Variable frame slot clustering scheme for data gathering wireless sensor networks

Wireless sensor networks are data centric networks. Clustering of nodes is an energy efficient approach that improves the data rate of networks. E-LEACH is an energy efficient approach based on clustering. E-LEACH does not guarantee the even distribution of nodes in the clusters. Uneven size of clusters affects the load balancing of networks because TDMA schedule of nodes of smaller cluster is smaller than others that results more number of data frames per node. In this paper, a variable frame slot scheme is proposed with E-LEACH. Variable frame slots for clusters make network more load balanced. Simulation is carried out in NS-2 to analyze the node death rate and data units gathered with node death rate for E-LEACH with variable frame length. Variable frame slot scheme for clusters is also measured with the varying distance of base station from the field. Simulation results show that E_LEACH with variable frame length has an improvement of 7% in node death rate over E-LEACH and an improvement of 5% in data gathering with node death rate. Results suggest that variable frame length scheme improves the performance of E_LEACH scheme for Wireless Sensor Networks and have most significant result at base station located at 75m from the field.