Ruminations on the implications of multi-resolution modeling on DIS/HLA

With the advent of standardization efforts such as the High Level Architecture (HLA) and Distributed Interactive Simulation (DIS), inter-operability of military simulation models has emerged as the chief design requirement. By enforcing strict conformance to the DIS and/or HLA, the Defense Modeling and Simulation Office (DMSO) has so far been able to “mix-and-match” different simulation models and frameworks to satisfy the military´s simulation needs. However, by linking different legacy simulations (simulations previously designed to operate independently) together, the simulation now has to correctly handle multiple levels of detail in the interacting simulation entities. In addition, a given entity itself can be represented in different ways each with a different level of detail (also referred to as resolution or fidelity). A natural question to ask in this situation is why does the model require different resolutions? Why isn´t one level of resolution sufficient to address all the needs of the simulation? There is no simple answer to this question. Depending on the model, what it is used for, and what it is interacting with, it may require several different resolutions. One justification for the need for different resolutions is the way humans think and comprehend information. In general, humans think and reason at different levels of detail and therefore require models to reflect their chosen resolutions. By embedding their knowledge into simulation models, simulation designers try and build a virtual world that mimics the real world. We survey and review previous attempts at multi-resolution modeling and discuss its implications for the DIS, HLA, and parallel discrete-event simulation (PDES) communities