typical scenarios of the selected applications and compared with that of MicaZ and TelosB. Energy measurement has been carried out for different network operation states and settings, where the results reveal that the proposed platform allows to multiply the battery lifetime up to 7 times compared to MicaZ and TelosB motes in 10s sampling period scenarios.
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    DZ50: Energy-efficient Wireless Sensor Mote Platform for Low Data Rate Applications
    (Elsevier, 2014) Ouadjaout, Abdelraouf; Lasla, Noureddine; Bagaa, Miloud; Doudou, Messaoud; Zizoua, Cherif; Kafi, Mohamed Amine; Derhab, Abdelouahid; Djenouri, Djamel; Badache, Nadjib
    A low cost and energy e_cient wireless sensor mote platform for low data rate monitoring applications is presented. The new platform, named DZ50, is based on the ATmega328P micro-controller and the RFM12b transceiver, which consume very low energy in low-power mode. Considerable energy saving can be achieved by reducing the power consumption during inactive (sleep) mode, notably in low data rate applications featured by long inactive periods. Without loss of generality, spot monitoring in a Smart Parking System (SPS) and soil moisture in a Precision Irrigation System (PIS) are selected as typical representative of low data rate applications. The performance of the new platform is investigated for typical scenarios of the selected applications and compared with that of MicaZ and TelosB. Energy measurements have been carried out for di_erent network operation states and settings, where the results reveal that the proposed platform allows to multiply the battery lifetime up to 7 times compared to MicaZ and TelosB motes in 10s sampling period scenarios.
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    Efficient data aggregation with in-network integrity control for WSN
    (Elsevier, 2012-10) Bagaa, Miloud; Challal, Yacine; Ouadjaout, Abdelraouf; Lasla, Noureddine; Badache, Nadjib
    Energy is a scarce resource in Wireless Sensor Networks (WSN). Some studies show that more than 70% of energy is consumed in data transmission in WSN. Since most of the time, the sensed information is redundant due to geographically collocated sensors, most of this energy can be saved through data aggregation. Furthermore, data aggregation improves bandwidth usage and reduces collisions due to interference. Unfortunately, while aggregation eliminates redundancy, it makes data integrity verification more complicated since the received data is unique. In this paper, we present a new protocol that provides control integrity for aggregation in wireless sensor networks. Our protocol is based on a two-hop verification mechanism of data integrity. Our solution is essentially different from existing solutions in that it does not require referring to the base station for verifying and detecting faulty aggregated readings, thus providing a totally distributed scheme to guarantee data integrity. We carried out numerical analysis and simulations using the TinyOS environment. Results show that the proposed protocol yields significant savings in energy consumption while preserving data integrity, and outperforms comparable solutions with respect to some important performance criteria.
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    Efficient Multi-Path Data Aggregation Scheduling in Wireless Sensor Networks
    (CERIST, 2013) Bagaa, Miloud; Badache, Nadjib; Ouadjaout, Abdelraouf; Younis, Mohamed
    In wireless sensor networks, in-network data aggregation filters out redundant sensor readings in order to reduce the energy and bandwidth consumed in disseminating the data to the base-station. In this paper, we investigate the problem of reliable collection of aggregated data with minimal latency. The aim is to form an aggregation tree such that there are k disjoint paths from each node to the basestation and find a collision-free schedule for node transmissions so that the aggregated data reaches the base-station in minimal time. We propose a novel algorithm for Reliable and Timely dissemination of Aggregated Data (RTAD). RTAD intertwines the formation of the aggregation tree and the allocation of time slots to nodes, and assigns parents to the individual nodes in order to maximize time slot reuse. The simulation results show that RTAD outperforms competing algorithms in the literature.
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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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    Information Security in Wireless Sensor Networks
    (World Scientific, 2009-10) Ouadjaout, Abdelraouf; Bagaa, Miloud; Bachir, Abdelmalik; Challal, Yacine; Lasla, Noureddine; Khelladi, Lyes
    In 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.
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    Interference-aware Congestion Control Protocol for Wireless Sensor Networks
    (Elsevier, 2014-09) Kafi, Mohamed Amine; Djenouri, Djamel; Ben Othman, Jalel; Ouadjaout, Abdelraouf; Bagaa, Miloud; Lasla, Noureddine; Badache, Nadjib
    This paper deals with congestion and interference control in wireless sensor networks (WSN), which is essential for improving the throughput and saving the scarce energy in networks where nodes have different capacities and traffic patterns. A scheme called IACC (Interference-Aware Congestion Control) is proposed. It allows maximizing link capacity utilization for each node by controlling congestion and interference. This is achieved through fair maximum rate control of interfering nodes in inter and intra paths of hot spots. The proposed protocol has been evaluated by simulation, where the results rival the effectiveness of our scheme in terms of energy saving and throughput. In particular, the results demonstrate the protocol scalability and considerable reduction of packet loss that allow to achieve as high packet delivery ratio as 80% for large networks.
