This paper discusses the computational approach we have used to devise an optimal mobile communication system (cellular phones) in an urban environment. We rst present a lattice Boltzmann model for simulating wave propagation and taking into account the absorption and reeection of waves over obstacles. Second, we combine this wave propagation model with a genetic algorithm in order to nd the antennas locations which ensure an optimal coverage of a given region of a city. We have considered a parallel implementation of our computation.