AN HW RECONFIGURABLE NODE WITH NOVEL SCHEDULING IN AN ENERGY-HARVESTING ENVIRONMENT

One fundamental constraint of wireless sensor network (WSN) is the ratio of the power consumption to the energy supply. Recent studies have shown that building WSN nodes with solar-energy harvesting capability is an effective approach to lengthening the lifetime of node. Meanwhile, the partial dynamic reconfiguration (PDR) is a productive approach in intensive applications such as video and encryption processes. For PDR, time and energy must be invested before an application can be running. Thus, this method is different from the software approach. Therefore, in an energy-harvesting system, the scheduling of tasks in the form of software or hardware is important. In this paper, a novel methodology that schedules dynamic reconfigurations for a WSN node with an energy-harvesting is presented. This method is based on statistical data on tasks and available energy. To demonstrate this approach, an HW reconfigurable WSN node is prototyped. Four typical applications are used as test cases and are divided into basic scheduling units. In the experiments, the efficiency of reconfigurable hardware is first demonstrated. The novel scheduling strategy is then used to identify the most valuable application for the reconfigurable hardware. Our experiments demonstrate that more than 50% energy cost can be saved compared with the software-based solution.