An Uncapacitated Facility Location Based Cluster Hierarchy Scheme on Wireless Sensor Networks

Cluster-Head (CH) nodes function as gateways between the sensors and the Base Station, in Wireless Sensor Networks with a cluster hierarchy. The total energy dissipation of the sensors can be reduced by optimizing the load balance within the cluster hierarchy. This paper proposes an uncapacitated facility location based cluster scheme in which the system lifetime is extended by adding an additional layer of SuperCluster-Head (SCH) nodes, in order to ease the transmission load of the CHs and to balance the load distribution within the network. The SCH layer is configured using an uncapacitated facility location algorithm in which the facility and service costs are defined in terms of both the energy and the transmission distance. The simulation results confirm that the proposed method yields a better load balance in the SCH layer than that obtained using either a random configuration or a round-robin scheme. Finally, it is shown that irrespective of the size of the sensor field, the proposed scheme outperforms the conventional LEACH-C two-layer scheme in terms of the average energy dissipation of the nodes, the average survival times of the nodes, and the overall system lifetime. Key-Words: Wireless Sensor Network, Gateway Node, Cluster hierarchy, Uncapacitated Facility Location Problem