Dynamic Spectrum Sharing in Femtocells: A Comparison of Selfish versus Altruistic Strategies

Dynamic spectrum approaches are steadily gaining momentum, especially in the context of femtocells. Yet designing efficient, stable, fair and scalable distributed algorithms is no easy feat, specially if the cells in a wireless network tend to act selfish and independently. Game Theory is a powerful toolbox which models the interaction of autonomous agents. In this paper we present a game theoretic model for a dynamic spectrum sharing framework recently proposed for femtocells. Our analysis includes cases where femtocells compete for spectrum as well as cooperative cases towards a common goal. The system level simulation results show that strict adherence to the game-theoretic selfish behavior performs poorly compared to the non-adherent rules which balance altruism and rational egoism. The main conclusion is that practical solutions should be guided but not limited by purely theoretical assumptions.