Title:    JiST: Java in Simulation Time
            for Scalable Simulation of Mobile Ad hoc Networks
Speaker:  Rimon Barr <barr@cs.cornell.edu>
Date:     Wednesday, 19 November 2003
Time:     2:30 - 3:30pm
Location: 5130 Upson.

Discrete event simulators are important scientific tools. For
example, research in the areas of wireless ad hoc and sensor
networks is fundamentally dependent on simulators. Yet, existing
tools for modeling the behaviour of such networks are often
unsatisfactory, because they severely limit the possible scale,
level of detail or duration of the simulation results.

In this talk, I will describe a new approach for constructing
discrete event simulators that leverages virtual machines and
combines the traditional systems-based and language-based
approaches to simulator construction. JiST, for Java in
Simulation Time, is a simulation engine that embodies this new
technique. It embeds simulation execution semantics directly into
the Java virtual machine. I will explain how the basic system
works and then demonstrate that this approach is not only
surprisingly efficent, but also flexible. Finally, I will
illustrate a practical application of JiST through SWANS, a
Scalable Wireless Ad hoc Network Simulator that runs atop JiST.
SWANS can simulate wireless networks of 100,000 nodes and up,
more than an order of magnitude larger than what existing
simulators can achieve on equivalent hardware.