Optimal Number of Clusters in Dense Wireless Sensor Networks: A Cross- Layer Approach

Abstract-Cluster-based sensor networks have the advantages of reducing energy consumption and linkmaintenance cost. One fundamental issue in clusterbased sensor networks is to determine the optimal number of clusters. In this paper, we suggest a physical (PHY)/medium access control (MAC)/network (NET) cross-layer analytical approach to determine the optimal number of clusters with an objective of minimizing energy consumption in a high density sensor network. Our cross-layer design can incorporate many effects, including lognormal shadowing and two-slope path loss model in the physical layer, various MAC scheduling and multi-hop routing schemes. Compared with the base-line case with one cluster per observation area, a sensor network with the proposed optimal number of the clusters can reduce energy consumption by over 80% in some cases. We also verify by simulations that the analytical optimal cluster number can still function effectively regardless of different density of sensors in various observation areas