Small World Topology-Aware Geographic Routing in Wireless Sensor Networks

Geographic routing, based on greedy forwarding, relies on topology knowledge of the node's neighbors and achieves short path in the well-connected sensor networks. However, because of the absence of the topology knowledge outside of the neighborhood, the forwarding technique fails in the presence of void area. With the void-handling techniques, the geographic routing will experience non-short path and thus consume a large amount of energy. In this paper, a new concept of the topology knowledge, topological awareness, is proposed, which provides a node with myopic topology knowledge (neighbor nodes) and non-myopic topology knowledge (non-neighbor nodes). These non-neighbor nodes are discovered based on a small world model, such that a logical small world network is constructed. A novel geographic routing, called small world topology-aware routing (SWTAR) is proposed. It is demonstrated that SWTAR greatly enhance the packet delivery ratio without the need of the void-handling techniques and experience nearly shortest forwarding path, especially in the network seriously obstructed by obstacles.