HLA-based adaptive distributed simulation of wireless mobile systems

Wireless networks\´ models differ from wired ones at least in the innovative dynamic effects of host-mobility and open-broadcast nature of the wireless medium. Topology changes due to simulated hosts\´ mobility map on causality effects in the "areas of influence" of each mobile device. The analysis of wireless networks of interest today may include a potentially high number of simulated hosts, resulting in performance and scalability problems for discrete-event sequential simulation tools and methods, on a single physical execution unit (PEU). In a distributed simulation, the main bottleneck becomes the communication and synchronization required to maintain the causality constrains between distributed model components. We propose an HLA-based, dynamic mechanism for the runtime management and allocation of model entities in a distributed simulation of wireless networks models, over a cluster of PEUs. By adopting a runtime evaluation of causal bindings between model entities we map the causal effects of virtual topology changes to dynamic migration of data structures. Preliminary results demonstrate that the prototype heuristics lead to a reduction in the percentage of external communication between the PEUs, limited overheads and performance enhancements for a worst-case scenario.