Topic：Geographic routing with enhanced local information for wireless networks

Date&Time：2015/4/24(五) 14:20

Speaker：蔡榮宗教授 (台灣師範大學資工系)

Location：清華大學台達館 R216

Abstract：
Geographic routing ensures 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 (RA) of a node that economically characterizes local topology and is also exchanged with neighbors. We find that nodes with RA larger than or equal to 5pipi/3, called corner nodes, can be logically removed from networks without disconnecting a given source from destination. We propose routing schemes that thoroughly utilize RA information either to improve routing success rates for best-effort routing or to reduce hop counts for reliable routing. In particular, we propose greedy network boundary traversal schemes which overlay the state of the art mechanism by Twisting-Triangle (TT) sweeping. Consequently, through excluding corner nodes as relays and taking into account RA by a weighting function during greedy forwarding and skipping TT-hit nodes proven to be unnecessary hops during network boundary traversal, our routing scheme achieves a remarkable saving of routing hop counts.