Laguna Beach: HLA on Baywatch? Marco Brassé Wim Huiskamp Hans Jense Leo Breebaart TNO Physics and Electronics Laboratory. P.O.Box 96864 2509 JG The Hague, The Netherlands {brasse | huiskamp | jense | breebaart}@fel.tno.nl Keywords: HLA, Legacy Code, Federate Development, RTI Middleware, Code Generation ABSTRACT: Laguna Beach is a legacy stand-alone flight simulator, developed for demonstration purposes by Sili- con Graphics, Inc. The Simulation group at TNO–FEL was able to successfully, and with only a modest amount of effort, convert this legacy application into an interoperable, HLA-compliant multi-aircraft federation. This rapid mi- gration was achieved by using the RCI (Runtime Communication Infrastructure), developed by TNO–FEL in the SIMULTAAN project. The RCI is a code-generating middleware layer that abstracts simulation applications from the underlying interoperability standards (such as HLA or DIS). In the case of HLA, the RCI takes HLA object models as input, and from these the RCI code generator produces the necessary RTI communication and administrative frame- work. The first phase of the Laguna conversion process consisted of a FEDEP-based design cycle focused on analysing the code and data structures, identifying the required federates, and mapping the entities and state representations to HLA objects and interactions. The second phase consisted of using the RCI to generate the federation framework from the Laguna SOM created in the first phase. In the third phase the original application was then attached to this framework. TNO’s experiences with the Laguna Beach conversion show that a middleware-based approach to simu- lator migration is a highly successful one that can significantly decrease the time and effort necessary to achieve HLA-compliance for legacy simulators. 1. Introduction Of considerable interest to various user communities in the simulation world is the question of how well HLA supports the migration and re-use of existing simulators that communicate using a different communication standard, or that may not even be interoperable at all ([4], [5]). This paper describes a project in which Laguna Beach, a legacy stand-alone flight simulator, was successfully, and with only a modest amount of effort, converted into an interoperable, HLA-compliant multi-aircraft federa- tion. This conversion made use of the RCI (Runtime Communication Infrastructure), a code-generating mid- dleware layer that abstracts simulation applications from the underlying interoperability standards. The RCI concept was developed by TNO-FEL in the SIMULTAAN project [1]. 2. The SIMULTAAN Project and the RCI SIMULTAAN is a 2.5 years project which brings together knowledge and experience in the area of simulators and distributed simulation from universities, research insti- tutes and industry in The Netherlands. SIMULTAAN aims at the development of a generic simulator architecture, facilitating the interoperability of a wide range of simulators, including manned mock- ups of vehicles, high-fidelity flight simulators and un- manned simulators. In SIMULTAAN, each federate consists of a number of components such as a visual system, a motion system, a dynamic model, and a mock-up server. Two types of