Colloquium Speaker

Sanjay Madria, Department of Computer Science, University of Missouri-Rolla
Dynamic Data Replication for Improving Data Accessibility in Ad hoc Networks
Date: Thursday, March 30, 2006
Time: 11:00 AM
Place: Gould-Simpson, Room 906
Refreshments will be served on the 9th floor "atrium" of Gould-Simpson at 10:45AM


In ad hoc networks, due to frequent network partition, data accessibility is lower than that in conventional fixed networks. This problem can be solved by replicating data items on mobile hosts. However, the movement of nodes, limited storage space and frequent disconnections limit the availability.

In this talk, I will discuss three dynamic replica allocation methods by taking into account the read/write patterns at mobile hosts for each data item, the status of the network connection, topology and by considering aperiodic updates and integrating user profiles of mobile users' schedules. These methods allow dynamic relocation of replicas to maintain availability.

I will discuss the performance evaluation of our proposed methods and show their comparison using extensive simulation experiments based on parameters such as write frequency, relocation period, data accessibility, radio communication range, limited memory, among others.


Sanjay Madria received his Ph.D. in Computer Science from Indian Institute of Technology, Delhi, India in 1995. He is an Assistant Professor, Department of Computer Science, at University of Missouri-Rolla, USA. Earlier he was Visiting Assistant Professor in the Department of Computer Science, Purdue University, West Lafayette, USA. He has published more than 100 Journal and conference papers in the areas of web data warehousing, mobile databases, and nested transaction management and performance issues. He guest edited WWW Journal and Data and Knowledge Engineering Sp. Issues on Web data management and Data warehousing. He has co-authored a book "Web Data Management: A Warehouse Approach, published by Springer-verlag. He served as Program Co-chair for ECWEB 00&01 conferences held, UK and Germany. He is serving as PC member of various database conferences (ICDE'07, DASFAA'07 - area chair), co-chair of XSDM'06 and reviewer for many reputed database journals published by ACM, IEEE and Springer among others. His research is supported by grants from NSF, DOE, UM research board and from industry. He is IEEE Senior Member.