Lifetime prolongation of PARC-based wireless sensor networks by mobile sink method

In a wireless sensor network composed of battery-powered sensor nodes, the saving of battery power consumptions of sensor nodes is essential to prolong the lifetime of a wireless sensor network. For this purpose, we have proposed the PARC method, which improves the efficiency of multi-hop communication in wireless sensor networks. However, even in case of using the PARC method, a hot spot problem occurs at node around a sink. Due to this problem, batteries of nodes around the sink are depleted early, and the sink cannot collect any sensing data. In this paper, in order to cope with this problem, we introduce a mobile sink method for the PARC method. The proposed mobile sink moves around plural pre-assigned data collecting points periodically. In order to balance the load among nodes, the data collection times at each stopping point should be optimized. We propose a simple optimization method of data collection times and show the effectiveness of our method by simulation experiments.