| Speaker: | Dr. Konstantinos Psounis, University of Southern California |
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| Abstract: | Intermittently connected mobile networks are wireless networks where most of the time there does not exist a complete path from the source to the destination. There are many real networks that fall into this paradigm, for example, wildlife tracking sensor networks, military networks, inter-planetary networks, ad hoc vehicular networks, etc. In this context, conventional routing schemes fail. To deal with such networks researchers have suggested to use flooding-based routing schemes. While flooding-based schemes have a high probability of delivery, they waste a lot of energy and suffer from severe contention for network resources which can significantly degrade performance. With this in mind, in this work we explore the design space of routing schemes for such networks and propose efficient routing schemes to overcome these shortcomings. We use theory and simulations in order to evaluate the performance of a number of practical schemes. We show that the champion algorithm is a routing scheme we call Spray and Wait, that "sprays" a number of copies into the network, and then "waits" till one of the relay nodes meets the destination. We also state and analyze the performance of an optimal algorithm that minimizes the message delivery delay. Our analysis shows that Spray and Wait has a number of desirable properties: it is very simple to implement, it is highly scalable, it performs very close to the optimal scheme, and quite surprisingly, it outperforms all existing practical schemes with respect to both average message delivery delay and number of transmissions per message delivered. |
| Biography: | Konstantinos Psounis is an assistant professor of Electrical Engineering and Computer Science at the University of Southern California. Konstantinos received his first degree from the department of Electrical and Computer Engineering of National Technical University of Athens, Greece, in June 1997, the M.S. degree in Electrical Engineering from Stanford University, California, in January 1999, and the Ph.D. degree in Electrical Engineering from Stanford University in January 2003. Konstantinos models, designs, and analyzes the performance of computer networks, sensor and mobile systems, and the web. He is particularly interested in inventing methods and algorithms to efficiently solve problems related to such systems. Konstantinos has been a Stanford Graduate Fellow throughout his graduate studies. He has received the best-student National Technical University of Athens award for graduating first in his class. |
| Presented On: | Friday, March 4, 2005 |
| Videotape: | Click to View the Streaming Quicktime Presentation This presentation requires the free Apple QuickTime Player which can be downloaded from the following link: www.apple.com/quicktime/download |
