Optimization of Clustering Techniques with Density Control in Wireless Sensor Networks

Abstract

Wireless Sensor networks are composed of large number of sensor nodes with batteries having low capacity. Wireless networks of thousands of inexpensive tiny devices are ca-pable of communication, computation and sensing. A sensor node has limited capability of sensing, computing, storing and transmitting data. Wireless Sensor networks provide a bridge between the real physical and virtual worlds. Clusters are created in group of sensor nodes. The Hierarchical routing is used for cluster formation for utilization of the resources of the sensor nodes. LEACH and LEACH-C are energy efficient routing proto-cols. Here we compare various Wireless Sensor Network(WSN) clustering protocols like LEACH-C, Kmeans and its variants. The protocols have been compared with respect to network lifetime, data delivery and energy consumption. These protocols only consider intra cluster distance of members while clustering. A cluster size control approach is proposed which balances cluster member assignment in a dynamic way. A Loose Size Control(LSC) based approach has been implemented with K-Means clustering technique. LSC based approach shows improved average data delivery per node with similar energy usage when compared to other protocols. It also helps in improving network lifetime. Also an evolutionary protocol based on Harmony Search method has been proposed with certain improvements like intra-cluster distance based clustering. It has been compared with various conventional clustering methods and GA based approaches. The proposed approach shows improvements in clustering process and overall data delivery improves along-with considerable improvements in network lifetime.