La soutenance aura lieu à Grenoble INP - PHELMA dans l’amphithéâtre P015 (23 Rue des Martyrs, Grenoble), devant le jury composé de :
— Prof. Vivien Quéma (Grenoble INP–Ensimag, Président)
— Prof. Isabelle Guérin-Lassous (ENS de Lyon, Rapporteur)
— Prof. Fabrice Valois (INSA de Lyon, Rapporteur)
— Prof. Maria-Gabriella Di Benedetto (Université de Rome "La Sapienza", Examinatrice)
— Prof. Andrzej Duda (Grenoble INP–Ensimag, directeur de thèse)
— Dr. Emilio Calvanese-Strinati (CEA-Leti, Grenoble, co-directeur de thèse)
In this PhD thesis, we consider heterogeneous Wireless Sensor Networks (WSNs) in which several sensing devices with different characteristics coexist. In contrast to a homogeneous sensor network, in heterogeneous networks different sensors may sense different physical phenomena generating traffic that have different characteristics such as monitor- ing temperature, pressure, and humidity, thereby introducing different reading rates at the sensors. Moreover, also information criticality can be heterogeneous. Deployment of nodes also introduces heterogeneity in the network. Depending on the specific application in fact, initial deployment can be random with the result that the distribution of nodes across the playground may be non-homogeneous. In addition to this, during the network life other factors influence the heterogeneity of the distribution of nodes. Some examples are the node death because of energy resource exhaustion or generic fault, the roll-out of new devices, and the mobility of nodes. All these characteristics can be considered as sources of heterogeneity of a WSN. Heterogeneity conditions may evolve during time and space, therefore, the design of a heterogeneous sensor networks requires adaptive mechanisms able to react to different characteristics, which is difficult to achieve. The goal of the thesis is to investigate the problems related to heterogeneity of sources in WSNs to design adaptive MAC methods that are able to take into account heterogeneity variations and are energy-efficient. We focus on two sources of heterogeneity.