The wireless sensor networks (WSN) are particularly vulnerable to various attacks at different layers of the protocol stack. Many intrusion detection system (IDS) have been proposed to secure WSNs. But all these systems operate in a single layer of the OSI model, or do not consider the interaction and collaboration between these layers. Consequently these systems are mostly inefficient and would drain out the WSN. In this paper we propose a new intrusion detection system based on cross layer interaction between the network, Mac and physical layers. Indeed we have addressed the problem of intrusion detection in a different way in which the concept of cross layer is widely used leading to the birth of a new type of IDS. We have experimentally evaluated our system using the NS simulator to demonstrate its effectiveness in detecting different types of attacks at multiple layers of the OSI model.

In multi-hop ad hoc networks, queuing resources become unavailable under high load. When the traffic increases, the received frames are generally dropped and retransmitted later by the senders after a short timeout. This situation led to more conflicts in accessing the wireless medium and decreases the network performances. In this paper, we propose a new scheme to avoid the bad utilization of wireless medium in high load conditions. Simulations under NS2 have been conducted to study QoS parameters, especially throughput, delay and jitter. The obtained results show that the performances of our proposal are better than those of IEEE 802.11.

Pour faire face à la croissance du nombre d’internautes à travers le monde, des liaisons à des débits de plus en plus élevés sont nécessaires; En plus, la mise en place de routeurs de plus en plus performants est primordiale pour suivre cette évolution. Une des opérations influentes sur la performance globale d’un routeur est la recherche de l’information dans la table de routage. Nous proposons dans cet article, une architecture parallèle pour la recherche de routes dans les tables IP. À la différence d’autres approches, nous proposons un mécanisme qui utilise le critère de longueur des préfixes pour regrouper les préfixes dans des sous tables de routage équilibrées, qui seront ensuite manipulées parallèlement afin d’accélérer l’opération de recherche des adresses IP par le routeur..