Abderrezak Rachedi

A survey on mobility management protocols in Wireless Sensor Networks based on 6LoWPAN technology

Mobility has the advantage of enlarging the WSN applications of the Internet of Things. However, proposing a mobility support protocol in Wireless Sensor Networks (WSNs) represents a significant challenge. In this paper, we proposed a survey on mobility management protocols in WSNs based on 6LoWPAN technology. This technology enables to connect IP sensor devices to other IP networks without any need for gateways. We highlighted the advantages and drawbacks with performances issues of each studied solution. Then, in order to select a typical classification of mobility management protocols in WSNs, we provided some classification criteria and approaches on which these protocols are based. Finally, we presented a comparative study of the existing protocols in terms of the required performances for this network type.

A distributed advanced analytical trust model for VANETs

In this paper we propose a trust model based on a Markov chain in order to formalize the trust metric variation and its stability in the context of Vehicular Ad hoc Networks (VANETs). The proposed model takes into account not only the dynamic trust metric variation according to the vehicles behaviors, but also the constraints related to the monitoring process. In our model each vehicle can act as monitor and update the trust metric of its neighbors according to their behavior in the network. In addition, our model can be customized through different parameters like the trust interval and the number of transitions needed to reach the highest trust level. This flexibility enables to adapt the model according to the application context. The performance evaluation of the proposed model is presented with different parameters and two types of disruptive vehicles are taken into account: malicious and selfish. The obtained results show the resistance, the robustness and the incentive of the proposed model against the fluctuations of the vehicles behaviors.

Cognitive-Radio-Based Internet of Things: Applications, Architectures, Spectrum Related Functionalities, and Future Research Directions

Recent research and technology trends are shifting toward IoT and CRNs. However, we think that the things-oriented, Internet-oriented, and semantic-oriented versions of IoT are meaningless if IoT objects are not equipped with cognitive radio capability. Equipping IoT objects with CR capability has lead to a new research dimension of CR-based IoT. In this article, we present an overview of CR-based IoT systems. We highlight potential applications of CR-based IoT systems. We survey architectures and frameworks of CR-based IoT systems. We furthermore discuss spectrum-related functionalities for CR-based IoT systems. Finally, we present open issues, research challenges, and future direction for these CR-based IoT networks.

Trust and Mobility-based Clustering Algorithm for Secure Mobile Ad Hoc Networks

An Mobile Ad-hoc network (MANET) is formed when group of mobile wireless nodes collaborate between them to communicate through wireless links in the absence of the fixed infrastructure and any centralized control. Theses characteristics make it able to adapt and operate in difficult conditions, but also vulnerable to new security attacks not present in a traditional wired network. In this paper a new approach to secure MANETs has been proposed. Our solution is based on our efficient trust model and distributed algorithm to clustering network in order to distribute role of certification authority (CA) in each cluster. We use fully self-organized security and monitoring process to supervise behaviors of nodes with low trust level. Also, we propose clustering algorithm based on the trust and mobility metric to select CA and to establish public key infrastructure (PKI) in each cluster. Furthermore, we introduce new concept Dynamic Demilitarized Zone (DDMZ) to protect CAs and avoid the single point of failure in each cluster. The DDMZ is formed by set of the dispensable nodes which must be confident and located at one-hop from the CA. Our approach can be easily extended to other hierarchical routing protocols. The simulation results include an evaluation of the stability, availability and security.

Energy-aware object tracking algorithm using heterogeneous wireless sensor networks

Mobile target tracking consists in detecting and locating targets in a surveillance region. Wireless Multimedia Sensor Networks (WMSN) can provide more information about the moving target than classical Wireless Sensor Networks (WSN), but their process and the transmission of multimedia data are costly which reduces the networks lifetime. In this paper, we propose a low-cost new solution for tracking a mobile target called EAOT (Energy Aware Object Tracking). It consists of a distributed cooperative algorithm that runs in heterogeneous Wireless Sensor Networks composed of both scalar and multimedia sensors. The scalar sensors (MS) are equipped with a motion detector; their role is to detect the target and then activate the camera sensors (CS) through message exchanges. We conducted simulations to evaluate the performance of the proposed mechanism in terms of tracking accuracy, number of exchanged messages, energy consumption, and spatial average deviation. The results are compared to two existing solutions: one based on simple camera sensors which always run in active mode and the other one based on the optimal camera node selection (OCNS) to track the target. The obtained results show that for the same number of nodes, EAOT consumes between 2.6% and 44% less energy than OCNS depending on the distribution of MS/CS.

