Modeling & Simulation Focus Area

OBJECTIVE

IMPROVE INTEROPERABILITY OF MODELING AND SIMULATION APPLICATIONS IN THE DISTRIBUTED COMPUTING ENVIRONMENT.

Problem Space

Many current efforts contain largely real time simulations. There are two standards that are currently in wide scale use: Distributed Interactive Simulation (DIS) and the High Level Architecture (HLA -- The HLA has been standardised by the OMG as FDSS (Facility for Distributed Simulation Systems – formal/99-10-05). Most new work is being undertaken using HLA with the capability to incorporate existing DIS simulations. DIS simulations exchange data using a set of defined PDUs (Protocol Data Units) although it also provides some ‘free format’ PDUs which were used to exchange information which was not covered by one of the defined PDUs. HLA federations generate a Federation Object Model (FOM) specific to the simulations incorporated in the particular federation. The FOM tends to be based on a reference FOM, normally the Real Time Platform Reference (RPR) FOM that was produced by the DIS community

Interoperability between DIS or HLA federations is not guaranteed unless DIS PDUs or the RPR FOM is used without change. However, in practice, it is difficult to implement a federation without additions to the RPR FOM and there is no governing body to ensure that modifications are made in a consistent manner. An area that requires addressing in terms of standardisation is in the area of modelling of communications, particularly data links. If maritime, air and land simulations are to work together, data links and communications in general must exchange information in a consistent manner.

A special focus should be put on the FDSS. FDSS, as a standard for the information distribution within military simulators, specifies a dissemination-based paradigm. This corresponds to the determinism in a real world scenario. CORBA is not limited to this particular kind of the information exchange. Therefore CORBA resides on a different logical layer than the FDSS. As a consequence of this, it is possible to realize FDSS on top of CORBA. However, CORBA provides mechanisms, which allow more kinds of information exchange.

Mixed configurations of simulators and actual systems are an important aspect that is difficult to support using the FDSS as currently specified. Since the components – i.e. both the real C2 system and the sensors and actuators – are not based on FDSS, there is a need for standards in this domain.

Statement of Need

Their is a need to capitalize on extant DIS simulations coupled with the framing and development required to exploit HLA/FDSS and to mitigate against migration from DIS to HLS/FDSS. However, the need to run and manage real-time simulations provides a powerful requirement for migration to HLS/FDSS. Therefore, there exists an important requirement to be able to migrate existing solutions into real-time distributed HLA federations that are based on world wide web accessible functionality. Thus, the functionality of HLS/FDSS must be evolved to be MDA-based and accessible on the World Wide Web.

Relation to other OMG activity

Modeling and Simulation are of interest in multiple other OMG components including the Business Enterprise Integration DTF, Geospatial and Imagery Value Added Services (GIVAS) DTF, Manufacturing Technology & Industrial Systems DTF, Software-Based Communications DTF, Life Sciences Research DTF, Space DTF, Realtime, Embedded and Specialized Systems PTF, and Model Integrated Computing PSIG. Further, OMG is one of the founding partners of the Web Enabled Modeling and Simulation Partnership (WebSim), information about which can be found at http://www.websim.nethttp://www.websim.net.

C4I DTF Actions

At the meeting in Montreal in September, 2004, the C4I DTF will host a meeting of interested parties to discuss the founding of a SIG for Modeling and Simulation. In the meantime, the C4I DTF is serving as the focal point for modeling and simulation in the OMG for the WebSim Partnership and as the focal point for coordination of Modeling and Simulation activities within the OMG.