Recently, the pervasive and critical nature of embedded systems like wireless networks has grown rapidly in the world of research. This growth has nowhere exempt end-user to bene t from the contributions of these technologies in everyday life. In parallel, a lot of problems have emerged and led to the call of the scienti c community and researchers to look for solutions. In their architecture, the batteries's sensors can not be replaced or charged. To this point, many works consider reducing the energy consumed during the capture, processing and transmission of data. It is in this context that our works was oriented to energy consumption in WSN (Wireless Sensor Networks) considered as a major constraint and problematic. In fact, our contribution through this thesis discusses works bearing on energy optimization techniques in WSN, considered as an Ad-hoc network. To surpass the known challenges and constraints, we act on several sensor functions to look for an optimal con guration which economize more energy of sensor and maximize the network lifetime. In add to the energy optimization, the presented work adapts the results and solutions to numerous application like transport, health control, security and indoor areas. To carry out our work, we began by conducting a comparative study of communications technologies functions in WSN. Being emerged on topics related to news on wireless sensor networks, we treated on the next the localization function by the use of the energy of transmission. Subsequently, we discussed the security function by a new approach based on the notion of agent. Finally and in the routing function, a new algorithm is presented to minimize the network load caused by the route discovery mechanisms RREQ (Route REQuest). As an application, a deployment architecture, location and health monitoring of pilgrims is proposed for implementation in the areas of the Great Mosque of El Hajj. Brie y, this work contributes advantageously to optimize and improve battery power of sensors in the context of their use or application domain that in uences more this consumption.
