Geographic routing with enhanced local information for wireless networks

Geographic routing provides for network scalability through routing decisions made from local position information. This feature is essentially at the cost of routing path stretch particularly in networks having sparse nodes or holes. To mitigate the unappealing factor, we exploit information on the maximum angle between successive edges from a node, defined as the representative angle of a node that economically characterizes local topology and is also exchanged with neighbors. Besides analyzing its valuable information, we prove that nodes with the representative angle larger than or equal to 5π/3, called corner nodes, can be logically removed from networks without disconnecting a given source from destination. We then propose routing schemes that thoroughly utilize representative angle information and associated design principles to reduce hop counts. In particular, we propose greedy network boundary traversal schemes which overlay the state of the art mechanism by the rotational sweep algorithm based on curved-stick to bypass network voids. Consequently, through excluding corner nodes as relays and taking into account the representative angle of a relay candidate by a weighting function in greedy mode operation and skipping unnecessary hops in recovery mode operation, our routing scheme achieves a remarkable saving of routing hop counts.