Geographic convergecast using mobile sink in wireless sensor networks

This paper presents a novel convergecast algorithm called, Virtual Circle Combined Straight Routing (VCCSR), which collects data in a wireless sensor network (WSN) using a mobile sink. Tree-based routing offers the shortest routes to deliver data, and it is a common scheme used by mobile sinks to collect data from sensors. When a mobile sink moves, the routes between the sink and the sensors must be reconstructed dynamically, which wastes a great amount of energy. VCCSR selects a set of cluster heads located near the virtual backbone, and when the sink issues a query in the WSN, a spanning tree is constructed to collect and complete data periodically. With VCCSR, the spanning tree does not need to be reconstructed when the mobile sink's location changes because the algorithm is able to update the location of the mobile sink, which then delivers this information to the cluster heads and adjusts the routing. The goal of the proposed algorithm is to decrease the reconstruction cost and increase the data delivery ratio. In comparing the VCCSR protocol with BFS tree-based protocols in simulation, this paper demonstrates that the spanning tree adjustment process executed by VCCSR does in fact decrease the reconstruction cost and increase the data delivery ratio.