NHCDRA: a non-uniform hierarchical clustering with dynamic route adjustment for mobile sink based heterogeneous wireless sensor networks

In wireless sensor networks (WSNs), various routing protocols have been proposed based on clustering to achieve energy efficiency. The performance of such routing protocols can further be improved by deploying heterogeneous sensor nodes since responsibilities can be divided among different sensor nodes according to their heterogeneity. In this paper, we propose a novel non-uniform hierarchical clustering with dynamic route adjustment scheme, termed as NHCDRA, for heterogeneous WSNs considering two mobile sinks moving around the periphery of the sensor field. NHCDRA divides the sensor field into several non-uniform sized hierarchical clusters. The size of boundary clusters (near to the sink's mobility path) is kept relatively large to accommodate more number of sensor nodes so that the responsibilities of cluster heads can be rotated efficiently to distribute the load. Furthermore, a set of dynamic route adjustment rules are defined to manage the routing paths as a consequence of mobility of the sinks. These rules reduce the overhead of route adjustment as well as ensure data delivery to the sink in minimal number of hops. Simulation results show that NHCDRA significantly reduces the data delivery delay and improves network lifetime when compared with state-of-the-art.