Hierarchical federations: an architecture for information hiding

In a distributed simulation, simulation components of various types are executed at geographically different locations, forming a simulation federation to create a common virtual environment. Under the High Level Architecture (HLA), information that will be produced and consumed by a simulation component is defined in its object model, and how that information is produced and consumed is well encapsulated inside the simulation component's implementation. However in the current implementation of the HLA's Runtime Infrastructure (RTI), information hiding between groups of simulation components in a simulation federation is not addressed. The authors discuss how hierarchical federation architectures can be used to tackle this problem. The hierarchical federation architecture adopted in the paper differs from the existing architectures in that it is based on a hybrid approach for interoperability between simulation federations. To demonstrate information hiding using the architecture, a distributed semiconductor supply-chain simulation is also described.