Look-ahead geographic routing for sensor networks

As sensor networks are deployed over various terrains, the complexity of their topology continues to grow. Voids in networks often cause existing geographic routing algorithms to fail. In this paper, we propose a novel geographic routing algorithm called ldquoGreedy Forwarding with VIrtual Position (ViP)rdquo. We introduce virtual position as the middle position of all direct neighbors of a node. Instead of comparing nodes´ real geographic positions, ViP employs virtual positions when selecting the next hop. Such virtual position reflects the neighborhood of a sensor node, as well as the tendency of further forwarding. For sparsely-deployed networks, ViP increases success rate of packet routing without introducing significant overhead. Furthermore, multiple levels of virtual position can be obtained with localized iteration. We propose the ldquogreedy forwarding with Multi-level Virtual Position (MVP)rdquo algorithm and the ldquoGreedy Forwarding with Hierarchical Virtual Position (HVP)rdquo algorithm. Different levels of virtual positions and their combinations are used alternatively to increase success rate of packet routing in sensor networks.