ABSTRACT
This chapter describes several node-level energy reduction methods for in wireless sensor networks. Designers of embedded processors that are used in sensor nodes include variable-voltage power supplies in their processor designs, i.e., the supply voltages of these processors can be adjusted dynamically to trade-off performance with power consumption. Switching between device power states incurs a time penalty, i.e., a device takes a certain amount of time to transition between its power states. The chapter also describes an optimal offline algorithm that generates device schedules for minimum energy consumption of I/O devices in hard real-time sensor nodes. Energy is an important resource in battery-operated sensor systems. The relatively low complexity of multi-state constrained low energy scheduler makes online device scheduling for low energy and real-time execution feasible. CPU-centric and I/O-centric dynamic power management (DPM) techniques have emerged at the forefront of DPM research for wireless sensor networks.
