The first phase of the C-5 Distributed Mission Training (DMT) contract has been successfully developed and delivered to the Air Force Air Mobility Command. It has met its goal of using the High Level Architecture (HLA) to link two existing C-5 training simulators to demonstrate DMT technology capable of training missions such as formation airdrop and air refueling.

As this is one of the first real-time manned simulation programs delivered using HLA, it has been closely watched as a demonstrator of HLA's ability to serve the needs of training simulation and real-time simulation in general. To this end, the contract funded an effort to perform objective tests to analyze HLA Run-Time Infrastructure (RTI) performance in a real-time environment.

This paper provides a brief introduction to the C-5 DMT system architecture. The paper's major emphasis is on the purpose and results of the analysis tests that were performed on the C-5 DMT simulators. The four tests were network bandwidth utilization, RTI latency, processor utilization, and entity position error due to dead reckoning. All tests were run with a varying number of aircraft entities to show the trends that result from scaling to larger exercises. Use of the trends to predict system performance in larger DMT exercises is discussed. Also described is a means for simulating the effects of a long-haul network by injecting statistically random delay in the local area HLA network.

The overall conclusion from this project, verified by the analysis tests, is that real-time manned simulation is possible using the current HLA RTI under favorable conditions, but only for federations of up to 10's of entities. Federations of 100's or 1000's of entities will require an RTI with a corresponding order of magnitude increase in performance and capability.

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Steve Monson