Optimal wake-up scheduling of data gathering trees for wireless sensor networks

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%∼24.3% less average power, and thus resulted in a 7.4%∼26.0% longer network lifetime, than a previously proposed method that did not consider individual data rates.

► We propose an optimal wake-up scheduling algorithm for wireless sensor networks.
► The proposed algorithm minimizes the total power consumption of a sensor network.
► The proposed algorithm considers the delay limit and the data rates of each node.
► Analytical methods are used to prove that the proposed algorithm is optimal.
► Simulations show the superiority of the proposed method over previous methods.