Dual Priority Scheduling Based on Power Adjustment Context Switching for Ubiquitous Sensor Network

The Ubiquitous sensor network (USN) node is required to operate for several months with limited system resources such as memory and power. The typical USN node is in the active state for less than 1% of its several month lifetime and waits in the inactive state for the remaining 99% of its lifetime. This paper suggests a power adjustment dual priority scheduler (PA-DPS) that offers low power consumption while meeting the USN requirements by estimating power consumption in the USN node. PADPS has been designed based on the event-driven approach and the dualpriority scheduling structure, which has been conventionally suggested in the real-time system field. From experimental results, PA-DPS reduced the inactive mode current up to 40% under the 1% duty cycle. key words: Ubiquitous sensor networks, dual priority schedule, operating system