A generalized spatial boundary analysis method for clustering/multi-hop hybrid routing in Wireless Sensor Networks

In recent years, Wireless Sensor Network (WSN) which consists of a large number of sensor nodes having wireless communication and self-organizing capabilities receives much attention. Also, recently heterogeneous WSN models are focused on. 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. 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 communications are most efficient routing methods in WSN. In our previous research, we proposed a hybrid routing method for heterogeneous WSN which adaptively combines clustering and multi-hop communication methods, in which nodes placed near to sink perform a multi-hop network (multi-hop zone) and nodes far away from sink perform clusters (clustering zone). In that method, we focused on a very basic network topologies which are circular network areas and sink is placed on center of the area. Therefore, we had some technical difficulties to apply our method for typical WSN with complex network boundaries and optimal sink locations. In this research, we propose a novel and generalized analytical method which can flexibly include the constraints on the physical network boundaries and location of the sink to define the spatial boundary between clustering and multi-hop zones. Simulation results show that our method significantly increases network lifetime in comparison with pure clustering and multi-hop communication methods.