Physical layer study in a goal of robustness and energy efficiency for wireless sensor networks

In this paper we propose a method to specify a robust and energy efficiency physical layer for wireless sensor networks. Thus, from an energy model we show the influence of the channel on energy consumption. Our channel model is a realistic propagation model that takes into account all environmental specificity (geometric, electric) according to a real environment. The Bit Error Rate (BER) is used to assess the radio link quality and calculate the energy per bit transmitted successfully. Simulation results show clearly that significant gains are obtained by adjusting the transmission power in function of the kind of link between the central node and individual nodes. This study show also the importance of a cross-layered approach to optimize effectively the robustness and the lifetime of a wireless sensor network.