Optimal Wake-Up Scheduling of Data Gathering Trees for Wireless Sensor Networks

Abstract

In order to gather sensor data, a data gathering tree is commonly created as a subnetwork of a wireless sensor network. Power conservation is of paramount importance in such networks, and using periodic sleep-wake cycles for sensor nodes is one of the most effective methods for power conservation. This paper addresses the problem of scheduling the sleep-wake cycles of nodes in a data gathering tree under deadline constraints. After formally modeling the problem being addressed, an optimal wake-up frequency assignment (OWFA) algorithm, which takes into account the data rate at each node and the total permitted delay, is proposed. The results of simulations under various conditions showed that OWFA consumed about 8.6% similar to 24.3% less average power, and thus resulted in a 7.4% similar to 26.0% longer network lifetime, than a previously proposed method that did not consider individual data rates. (C) 2012 Elsevier Inc. All rights reserved.