Abstract: Energy saving is a critical issue in Wireless Sensor Network as they have limited amount of energy. In WSN Sensor node closer to the sink will exhaust their limited energy more rapidly than other sensor nodes, since they will have to forward huge data during multi hop transmission to the base station. Therefore network lifetime will be reduced because of hotspot problem. To cope up with the network lifetime, in this paper, Novel Energy Efficient Unequal Clustering algorithm for clustered wireless sensor network is proposed, the decision of selecting cluster heads by the sink is based on the residual energy and distance to the base station, Besides, the cluster head also selects the shortest path to reach the sink. Simulation results show that our approach enhanced the performance than traditional routing algorithms, such as LEACH & EEUC.

Keywords: Residual energy, Unequal clustering, Routing, Network lifetime, Hot Spot problem.