Lifetime optimization in hierarchical wireless sensor networks

Wireless sensor networks is a voracious field for research, especially after the great advances in MEMS based sensors. In this paper, environmental monitoring applications are considered where data may be continuously reported with the possibility of urgent alarming if necessary. Hierarchical architecture of the network is assumed in order to overcome the problem of energy constrained sensors. Two algorithms are proposed with the purpose of network lifetime elongation and the maximization of the use of the available energy. The first algorithm is a modification for LEACH-C to enhance its performance. It results in a 25% longer lifetime. The second algorithm is an energy efficient method to ensure full coverage of the network as long as sensors are still working. This achieves 32% longer lifetime than LEACH-C.

1. Introduction

Deployment of large scale as well as small scale Wireless Sensor Networks (WSN) has come into wide use owing to the rapid achievements in MEMS technologies, wireless communications and digital electronics [1]–[3]. WSNs have drawn great interest due to their wide range of applications including physical environment monitoring, security surveillance, military applications and others [4]. An example of the environmental applications is the detection of toxic gases in habitable areas and the measurement of their percentage in air. Due to the limited energy resources of sensor nodes, designing efficient routing protocols has been one of the most challenging issues for WSNs [4]. One main concern for WSNs is to make best use of the network and maximize its lifetime.