Saadi Boudjit

Geocast Routing Protocols for VANETs: Survey and Guidelines

In Vehicular Ad Hoc Networks VANETs, a multitude of applications need to address not a single vehicle on the road, nor the whole totality of vehicles, but only a community of vehicles which share the same geographic location for the purpose of safety, traffic efficiency, advertising or infotainment. The goal is to transmit data from a unique source node to a set of destination nodes satisfying a set of geographic criteria. Geocast routing protocol in VANETs appear to be the most appropriate routing technique for these applications. In this investigation, we introduce some existing Geocast routing protocols for VANETs and then we provide a classification of these protocols based on the used relay selection technique. We present a comparison of these Geocast routing protocols according to different criteria and finally, we highlight some directions we are considering for our Geocast routing solution for VANETs.

Dynamic sink location update scope control mechanism for mobile sink Wireless Sensor Networks

Several recent works propose mobile sink based data gathering approaches to distribute energy consumption in Wireless Sensor Networks. However, mobility based algorithms require the sink to periodically update its location to the network to ensure multi-hop connectivity. This additional information increases the control traffic overhead, and thus energy consumption also increases. In this paper, we propose a distributive energy efficient sink location update mechanism for mobile sink WSNs, along with a preemptive buffering data collection technique. This sink location update mechanism combines MPR based broadcast [2] algorithm with a distributed local repair mechanism, whereby, sensor nodes dynamically control the scope of sink location update messages. In preemptive buffering mechanism, sinks neighbor nodes act as temporary data collection points, referred as roots, to prevent data loss when sink moves out of their vicinity. We show by simulations that our proposal effectively reduces the energy consumption and data losses of the network.

New priority MAC protocol for wireless body area networks

The rapid advancements in wireless communication technologies and micro-electronics systems have fostered the development of small and intelligent micro-components that incorporate sensing devices and wireless communications into a single miniature circuit that are wearable or implementable inside the human body for the purpose of medical and healthcare applications. These components when deployed are mainly known as WBANs for Wireless Body Area Networks. One of the main issues in such networks is the medium access techniques mainly for those data which could be urgent. The design of a medium access control protocol for a WBAN is a challenge due to the characteristics of wireless channel, the diversity of traffic, access latency and the need for minimization of energy consumption. Based on the integrated super frame structure of IEEE 802.15.4 and IEEE 802.15.6, an hybrid medium access control protocol named Priority MAC (PMAC) is proposed in this paper. In PMAC protocol, data channels are separated from control channels and the priority is given to the life critical traffic (emergency traffic). Furthermore, a sleep mode is used in order to save energy of the wearable wireless sensors and hence increase their lifetime.

AGDH (Asymmetric Group Diffie Hellman) An Efficient and Dynamic Group Key Ageement Protocol for Ad Hoc Networks

Confidentiality, integrity and authentication are more relevant issues in Ad hoc networks than in wired fixed networks. One way to address these issues is the use of symmetric key cryptography, relying on a secret key shared by all members of the network. But establishing and maintaining such a key (also called the session key) is a nontrivial problem. We show that Group Key Agreement (GKA) protocols are suitable for establishing and maintaining such a session key in these dynamic networks. We take an existing GKA protocol, which is robust to connectivity losses, and discuss all the issues for the correct functioning of this protocol in Ad hoc networks. We give implementation details and network parameters, which significantly reduce the computational burden of using public key cryptography in such networks

Multi-sensors' data gathering management system for a wireless health monitoring platform

Recent Advances in technology has led to the development of small, intelligent, wearable sensors capable of remotely performing critical health monitoring tasks and then transmitting patients data back to health care centers over wireless medium. In this paper, we propose in first step to study the issues related to the acquisition of medical information concerning a patient via a set of wireless sensors embedded in the patient himself. Secondly, we focus on treatment and use of this information either by a local contractor equipment (personal coordinator) with a capacity of calculation or offset after transfer in 3G and/or WiFi connection to a data server based at the attending physician or hospital.

A priority based cross layer data dissemination protocol for healthcare applications

This paper presents an effective cross layer data dissemination approach for healthcare Wireless Body Area Networks (WBANs). This approach guarantees an efficient medium access and route establishment while taking into account the traffic types, energy saving and scheduling issues. Simulation results prove the efficiency of our proposed approach in terms of energy consumption compared to IEEE 802.15.4 and IEEE 802.15.6 standards.

QoS architecture over WBANs for remote vital signs monitoring applications

Nowadays, the deployment of wireless sensors on patients becomes more and more popular. This promotes researchers and application developers to focus on issues related to Wireless Body Area Networks (WBANs). Applications associated to WBANs include healthcare, personal assistance, and entertainment where sensor nodes collect information and issue them to a central data server. To meet the new requirements of WBANs, the design of an efficient MAC protocol to handle the diversity of data traffic becomes necessary. In this paper, a Priority MAC (PMAC) protocol is introduced where priority is given to life critical traffics. A QoS architecture containing PMAC protocol is proposed and implemented. Simulation results show that our proposed architecture overcomes other architectures based on IEEE 802.15.4 and IEEE 802.15.6 in terms of energy consumption and Packet Delivery Ratio (PDR).

Hybrid heuristic for Capacitated Network Design Problem

This paper deals with the NP-hard Capacitated Network Design Problem (CNDP) with modular link capacity structure. We aim to optimize the underlying network, the allocation facilities and the transportation costs. It is assumed that for connecting two nodes, a fixed construction link cost is occurred or a specific unit transportation cost. There are several types of module facilities to allocate on links. In this paper, we propose a general model that combines design, allocation and routing problems. An hybrid approach is proposed which uses a greedy constructive and an iterative local search heuristics. Our proposition is tested on the Survivable fixed telecommunication Network Design Library (SNDlib) and a comparison of its performances against the best solution available in the literature is done. Computational tests show that our proposition is very efficient.

Distributed interference management in medical wireless sensor networks

Wireless communications are confronted to different kinds of interferences. Such interference has significant impact on the reliability of packet transmissions. Due to very low power communication, wireless body area networks are potentially susceptible to interfere with coexisting wireless systems, including other WBANs that might exist in their vicinity. We employ cognitive radios (CRs) for proactive interference sensing in such systems. Our approach insures the channel quality evaluation reducing the packet loss rate and mitigate interferences. On one hand, the intra-WBAN interference is managed through FTDMA protocol. On the other hand, if a high intensity of interference is detected, this solution allows switching channel transmission, thereby ensuring the coexistence of WBANs. Moreover, we modeled the functioning of this method using the Markovs chains in continuous time. The Transmission error rate is introduced as a measure to quantify the effectiveness of the proposed schemes.

Two level evolutionary algorithm for Capacitated Network Design Problem

In this paper, we deal with the Capacitated Network Design Problem (CNDP) with modular link capacities to design minimum cost network while satisfying the flow demands. We propose a two level Genetic Algorithm (GA) based model that can deal with several variations of CNDP. Our proposition defines a new encoding scheme to treat the modular case. Extensive simulation results on Atlanta, France and Germany network instances show that the proposed algorithm is much more efficient than the Iterative Local Search algorithm.