Abstract: “We have considered the problem of using static sink for data gathering purpose in an energy constrained multi hop wireless sensor networks. Sensing and relaying the collected data to the sink node using multi hop communication in an energy efficient manner is of prime importance. Optimizing sensor networks involves addressing a wide range of issues steaming from limited energy reserves, computation power, communication capabilities and self managing sensor nodes. In this paper we have investigated the problem of using static sink in case of the sensor networks which results in uneven energy expenditure and also the uneven sensing coverage over different parts of the network. We have used the concept of repositioning of the sink for enhancing the performance of the network in terms of energy which will also help in extending the lifetime of the network. For this we have used the repositioning algorithm which has been simulated in the NS-2.32 environment. Our simulation results show that”

Keywords: Wireless Sensor Networks, ECR, Energy Efficiency, Sink Repositioning