Relay node placement algorithm in wireless sensor network

In a two-tier wireless sensor network (WSN), the relay nodes act as the cluster heads for data aggregation and dissemination to the base station. It is very crucial and difficult to find the proper position where the relay nodes can be placed so that the WSN is fully covered and connected. In this paper, we propose an algorithm for placing minimum number of relay nodes with full coverage and connectivity of the WSN with the constraint of minimizing the overall communication cost. The algorithm is based on spiral sequence generated for arbitrarily deployed sensor nodes. The simulation results demonstrate the effectiveness of the algorithm.