TUTW

Temporal Uncertainty Time Warp is an implementation of the Time Warp distributed algorithm especially tuned to networked distributed simulations. It adopts an aggressive cancellation technique which tends to conserve bandwidth during rollbacks. Only a single undo event, provided of a time horizon, is sent to partner Logical Processes (LPs) asking them to cancel previous incorrect computation. TUTW adopts an event model where the occurrence of an event can be specified by a time interval (temporal uncertainty TU) instead of a classical "precise" timestamp. TU increases the concurrency degree of events. Causality relations between concurrent events are ensured by logical clocks (e.g. Lamport clocks). TU enables the control engine to relax in part the synchronization constraints so as to improve the simulation performance. It has been experimentally observed that the use of a limited amount of TU, which in general is application dependent, is able to speedup the distributed simulator without necessarily compromising the accuracy of statistics. Current version of TUTW is implemented in Java.