Time management in hierarchical federation using RTI-RTI interoperation

High Level Architecture (HLA) provides interoperation of federates, and hierarchical federation was proposed to extend interoperability to the federation level. In a hierarchical federation, several federations make a hierarchical structure using proxies which represent the behavior of the federations. Time synchronization of federates is essential for interoperation and should be accomplished in hierarchical federation. Previous research studies have suggested a time synchronization algorithm based on LITS (Least Incoming Time Stamp) but a deadlock problem remains in some cases. This paper proposes time management in hierarchical federation. We propose time synchronization algorithm to solve the deadlock problem and stipulates the time states of the proxy for representing federation. A proxy model is constructed based on the proposed algorithm and the algorithm is verified to work correctly in hierarchical federation.