Enhanced Unequal Clustering Scheme for Wireless Sensor Networks

In wireless sensor networks, the lifetime of a sensor network is a hottest research topic. Clustering provides an efficient method for increasing the network lifetime. Existing clustering algorithms selects the cluster head with high residual energy and rotates the cluster head periodically to distribute the energy among the nodes in each cluster. Cluster head has the responsibility for collecting data from its cluster members and then it forwards them to the base station. As a result, each node spends more energy for re-electing the cluster head frequently and gathering data from its cluster members. The hot spot problem and distributing the energy consumption among the nodes are the major issues in clustering. To mitigate the hot spot issue and preserve energy for multihop data forwarding, an enhanced clustering scheme namely EUCS is proposed. It constructs the clusters of unequal size and clusters closer to the base station have smaller in size. The cluster head can be re-elected when the energy level of current cluster head reaches to its predefined threshold value which reduces the frequent re-election of cluster head. In addition, to preserve some more energy, data from the sensor nodes are directly transferred to the nearest cluster heads which forwards them to the base station to avoid data gathering in the cluster head. The simulation results show that our algorithm increases the network lifetime effectively. General Terms Wireless Sensor Networks, Clustering.