Computer Science Colloquium

This talk presents proposed solutions in order to manage the stability of mobile multi-hop radio networks, also called ad hoc networks, which play a critical role in places where a wired backbone is neither available nor economically feasible and thus deployment of such networks becomes necessary. The movement of the nodes constantly changes the topology of the underlying network. Therefore, it becomes necessary to identify certain nodes, called clusterheads, which help on maintaining the topology of the network. Since selecting clusterheads optimally is an NP-hard problem, we propose a distributed Weighted Clustering Algorithm (WCA) which takes into consideration several physical parameters such as the number of nodes a clusterhead can handle ideally, transmission power, mobility, and battery power of the nodes. The execution of WCA is delayed as long as possible and is invoked adaptively such that the communication and computation costs are reduced. WCA also ensures connectedness and tries to uniformly distribute the loads of the nodes. Once the clustering is achieved, essential network operations such as routing, need to be managed. We define a new protocol called B-protocol based on the fact that efficient management of network resources can be obtained by deploying only a small subset of the network nodes, called B-nodes. Routing is achieved via links, called B-links, which are also a small subset of the total number of links in the network. Since a route is not guaranteed to last till the end of the session, we estimate the expected life of a route based on the relative mobility of nodes and their mobility pattern so that alternative routes can be found ahead of time in order to avoid any possible communication disruption.

Damla Turgut is currently a Ph.D. candidate and an Assistant Instructor in the Department of Computer Science and Engineering at University of Texas at Arlington (UTA). She received her B.S. and M.S. degrees in Computer Science and Engineering from UTA. She is a member of the Center for Research in Wireless Mobility and Networking (CReWMaN). Her current research interests include mobile ad hoc networks, wireless networking, mobile computing, and object-oriented databases. She is a recipient of the Texas Telecommunication and Engineering Consortium (TxTEC) fellowship. She received Outstanding Teaching Award presented by the Department of Computer Science and Engineering in 2002. She is also a member of Upsilon Pi Epsilon (UPE) Computing Honor Society.