4 research outputs found
Advanced Message Routing for Scalable Distributed Simulations
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. The
JSAF application suite, combined with the RTI-s communications system, provides the ability to run distributed
simulations with sites located across the United States, from Norfolk, Virginia to Maui, Hawaii. Interest-aware
routers are essential for communications in the large, distributed environments, and the current RTI-s framework
provides such routers connected in a straightforward tree topology. This approach is successful for small to medium
sized simulations, but faces a number of significant limitations for very large simulations over high-latency, wide
area networks. In particular, traffic is forced through a single site, drastically increasing distances messages must
travel to sites not near the top of the tree. Aggregate bandwidth is limited to the bandwidth of the site hosting the
top router, and failures in the upper levels of the router tree can result in widespread communications losses
throughout the system.
To resolve these issues, this work extends the RTI-s software router infrastructure to accommodate more
sophisticated, general router topologies, including both the existing tree framework and a new generalization of the
fully 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 using
low-level RTI-s objects to perform actual site-to-site communications. The (substantial) limitations of the original
mesh router formalism have been eliminated, allowing fully dynamic operations. The mesh topology capabilities
allow aggregate bandwidth and site-to-site latencies to match actual network performance. The heavy resource load at
the root node can now be distributed across routers at the participating sites
Distributed and Interactive Simulations Operating at Large Scale for Transcontinental Experimentation
This paper addresses the use of emerging technologies to respond to the increasing needs for larger and more sophisticated agent-based simulations of urban areas. The U.S. Joint Forces Command has found it useful to seek out and apply technologies largely developed for academic research in the physical sciences. The use of these techniques in transcontinentally distributed, interactive experimentation has been shown to be effective and stable and the analyses of the data find parallels in the behavioral sciences. The authors relate their decade and a half experience in implementing high performance computing hardware, software and user inter-face architectures. These have enabled heretofore unachievable results. They focus on three advances: the use of general purpose graphics processing units as computing accelerators, the efficiencies derived from implementing interest managed routers in distributed systems, and the benefits of effective data management for the voluminous information
Simulation Evaluation of the Combat Value of a Standoff Precision Airdrop Capability
This project is a simulation evaluation of the developmental standoff precision airdrop (SOPAD) capability. SOPAD is a new technology under consideration to deliver supplies to forward-deployed units using either a semi-rigid wing or a guided parafoil. These delivery systems allow airdrop of supplies from altitudes of 25,000 feet and distances 25 miles from the delivery point. Using global positioning system guidance, on board navigational computers, and automatic steering mechanisms, the delivery system flies to the target following a designated flight plan. The concept includes delivering supplies to remote and potentially hostile areas without endangering the supply aircraft. In addition, supplies can be delivered to multiple locations from a single aircraft. The Air Force\u27s THUNDER model was used to simulate the SOPAD capability and observe the impact in the simulated combat environment. The scenario places a light infantry brigade in a position where supply by ground is prohibited due to terrain limitations and it must hold its position until relief forces are available. The unit must fight for a one-week period being resupplied only through airdrop. The results of the simulation are measured through aircraft attrition, unit strength, forward line of troops movement, and the supplies delivered to the unit
Scalable RTI-Based Parallel Simulation of Networks
©2003 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.Presented at the Seventeenth Workshop on Parallel and Distributed Simulation (PADS 03), 2003Federated simulation interfaces such as the High Level
Architecture (HLA) were designed for interoperability,
and as such are not traditionally associated with high performance
computing. In this paper, we present results
of a case study examining the use of federated simulations
using runtime infrastructure (RTI) software to realize
large-scale parallel network simulators. We examine the
performance of two different federated network
simulators, and describe RTI performance optimizations
that were used to achieve efficient execution. We show
that RTI-based parallel simulations can scale extremely
well and achieve very high speedup. Our experiments
yielded more than 80-fold scaled speedup in simulating
large TCP/IP networks, demonstrating performance of up
to 6 million simulated packet transmissions per second on
a Linux cluster. Networks containing up to two million
network nodes (routers and end systems) were simulated