| Summary: | 碩士 === 國立臺灣師範大學 === 資訊工程研究所 === 100 === Many geographic routing protocols for wireless ah-hoc network have been proposed in the literatures in recent years. In geographic routing, each node in networks is aware of the location itself by GPS. The solution of local minima problem is Greedy Perimeter Stateless Routing (GPSR). However, in GPSR, when packets enter perimeter mode, hop count will increase because of right-hand rule. To improve this problem, we provide two algorithms to achieve Dead-end reduction. The essential technique employed is to divide neighbor nodes into two groups according to location information and angles between each pair of circularly consecutive neighboring nodes.
In the thesis, we propose a Quasi Greedy Geographic routing (QGGR) algorithm in which a constant threshold θt is used to determine a partition of neighbor nodes into two groups. The group of neighbor nodes with max angle less than θt has higher priority than other group in the process of greedy forwarding. Furthermore, we introduce a Dynamic-Quasi Greedy algorithm in which the threshold θt is adapted according to the distance between current node and destination node. The simulation results show that QGGR and DQGGR could achieve better hop count performance and Dead-end reduction than GPSR.
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