AN ENERGY EFFICIENT MOBILE SINK PATH SELECTION TO IMPROVE THE LIFE TIME FOR WIRELESS SENSOR NETWORKS

Using a mobile sink to reduce the energy consumption of nodes and to prevent the formation of energy holes in wireless sensor networks(WSNs).Benefits are dependent on the path taken by the mobile sink, particularly in delay sensitive applications ,as all sensed data must be collected within a given time constraint. An approach proposed to address this challenge is to form a hybrid moving pattern in which a mobile sink node only visits rendezvous points (RPs), as opposed to all nodes. Sensor nodes that are not RPs forward their sensed data via multi-hopping to the nearest RP node. Fundamental problem becomes computing a tour that visits all the RPs within a given delay bound. Identifying the optimal tour, however is an NP hard problem .To address this problem Weighted Rendezvous Planning (WRP) method is proposed whereby each sensor node is assigned a weight corresponding to its hop distance from the tour and the number of data packets that it forwards to the closest RP.WRP enables a mobile sink to retrieve all sensed data within a given deadline while conserving the energy expenditure of sensor nodes. More specifically, WRP reduces energy consumption and also increases the network lifetime as compared with existing methods.