The Joint Forces Command (JFCOM) Experimentation Directorate (J9)'s recent Joint Urban Operations (JUO)experiments have demonstrated the viability of Forces Modeling and Simulation in a distributed environment. TheJSAF application suite, combined with the RTI-s communications system, provides the ability to run distributedsimulations with sites located across the United States, from Norfolk, Virginia to Maui, Hawaii. Interest-awarerouters are essential for communications in the large, distributed environments, and the current RTI-s frameworkprovides such routers connected in a straightforward tree topology. This approach is successful for small to mediumsized simulations, but faces a number of significant limitations for very large simulations over high-latency, widearea networks. In particular, traffic is forced through a single site, drastically increasing distances messages musttravel to sites not near the top of the tree. Aggregate bandwidth is limited to the bandwidth of the site hosting thetop router, and failures in the upper levels of the router tree can result in widespread communications lossesthroughout the system.To resolve these issues, this work extends the RTI-s software router infrastructure to accommodate moresophisticated, general router topologies, including both the existing tree framework and a new generalization of thefully connected mesh topologies used in the SF Express ModSAF simulations of 100K fully interacting vehicles.The new software router objects incorporate the scalable features of the SF Express design, while optionally usinglow-level RTI-s objects to perform actual site-to-site communications. The (substantial) limitations of the originalmesh router formalism have been eliminated, allowing fully dynamic operations. The mesh topology capabilitiesallow aggregate bandwidth and site-to-site latencies to match actual network performance. The heavy resource load atthe root node can now be distributed across routers at the participating sites.
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