Energy management in solar cells powered wireless sensor networks for quality of service optimization

Sensor nodes equipped with solar cells and rechargeable batteries are useful in many outdoor, long-lasting applications. In these sensor nodes, the cycles of energy harvesting and battery recharge need to be managed appropriately in order to avoid sensor node unavailability due to energy shortages. To this purpose, we suggest sensor nodes to be programmed with alternative scheduling plans, each corresponding to a given energy requirement and meeting a given quality level. Thus, sensor nodes can select the scheduling plan that best suits to the expected energy production and the residual battery charge, in order to avoid sensor nodes' unavailability. We then propose an algorithm for the selection of the scheduling plan that aims at keeping the overall energy consumption neutral and that can sustain the sensor nodes' activities uninterruptedly.