Communication restoration within wireless sensor networks

Abstract

The deployed base stations within a wireless sensor network (WSN) serve as an intermediate node in connecting the sensors to the central server. The base stations are vulnerable to malfunction failures, which may disconnect a set of sensors linked to the failed base station. This disconnection decreases the connectivity and the lifespan. In this paper, we have considered the WSN operations during base station failures and we have proposed a communication restoration framework to restore the failed communications without adding new base stations. We have considered the layout of WSN as a linear grid platform, whereby the sensors are deployed at the center of each cell and the base stations are deployed at the cell intersections. The sensors are connected in multi-hop tree topology and are grouped into various clusters with each cluster head connected to a nearby base station. On failure of any of the base stations, the restoration framework distributes the disconnected sensors to a nearby base station and if necessary, it relocates the base station to the proximity of the failed one to improve the lifespan and connectivity of WSN. Simulated Annealing aids in relocating the base stations to better locations with minimal energy consumption. The experimental results show that for the given medium size WSN with 25 sensors and 5 base stations with base stations failing consecutively at regular time intervals, the restoration model manages to maintain 100% network connectivity at the expense of 25% reduced network lifespan.