Date: February 10, 2006

Time: 3:00 p.m.

Location: Centergy One 5186

Speaker(s): Dr. Xiaoli Ma

Title: An Efficient Path Pruning Algorithm for Geographical Routing in Wireless Networks

Abstract:
Geographical routing is powerful for its capability to discover sub-optimal route to the destination without the help of global state information. However, detours usually happen when the packet reaches a local minimum and in this case, the network topology has to be reduced to planar graph and recovery schemes such as face routing is then used. Face routing commonly contain a large number of hops on a planar graph. When multiple packets are generated for the same destination, such a large number of hops tends to consume more energy. In this paper, a simple yet effective path pruning strategy is proposed to reduce the excessive number of hops caused by the detouring mode of geographical routing protocols. The path pruning algorithm finds routing shortcuts by exploiting the channel listening capability of wireless nodes, and is able to reduce a large portion of hops with the help of little state information passively maintained by a subset of nodes on the route. Simulation results show that in average the path pruning algorithm can reduce as much as 80% of the hops in the routes obtained by existing geographical protocols such as Greedy Perimeter Stateless Routing (GPSR) and Greedy Other Adaptive Face Routing+ (GOAFR+) in critical network density regions.

Bio:
Dr. Ma received the B.S. degree in Automatic Control from Tsinghua University, Beijing, China in 1998, the M.S. degree in Electrical Engineering from the University of Virginia in 2000, and the Ph.D. degree in Electrical Engineering from the University of Minnesota in 2003. After receiving her Ph.D., she joined the Department of Electrical and Computer Engineering at Auburn University, where she served as an assistant professor until 2005. Since spring 2006, she has been with the School of Electrical and Computer Engineering at Georgia Tech.

Date:	February 10, 2006
Time:	3:00 p.m.
Location:	Centergy One 5186
Speaker(s):	Dr. Xiaoli Ma
Title:	An Efficient Path Pruning Algorithm for Geographical Routing in Wireless Networks
Abstract:	Geographical routing is powerful for its capability to discover sub-optimal route to the destination without the help of global state information. However, detours usually happen when the packet reaches a local minimum and in this case, the network topology has to be reduced to planar graph and recovery schemes such as face routing is then used. Face routing commonly contain a large number of hops on a planar graph. When multiple packets are generated for the same destination, such a large number of hops tends to consume more energy. In this paper, a simple yet effective path pruning strategy is proposed to reduce the excessive number of hops caused by the detouring mode of geographical routing protocols. The path pruning algorithm finds routing shortcuts by exploiting the channel listening capability of wireless nodes, and is able to reduce a large portion of hops with the help of little state information passively maintained by a subset of nodes on the route. Simulation results show that in average the path pruning algorithm can reduce as much as 80% of the hops in the routes obtained by existing geographical protocols such as Greedy Perimeter Stateless Routing (GPSR) and Greedy Other Adaptive Face Routing+ (GOAFR+) in critical network density regions.
Bio:	Dr. Ma received the B.S. degree in Automatic Control from Tsinghua University, Beijing, China in 1998, the M.S. degree in Electrical Engineering from the University of Virginia in 2000, and the Ph.D. degree in Electrical Engineering from the University of Minnesota in 2003. After receiving her Ph.D., she joined the Department of Electrical and Computer Engineering at Auburn University, where she served as an assistant professor until 2005. Since spring 2006, she has been with the School of Electrical and Computer Engineering at Georgia Tech.