Incentive Scheduler Algorithm for Cooperation and Coverage Extension in Wireless Networks

In this paper, we focus on wireless coverage extension and nodes cooperation. We propose a new protocol based on an incentive approach and a scheduling algorithm to reward cooperative nodes. The cost of cooperation can be prohibitively expensive in terms of quality of service (QoS) and energy consumption, which does not motivate some nodes to cooperate. Therefore, we introduce a percentage of cooperation and QoS parameters in the scheduling algorithm called coverage extension based on incentive scheduling to incite potential mobile relaying nodes to cooperate and, in turn, extend the wireless areas. We use the cross-layer approach to optimize the QoS parameters. The proposed solution not only incites the nodes to cooperate but enhances the QoS by increasing the average throughput and decreasing the delay as well. The simulation results show that the proposed solution not only gives better results than the well-known scheduling algorithms, such as maximum signal-to-noise ratio (MaxSNR) and weighted fair opportunistic (WFO), but allows the cooperative mobile nodes to increase their own throughput by around 114% as well. The total amount of data transmitted out of the cell to extend the coverage can be increased by around 59% compared with the scheduling algorithm MaxSNR.

Toward a cross-layer monitoring process for mobile ad hoc networks

The intrusion detection system (IDS) for mobile ad hoc networks (MANET) consists in monitoring the nodes behavior, in order to detect the malicious activity of nodes. Many existing solutions deal with the problem at each layer separately. But new kinds of misbehavior attacks are cross-layer attacks. And such smart misbehaviors cannot be detected at the level of one layer. In this paper, we propose a new cross-layer approach based on physical, MAC, and routing layers for a monitoring mechanism. A new analytical model is proposed to illustrate the parameters effect on these different layers. The impact of the signal to noise ratio (SNR) and the distance between monitor and monitored nodes are clearly introduced. Moreover, the difference between the carrier sense, the interference range, and the transmission range is taken into account in our model. The proposed model improves the evaluation of the nodes cooperation and reduces the risk of having any false positive rate. The analytical study and simulation results illustrate our purpose. In addition, with the simulations results, we illustrate the impact of the distance between monitor and monitored nodes on the monitoring mechanism. Finally, we show that our cross-layer mechanism has a lower false positive rate than the classical Watchdog mechanism in different networks parameters such as the nodes density, the speed mobility, and the different traffic loads.

When Cognitive Radio meets the Internet of Things

Internet of Things (IoT) is a world wide network of interconnected objects. IoT capable objects will be interconnected through wired and wireless communication technologies. However, cost-effectiveness issues and accessibility to remote users make wireless communication as a feasible solution. A majority of possibilities have been proposed but many of these suffer from vulnerabilities to dynamic environmental conditions, ease of access, bandwidth allocation and utilization, and cost to purchase spectrum. Thus trends are shifting to the adaptability of Cognitive Radio Networks (CRNs) into IoT. Additionally, ubiquitous objects with cognitive capabilities will be able to make intelligent decisions to achieve interference-free and on-demand services. The main goal of this paper is to discuss how CR technology can be helpful for the IoT paradigm. More precisely, in this paper, we highlight CR functionalities, specially spectrum sensing in conjunction with cloud services to serve as self-reconfigurable IoT solutions for a number of applications.

IEEE Access Special Section Editorial Smart Grids: a Hub of Interdisciplinary Research

The smart grid is an important hub of interdisciplinary research where researchers from different areas of science and technology combine their efforts to enhance the traditional electrical power grid. Due to these efforts, the traditional electrical grid is now evolving. The envisioned smart grid will bring social, environmental, ethical, legal and economic benefits. Smart grid systems increasingly involve machine-to-machine communication as well as human-to-human, or simple information retrieval. Thus, the dimensionality of the system is massive. The smart grid is the combination of different technologies, including control system theory, communication networks, pervasive computing, embedded sensing devices, electric vehicles, smart cities, renewable energy sources, Internet of Things, wireless sensor networks, cyber physical systems, and green communication. Due to these diverse activities and significant attention from researchers, education activities in the smart grid area are also growing.

A Secure Architecture for Mobile Ad Hoc Networks

In this paper, we propose a new architecture based on an efficient trust model and clustering algorithm in order to distribute a certification authority (CA) for ensuring the distribution of certificates in each cluster. We use the combination of fully self-organized security for trust model like PGP adapted to ad-hoc technology and the clustering algorithm which is based on the use of trust and mobility metric, in order to select the clusterhead and to establish PKI in each cluster for authentication and exchange of data. Furthermore, we present new approach Dynamic Demilitarized Zone (DDMZ) to protect CA in each cluster. The principle idea of DDMZ consists to select the dispensable nodes, also called registration authorities; these nodes must be confident and located at one-hope from the CA. Their roles are to receive, filter and treat the requests from any unknown node to CA. With this approach, we can avoid the single point of failure in each cluster. This architecture can be easily extended to other hierarchical routing protocols. Simulation results confirm that our architecture is scalable and secure.