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                              | Modeling 
                                  Disruption Tolerant Networks: Fluid Models and 
                                  Mobility Models By  
                                   
                                    Prof. 
                                      Don TowsleyProfessor, 
                                    Department of Computer Science, University 
                                    of Massachusetts    
 
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                              | Date: 
                                  Nov 11, 2008 (Tuesday) |   
                              | Time: 
                                  2:30pm - 3:30pm |   
                              | Venue: 
                                  Rm. 1009, William M.W. Mong Engineering Building, 
                                  CUHK |  Abstract 
                            :  In 
                            this talk we study focus on two aspects of disruption 
                            tolerant networks (DTNs). First we study epidemic 
                            routing and its variations through the use of fluid 
                            models. in many cases these models yield closed-form 
                            expressions for performance metrics such as average 
                            delivery delay and can be easily solved numerically 
                            for other cases. We also show how these models can 
                            be adapted to study DTNs with infrastructure.  Second, 
                            we focus on the problem of modeling node mobility 
                            in a DTN. Specifically, we study traces taken from 
                            UMass DieselNet, a bus-based DTN. The standard model 
                            assumes nodes are homogeneous and represents their 
                            mobility in the form of an aggregate inter-contact 
                            time distribution. We find that simulation of a DTN 
                            using such a model results in lower average delivery 
                            delays. We then present route-level contact models 
                            and show that their use leads to much better delay 
                            predictions.  Biography 
                            :  Don 
                            Towsley received a B.A. degree in physics and a Ph.D. 
                            degree in computer science, both from University of 
                            Texas University. He is currently a Distinguished 
                            University Professor in the Department of Computer 
                            Science at the University of Massachusetts - Amherst, 
                            where he co-directs the Networking Research Laboratory. 
                            Professor Towsley has been a Visiting Scientist at 
                            AT&T Labs - Research, IBM Research, INRIA , Microsoft 
                            Research Cambridge, and the University of Paris 6. 
                             Prof. 
                            Towsley's research interests include network measurement, 
                            modeling, and analysis. He currently serves as Editor-in-Chief 
                            of the IEEE/ACM Transactions on Networking and on 
                            the editorial boards of Journal of the ACM and IEEE 
                            Journal of Selected Areas in Communications. He is 
                            also currently Chair of the IFIP Working Group 7.3 
                            on computer performance measurement, modeling, and 
                            analysis. He has also served on numerous editorial 
                            boards including those of IEEE Transactions on Communications 
                            and Performance Evaluation. He has been active in 
                            the program committees for numerous conferences including 
                            IEEE Infocom, ACM SIGCOMM, ACM SIGMETRICS, and IFIP 
                            Performance conferences for many years, and has served 
                            as Technical Program Co-Chair for ACM SIGMETRICS and 
                            Performance conferences.  Prof. 
                            Towsley has received the 2007 IEEE Koji Kobayashi 
                            Computer and Communications Award , the 2007 ACM SIGMETRICS 
                            Achievement Award, the 1999 IEEE Communications Society 
                            William Bennett Award, and several conference and 
                            workshop best paper awards. He is also the recipient 
                            of the University of Massachusetts Chancellor's Medal 
                            and the Outstanding Research Award from the College 
                            of Natural Science and Mathematics at the University 
                            of Massachusetts. He is one of the founders of the 
                            Computer Performance Foundation. He has twice received 
                            IBM Faculty Fellowship Awards, and is a Fellow of 
                            the IEEE and the ACM.  |