Combining numbers of simulations in a single large exercise requires that the inter-communications architectures (e.g., HLA - High-level Architecture, TENA - Test & Training Enabling Architecture, etc.) that those systems use must also be present in the exercise. When systems that use different inter-communications architectures interact, the interaction must be transmitted between the architectures as a lossless communication. To many, this will seem a trivial consideration, given the commonplace and broad experience with communication between systems using the internet. However unexpected it may sound, HLA interactions will not be understood by simulation systems using TENA unless additional effort (typically, adding a gateway) is made supporting appropriate translation.

This small example symbolizes a broader but closely-related problem set that has impacted large simulation exercises for years. The Live-Virtual-Constructive Architecture Roadmap (LVCAR) Study was chartered to develop a future vision and supporting strategy for achieving significant interoperability improvements in LVC simulation environments, reducing the problem set to the trivial challenge that many internet-experienced consumers expect. The study addressed three main areas of concern; the desired future integrating architecture(s), the desired business model(s), and the manner in which standards should be evolved and compliance evaluated. For each area, the study provided near-, mid-, and long-term recommendations that together constitute a roadmap to guide the evolution of LVC architecture development to achieve a more seamless environment.

This paper reviews the study's assumptions, fundamental precepts, and conclusions and presents them as integral parts of a plan now being carried out. The paper also provides a view into the reasoning behind the study's recommendations and concludes with a description of the future for simulation architectures.