A causality based time management mechanism for federated simulation

One of the six categories of management services provided in the Run Time Infrastructure (RTI) to federated simulations is time management. Currently, it provides only two message ordering policies, that is, time stamp ordering and receipt ordering. Temporal anomalies occurring during the execution of federation due to the heterogeneous latencies in the communication network are not handled in receipt ordering. While time stamp ordering eliminates the temporal anomalies entirely, it incurs great communication latency, and huge bandwidth requirement. The paper presents a novel time management mechanism which provides a less costly message ordering service, namely causal ordering, to federates. It does not require the specification of lookahead and allows federates that do not require stringent message ordering properties to achieve much more efficient execution. A series of experiments has been carried out to benchmark the performance of this new time management mechanism and the results show that it includes a slight overhead compared to the receipt ordering mechanism but achieves significant performance improvement over the time stamp ordering mechanism