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    Interference-Aware Congestion Control Protocol for Wireless Sensor Networks
    (CERIST, 2014-07-07) Kafi, Mohamed Amine; Djenouri, Djamel; Ben Othman, Jalel; Ouadjaout, Abdelraouf; Bagaa, Miloud; Lasla, Noureddine; Badache, Nadjib
    This paper deals with congestion and interference control in wireless sensor networks (WSN), which is essential for improving the throughput and saving the scarce energy in networks where nodes have di erent capacities and tra c patterns. A scheme called IACC (Interference-Aware Congestion Control ) is proposed. It allows maximizing link capacity utilization for each node by controlling congestion and interference. This is achieved through fair maximum rate control of interfering nodes in inter and intra paths of hot spots. The proposed protocol has been evaluated by simulation, where the results rival the e ectiveness of our scheme in terms of energy saving and throughput. In particular, the results demonstrate the protocol scalability and considerable reduction of packet loss that allows to achieve as high packet delivery ratio as 80% for large networks.
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    On optimal anchor placement for effecient area-based localization in wireless networks
    (IEEE, 2015-06-08) Lasla, Noureddine; Younis, Mohamed; Ouadjaout, Abdelraouf; Badache, Nadjib
    Area-based localization is a simple and efficient approach, where each node estimates its position based on proxim- ity information to some special nodes with known location, called anchors. Based on the anchors’ coordinates, each node first determines its residence area and then approximates its position as the centroid of that area. Therefore, the accu- racy of the estimated position depends on the size of the residence area; the smaller the residence area is, the bet- ter the accuracy is likely to be. Because the size of the residence area mainly depends on the number and the posi- tions of anchor nodes, their deployment should be carefully considered in order to achieve a better accuracy while mini- mizing the cost. For this purpose, in this paper we conduct a theoretical study on anchor placement for a very popular area based localization approach. We determine the optimal anchor placement pattern for increased accuracy and how to achieve a particular accuracy goal with the least anchor count. Our analytical results are further validated through simulation.
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    On optimal anchor placement for effecient area-based localization in wireless networks
    (CERIST, 2015-06-08) Lasla, Noureddine; Younis, Mohamed; Ouadjaout, Abdelraouf; Badache, Nadjib
    Area-based localization is a simple and efficient approach, where each node estimates its position based on proxim- ity information to some special nodes with known location, called anchors. Based on the anchors’ coordinates, each node first determines its residence area and then approximates its position as the centroid of that area. Therefore, the accu- racy of the estimated position depends on the size of the residence area; the smaller the residence area is, the bet- ter the accuracy is likely to be. Because the size of the residence area mainly depends on the number and the posi- tions of anchor nodes, their deployment should be carefully considered in order to achieve a better accuracy while mini- mizing the cost. For this purpose, in this paper we conduct a theoretical study on anchor placement for a very popular area based localization approach. We determine the optimal anchor placement pattern for increased accuracy and how to achieve a particular accuracy goal with the least anchor count. Our analytical results are further validated through simulation.
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    On the Effect of Sensing-Holes in PIR-based Occupancy Detection Systems
    (2016-02-20) Ouadjaout, Abdelraouf; Lasla, Noureddine; Djenouri, Djamel; Zizoua, Cherif
    Sensing-holes in PIR-based motion detection systems are considered, and their impact on occupancy monitoring applications is investigated. To our knowledge, none of prior works on PIR-based systems consider the presence of these holes, which represents the major cause for low precision of such systems in environments featured with very low mobility of occupants, such as working offices. We consider optimal placement of PIRs that ensures maximum coverage in presence of holes. The problem is formulated as a mixed integer linear programming optimization problem (MILP). Based on this formulation, an experimental study on a typical working office has been carried out. The empirical results quantify the effects of the holes on the detection accuracy and demonstrate the enhancement provided by the optimal deployment of the solution.
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    Point In half symmetric LEns : A new range-free localization protocol for wireless sensor networks
    (CERIST, 2011-02) Lasla, Noureddine; Derhab, Abdelouahid; Ouadjaout, Abdelraouf; Bagaa, Miloud; Badache, Nadjib
    As location information is used by many sensor network applications, localization is considered a keystone in their design. Existing localization protocols can be classi ed as range-based or range-free approaches. Range- based approaches are costly as they require embedding each sensor node with an additional hardware to estimate inter-node distances. In contrast, the range-free approaches are cheaper, and they estimate node position by collecting information from some special nodes with known location called anchors. Thus, compared with range- based approaches, the range-free ones are more suitable for WSNs. In this paper, we propose PIV (Point In half Vesica-piscis), a new distributed range-free localization protocol for wireless sensor networks. PIV is designed based on the geometric concept of Vesica-piscis, which helps to relax some unrealistic assumptions and incur the lower cost. Complexity analysis and simulations results show that PIV has the lowest message cost among the existing localization schemes and o ers the best trade-o between location accuracy and ratio of localized nodes.
