The current trend in wireless sensor networks is to have a single network supporting serveral applications and providing several QoS. In this thesis, we study the cross-layering techniques in order to improve the network performance and provide several QoS. Fistly, we generalize the concept of the access method MaCARI by proposing a multi-stack architecture in which several MAC-routing combination protocols are used. A queue is associated to each combination, and each combination is active for a specified period. The purpose consists in using these combinations in order to provide different QoS. However, this architecture yields to a dimensioning problem for the periods reducing the network performance. Secondly, we propose cross-layering techniques by exchanging packets between different queues to solve the dimensioning problem. During its period, each combination treats all the packets of its queue and the packets related to queues associated to other periods. We show by simulations that our approach improves the network performance.
