COLLOQUIUM Department of Computer Science and Engineering University of South Carolina A Software Engineering Perspective on Context-Awareness in Ad Hoc Mobile Networks Christine Julien Department of Computer Science and Engineering Washington University Date: February 6, 2004 (Friday) Time: 3:30-4:30PM Place: Swearingen 1A03 (Faculty Lounge) Abstract Ad hoc networks form opportunistically and change rapidly in response to the movement of mobile hosts. These networks present new software engineering challenges, especially given the increasing demand for applications tailored to a wide variety of domains. Applications executing in ad hoc networks need to react continuously and rapidly to changes in operating conditions and must adapt their behavior accordingly. Such applications fall in the category of context-aware computing, a field that has received much recent attention. Much of the current work on context-aware computing is limited to presenting only specific types of context information, e.g., location or time. In addition, current context-aware systems often rely only on information directly available to an application via context sensors on the local host. In this talk, I introduce a novel perspective on context-awareness in which the context includes, in principle, any information available in the ad hoc network but is restricted, in practice, to specific projections of the overall context. I will present the design and implementation of a new middleware model that delivers this notion of context to the application programmer. Specifically, the middleware introduces the ability for particular tasks to operate over dynamically and declaratively specified abstract views of the global context. Despite the fact that interactions among hosts in the underlying network are transient and disconnections are frequent, the middleware continuously maintains the desired contextual information. I also present novel network protocols that provide the context-maintenance required to support the middleware’s implementation. The resulting context-aware middleware eases the software engineering challenges encountered when programming applications for ad hoc mobile environments. Christine Julien is a D.Sc. candidate in Computer Science and Engineering at Washington University in Saint Louis. She holds a Graduate Research Fellowship from the National Science Foundation. Christine received her M.S. in Computer Science in 2003 and her B.S. in 2000, both from Washington University. Her research interests include software engineering for mobile computing, formal methods for distributed systems, and network algorithm design.