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International audience; The emergence of new technologies make possible the design of new mobile services which are better suitable for cultural and industrial needs. In the context of a museum tour, mobile services allow visitors to obtain rapidly all the information useful for their visit. In this article, we present a mobile service in a wireless-optical network to provide an interactive tour, that is visitor guidance in the museum and multimedia contents on artworks of interest. The considered network architecture is composed of a wireless and an optical part which offer a high throughput (at most several gigabits per second). The proposed service is built for Android smartphone equipped with a Bluetooth card (for indoor localization) and the mDNS (Network Service Discovery for Android) technology (to advertise and share contents with other visitors in a mobile-to-mobile ad-hoc network). In the end of the paper, we give some performance analysis of the proposed mobile service in real situations.

L?arrivée de nouvelles technologies dans les réseaux de communication, permet de concevoir de nouvelles applications mieux adaptées aux besoins culturels et industriels. Dans le contexte de la visite d?un musée, cet article décrit tout d?abord l?architecture du réseau permettant de transporter les informations à très haut débit. Cette architecture de réseaux se base sur les technologies sans fil et optique offrant un haut débit de l?ordre de quelques gigabits par seconde. Ensuite, nous présentons une application de visite interactive suivant un parcours dynamique installée sur un smartphone sous Android. L?implémentation de cette application est basée sur une étude des algorithmes concernés. Cette étude nous a permis de sélectionner l?algorithme NN qui est adapté à un guidage interactif en fonction de critères liés aux souhaits du visiteur.

Grâce à l?évolution de la micro-électronique et de l?informatique, il est possible d?utiliser des dispositifs captant des données sur leur environnement et capables de s?adapter à un grand nombre d?applications tels que la supervision de sites énergétiques, la santé publique ou encore la surveillance d?environnement. Depuis une dizaine d?années, les réseaux de capteurs sans fil se sont répandus pour répondre à de nouveaux besoins introduisant de nouvelles contraintes à prendre en compte, par exemple le délai d?acheminement, des quantités croissantes de données ou encore la mobilité. C'est contraintes supplémentaires nécessitent d'assurer une connectivité plus efficace et plus fiable dans les réseaux de capteurs. Dans ce contexte, la principale motivation de cette thèse est d?étudier et proposer de nouvelles approches permettant de réduire la consommation énergétique des capteurs tout en ayant des garantis de performances sur un ou plusieurs critères secondaires, important d?un point de vu applicatif. De plus, il faudra prendre en compte la dynamicité du réseau du fait de pannes ou de n?uds mobiles.

The clustering algorithm is one of technique used to reduce energy consumption. It can increase the lifetime and the scalability. Energy-efficient protocols should be designed for the characteristic of heterogeneous wireless sensors networks. In PC-LEACH, the cluster-heads are elected by a probability based on the min distance between node and base station. The epochs of being cluster-heads for nodes are different according to their position compared with others nodes and the base station. The key point consideration in this paper, we presents a briefly overview about the techniques of sensor movement followed by description of our scheme based on clustering protocol for wireless sensor networks. We implement and evaluate the performance of our scheme via simulation in diverse network settings and comparatively to related state of the art solutions. Computational results demonstrate the efficiency of the proposed algorithms.

Over the recent years, the Synchronization challenges in wireless sensors networks has been a hot topic and continues to be as an active research area in the last few years. However its importance is shown in the way to better organizing the sensors into the network, to communicate with each other via radio links for sharing and Treatment of reliable information. The main topic in this paper, we propose an improvement over Timing-Sync for sensor Networks (TPSN) to synchronize nodes in a wireless sensors network more effectively, with a good precision and lower missed messages. The simulation result using ns-2.34 shows that this protocol has better synchronization accuracy and low missed messages as compare to TPSN.

Wireless sensors networks consist of a number of sensors nodes connected through a wireless network that collect datato be treated locally or relayed to the sink node using multi-hop wireless transmission. Several solutions were proposedto minimize the amount of information flowing within the network. Clustering algorithms is one solution andmechanism that enables the creation of sensor?s clusters; each sensor is dominated by elected routers. In order to limitenergy consumption, the clustering around the sensor is established: sensors linked to the router transmit relayed datathereafter outward. The number of messages sent and the transmission range are thus reduced. This article tackles thisissue by unveiling proposed techniques in the same line of researches and proposing a clustering mechanism based onthe amount of energy remaining in the sensors. The simulation results show that proposed method can achieve highernetwork lifetime by comparison to original LEACH.

Time synchronization become in recent years as a part and parcel for any distributed system such as sensors net- works. Many applications of sensors networks need local clocks of sensors nodes to be synchronized and keep synchronization between sensors, to communicate with each other via radio links for sharing and treatment of reliable information. The key point of consideration in this article is to examine and evaluate the most important synchronization algorithms based on a set of factors like energy efficiency, mobility and complexity. key words: Time synchronization, Algorithms, wireless sensor network, Data fusion.

Mobile IPv6

Pervasive Computing Environmen