Impact of Sleep on PHY-MAC in UWB Networks

Energy conservation is an important issue in wireless networks, especially for self-organized, low power, low data-rate impulse-radio ultra-wideband (IR-UWB) networks, where every node is a battery-driven device. To conserve energy, it is necessary to turn node into sleep state when no data exist. This paper addresses the impact of two kinds of sleeping protocols (slotted and unslotted) on PHY-MAC in UWB networks. We introduce an analytical model for energy consumption of a node and evaluate the performance of the proposed sleeping protocols. Simulation results show that the energy consumption per packet of slotted sleeping is less than that of unslotted one for bursty load case, but with respect to the load access delay unslotted one consumes less energy, that maximize node lifetime.