Cooperative communication with joint optimization of cluster size and resource allocation in wireless sensor networks

Cluster-based wireless sensor network is considered in this paper. In wireless sensor network, every node wants to send data to a certain gateway node, or command node in case of military sensor network. Cluster-based communication enables effective power control, while the power budget of wireless sensor nodes is limited. In the conventional clustering algorithm, there is the cluster header node which has comparatively large capacity. However, in most cases, every node has the same power budget and all nodes behave symmetrically. It is necessary to design cluster based on this equivalent node condition. In this paper, we design optimal cluster size based on the outage probability under Rayleigh fading channel. A node who wants to send data to the gateway node adaptively constructs a cluster based on joint power minimization problem of cluster size and resource allocation. After making the cluster, the header node can cooperatively send packets with the member nodes of its cluster. This optimized cluster design shows outstanding power reduction compared to conventional clustering algorithm in which cluster header node directly transmits to the gateway node.