Wireless Sensor network is a network of sensor nodes. A sensor node has, in addition to computation, sensing and wireless communication capability. A network of these nodes is deployed to measure the ecological properties like temperature etc. There is a base station which collects the data from these nodes. The data reaches the base station wirelessly by the multihop communication path established by the sensor nodes. The sensor nodes are resource constrained, and communication is the major consumer of battery resource. The nodes near the base station relay other further nodes data, and as a result die earlier. Once they are gone, the network is effectively disconnected. We explore the option of a chargeable mobile base station traversing the network, and the nodes transfer the data when it is near. This improves the lifetime of the network. The work involves designing network algorithms for the system, and adaptive speed control strategies for the mobile.