Flexible Topology Description Language for Simulation Programs

The article proposes a language for the description of model topologies in discrete event simulators. The language contains an efficient way to create parametrized, flexible topologies. The language has been implemented as part of the OMNeT++ simulator. In most simulators, the support for defining the topology of the model can be improved upon. For this task, simulators either (1) do not provide explicit support, or (2) only fixed topologies are supported, or (3) flexible topologies require programming. The solution proposed and implemented in OMNeT++ uses a description language with a powerful combination of simple constructs (multiple connections, conditional connections etc.) to allow parametrized description of regular structures. Parametrized structures that have been previously defined in the description language can also be created dynamically, during a simulation run. This feature eliminates the need for several independent runs if one is asking questions like how changes in model topology affect some performance measure.