Network selection games: simulation tool development and performance evaluation = Selección de redes mediante juegos: desarrollo de herramienta de simulación y evaluación de rendimiento

The present thesis work is motivated in the recent developments of wireless access technologies, which have given noticeable changes on both operator and end-user side. From the operator side, the wireless access networks have evolved from 1st generation technologies (1G) up to 3rd generation technologies (3G) during the last three decades. Additionally, 4th generation networks (4G) based in advanced radio technologies are already in development phases. The proliferation of wireless access networks yields opportunities to the end-user, however it can also induce a additional problematic due to the complexity of the network to be operated. Therefore, the end-user has the possibility to choose dynamically which access technology (access network) to connect to, in order to obtain the required service. From the moment the decisions from the users occur in a distributed, non-coordinated and generally opportunistic way, the access to wireless networks process dynamics are in a need to be studied. The present thesis work, analyses the competitive access problem by means of game theory. In particular, non-cooperative game models in which the users tend to maximize their individual utility from the access problem are considered. The thesis work presents the development and implementation of a software instrument capable of simulating game dynamics individualizing equilibria conditions and measuring the transition length to reach such equilibria (convergence time). The second part of the thesis work includes the analysis of different realistic wireless access networks considering different access strategies which are selected by the end-users and different utility function formulations with which the players “play” the game