Enhancing Simulation Composability and Reuse with Modular FOMs

Simulation composability and reuse have long represented the “Holy Grail” of distributed simulation. The ability to develop simulation components in a way that enables them to be reused as well as the ability to pull together independently developed simulation components have long promised flexibility and cost savings for Department of Defense simulations.

While the High Level Architecture (HLA) has provided an interoperability standard enabling simulation components to work together, seamless simulation component reuse and composability remain elusive goals. A number of challenges to composability have been identified, and one of the major challenges has always been the data exchange model. Davis [1] and Henninger [2] both address improving composability, and both identify data exchange models as an issue. The Live Virtual Constructive Architecture Roadmap (LVCAR) study [2] recommended standardized common object model components as the highest priority investment for the Department of Defense (DoD) simulation roadmap. Efforts such as the Realtime Platform Reference (RPR) and Space Federation Object Model (FOM) seek to standardize a FOM for a particular community. The Medical Modeling and Simulation (MMS) FOM is expected to do the same for the Medical modeling and simulation community. Modular FOMs are a critical component to improve simulation composability and reuse.

This paper addresses how the Joint Evacuation and Transport Simulation (JETS) system architecture is developing a suite of MMS FOM modules, providing the ability to more easily combine simulation components in various configurations or scale to meet current and future medical training needs.

Authors: Dannie Cutts, Damon Curry
Publication: Proceedings of 2020 Winter Simulation Innovation Workshop, 2020-SIW-013, Simulation Interoperability Standards Organization, February 202

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SISO Space Reference FOM – Tools and Testing

The Simulation Interoperability Standards Organization (SISO) Space Reference Federation Object Model (SpaceFOM) version 1.0 is nearing completion. Earlier papers have described the use of the High Level Architecture (HLA) in Space simulation as well as technical aspects of the SpaceFOM. This paper takes a look at different SpaceFOM tools and how they were used during the development and testing of the standard.

The first organizations to develop SpaceFOM-compliant federates for SpaceFOM development and testing were NASA’s Johnson Space Center (JSC), the University of Calabria (UNICAL), and Pitch Technologies.

JSC is one of NASA’s lead centers for human space flight. Much of the core distributed simulation technology development, specifically associated with the SpaceFOM, is done by the NASA Exploration Systems Simulations (NExSyS) team. One of NASA’s principal simulation development tools is the Trick Simulation Environment. NASA’s NExSyS team has been modifying and using Trick and TrickHLA to help develop and test the SpaceFOM.

The System Modeling And Simulation Hub Laboratory (SMASH-Lab) at UNICAL has developed the Simulation Exploration Experience (SEE) HLA Starter kit, that has been used by most SEE teams involved in the distributed simulation of a Moon base. It is particularly useful for the development of federates that are compatible with the SpaceFOM. The HLA Starter Kit is a Java based tool that provides a well-structured framework to simplify the formulation, generation, and execution of SpaceFOM-compliant federates.

Pitch Technologies, a company specializing in distributed simulation, is utilizing a number of their existing HLA tools to support development and testing of the SpaceFOM. In addition to the existing tools, Pitch has developed a few SpaceFOM specific federates: Space Master for managing the initialization, execution and pacing of any SpaceFOM federation; EarthEnvironment, a simple Root Reference Publisher; and Space Monitor, a graphical tool for monitoring reference frames and physical entities.
Early testing of the SpaceFOM was carried out in the SEE university outreach program, initiated in SISO. Students were given a subset of the FOM, that was later extended. Sample federates were developed and frameworks were developed or adapted to the early FOM versions.

As drafts of the standard matured, testing was performed using federates from government, industry, and academia. By mixing federates developed by different teams the standard could be tested with respect to functional correctness, robustness and clarity.

These frameworks and federates have been useful when testing and verifying the design of the standard. In addition to this, they have since formed a starting point for developing SpaceFOM-compliant federations in several projects, for example for NASA, ESA as well as SEE.

Authors: Björn Möller, Andreas Rydell, Edwin Z Crues, Dan Dexter, Alberto Falcone, Afredo Garro
Publication: Proceedings of 2020 Winter Simulation Innovation Workshop, 2020-SIW-027, Simulation Interoperability Standards Organization, February 2020

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An Update on RPR FOM 3

The purpose of the SISO Real-time Platform Reference FOM (RPR FOM) version 3 is to support real-time platform simulation, matching the capabilities of DIS 7. It will also address some issues in RPR FOM 2. RPR FOM 3 is expected to be completed during 2020. Experimental versions of several FOM modules already exist. This paper summarizes the current status, new and improved capabilities and provides some background and rationale.

Some of the key new features relate to IFF (Identification Friend or Foe), Directed Energy Fire, Information Operations and Entity Appearance and Capabilities. For IFF, Mode 5 and Mode S are the most important additions. The IFF module has also been restructured to better represent the different modes of transponders and interrogators as well as the Interactive Mode. The new Information Operations module is very generic, using two interactions with an extendable set of Actions and Statuses and is expected to be useful for operations like electronic warfare, computer network operations, psychological operations, military deception, and operations security. For Entity Appearance and Entity Capabilities, a number of missing properties have been added, based both on DIS 6 and DIS 7.

One of the challenges in the FOM design is the DIS Attribute PDU, the question if or how to bridge the different basic principles for extending an information model in DIS versus HLA. Another challenge is the principles for transferring ownership. The representation of time stamps is yet another challenge, in particular for pure HLA federations, needing to use Time Management. This paper summarizes the approach taken, including pros and cons.

RPR FOM 3 will be a valuable step forward, particularly for use in federations that mix HLA and DIS based systems, as a migration path from DIS to HLA and as a starting point for further extension.

Authors: Björn Möller, Aaron Dubois, René Verhage
Publication: Proceedings of 2020 Winter Simulation Innovation Workshop, 2020-SIW-028, Simulation Interoperability Standards Organization, February 2020

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