A clustering/multi-hop hybrid routing method for Wireless Sensor Networks with heterogeneous node types

In recent years, Wireless Sensor Network (WSN) which consists of a large number of sensor nodes having wireless communication and self-organizing capability receives much attention. The design of protocols for such networks has to be energy aware in order to prolong the lifetime of the network. Multi-hop and clustering communication are most efficient routing methods in WSN. Multi-hop communication methods are preferable for traffic distribution in small and dense areas. To the contrary, it is not suitable for wide area WSN due to lack of extensibility. Clustering is one of the promising techniques for WSN because of its good scalability and the support for data aggregation. Though, cluster heads around the sink tend to have heavy traffic. In recently focused heterogeneous WSN models, by introducing a few special nodes with high-end communication capability and extra battery energy, the hardware cost of the rest of the network and communication cost of the sensing nodes can be reduced. In this paper, we propose a robust hybrid routing method for heterogeneous WSN which adaptively combines clustering and multi-hop communication methods which is nodes placed near to sink perform a multi-hop network (multi-hop zone) and nodes far away from sink perform clusters. Furthermore, we approximately analyze spatial boundary between both methods. Simulation results show that our method significantly increases network lifetime in comparison with pure clustering and multi-hop communication methods.