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    Poster Abstract: Static Analysis of Device Drivers in TinyOS
    (ACM/IEEE, 2014-04-15) Ouadjaout, Abdelraouf; Lasla, Noureddine; Bagaa, Miloud; Badache, Nadjib
    In this paper, we present SADA, a static analysis tool to verify device drivers for TinyOS applications. Its broad goal is to certify that the execution paths of the application complies with a given hardware specification. SADA can handle a broad spectrum of hardware specifications, ranging from simple assertions about the values of configuration registers, to complex behaviors of possibly several connected hardware components. The hardware specification is expressed in BIP, a language for describing easily complex interacting discrete components. The analysis of the joint behavior of the application and the hardware specification is then performed using the theory of Abstract Interpretation. We have done a set of experiments on some TinyOS applications. Encouraging results are obtained that confirm the effectiveness of our approach.
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    REFIACC: Reliable, Efficient, Fair and Interference-Aware Congestion Control Protocol for Wireless Sensor Networks
    (Elsevier, 2016-05-28) Kafi, Mohamed Amine; Ben Othman, Jalel; Ouadjaout, Abdelraouf; Bagaa, Miloud; Badache, Nadjib
    The recent wireless sensor network applications are resource greedy in terms of throughput and network reliability. However, the wireless shared medium leads to links interferences in addition to wireless losses due to the harsh environment. The effect of these two points translates on differences in links bandwidth capacities, lack of reliability and throughput degradation. In this study, we tackle the problem of throughput maximization by proposing an efficient congestion control-based schedule algorithm, dubbed REFIACC (Reliable, Efficient, Fair and Interference-Aware Congestion Control) protocol. REFIACC prevents the interferences and ensures a high fairness of bandwidth utilization among sensor nodes by scheduling the communications. The congestion and the interference in inter and intra paths hot spots are mitigated through tacking into account the dissimilarity between links' capacities at the scheduling process. Linear programming is used to reach optimum utilization efficiency of the maximum available bandwidth. REFIACC has been evaluated by simulation and compared with two pertinent works. The results show that the proposed solution outperforms the others in terms of throughput and reception ratio (more than 80%) and can scale for large networks.
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    REFIACC: Reliable, efficient, fair and interference-aware congestion control protocol for wireless sensor networks
    (Elsevier, 2017) Kafi, Mohamed Amine; Ben-Othman, Jalel; Ouadjaout, Abdelraouf; Bagaa, Miloud
    The recent wireless sensor network applications are resource greedy in terms of throughput and net- work reliability. However, the wireless shared medium leads to links interferences in addition to wireless losses due to the harsh environment. The effect of these two points translates on differences in links bandwidth capacities, lack of reliability and throughput degradation. In this study, we tackle the prob- lem of throughput maximization by proposing an efficient congestion control-based schedule algorithm, dubbed REFIACC (Reliable, Efficient, Fair and Interference-Aware Congestion Control) protocol. REFIACC prevents the interferences and ensures a high fairness of bandwidth utilization among sensor nodes by scheduling the communications. The congestion and the interference in inter and intra paths hot spots are mitigated through tacking into account the dissimilarity between links’ capacities at the scheduling process. Linear programming is used to reach optimum utilization efficiency of the maximum available bandwidth. REFIACC has been evaluated by simulation and compared with two pertinent works. The re- sults show that the proposed solution outperforms the others in terms of throughput and reception ratio (more than 80%) and can scale for large networks.
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    Secure and efficient disjoint multipath construction for fault tolerant routing in wireless sensor networks
    (Elsevier, 2011-07) Challal, Yacine; Ouadjaout, Abdelraouf; Lasla, Noureddine; Bagaa, Miloud; Abdelkarim, Hadjidj
    In wireless sensor networks, reliability is a design goal of a primary concern. To build a comprehensive reliable system, it is essential to consider node failures and intruder attacks as unavoidable phenomena. In this paper, we present a new intrusion-fault tolerant routing scheme offering a high level of reliability through a secure multipath routing construction. Unlike existing intrusion-fault tolerant solutions, our protocol is based on a distributed and in-network verification scheme, which does not require any referring to the base station. Furthermore, it employs a new multipath selection scheme seeking to enhance the tolerance of the network and conserve the energy of sensors. Extensive analysis and simulations using TinyOS showed that our approach improves many important performance metrics such as: the mean time to failure of the network, detection overhead of some security attacks, energy consumption, and resilience.
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    SEDAN: Secure and Efficient protocol for Data Aggregation in wireless sensor Networks
    (IEEE, 2007-10-15) Bagaa, Miloud; Lasla, Noureddine; Ouadjaout, Abdelraouf; Challal, Yacine
    —Energy is a scarce resource in Wireless Sensor Networks. Some studies show that more than 70% of energy is consumed in data transmission. Since most of the time, the sensed information is redundant due to geographically collocated sensors, most of this energy can be saved through data aggregation. Furthermore, data aggregation improves bandwidth usage. Unfortunately, while aggregation eliminates redundancy, it makes data integrity verification more complicated since the received data is unique. In this paper, we present a new protocol that provides secure aggregation for wireless sensor networks. Our protocol is based on a two hops verification mechanism of data integrity. Our solution is essentially different from existing solutions in that it does not require referring to the base station for verifying and detecting faulty aggregated readings, thus providing a totally distributed scheme to guarantee data integrity. We carried out simulations using TinyOS environment. Simulation results show that the proposed protocol yields significant savings in energy consumption while preserving data integrity.