The Command and Control (C2) Community has a set of systems, standards and protocols that it uses to solve its main interoperability challenge which is to communicate a consistent common operational picture (COP) of the real battle space. Similarly, the modeling and simulation (M&S) community has evolved its own standards and protocols to deal with its main interoperability challenge which is to accurately model and simulate the synthetic battle space using one or more systems. However, as we move towards a system of system environment where live, virtual and constructive (LVC) systems are connected and the line between real and simulated entities is purposefully obscured, we are facing a new set of system of system interoperability challenges that cut across communities. In this new environment where information sharing is key, standardized metadata takes prevalence over standardized interfaces, which means that we need to look at standards as a set of interoperability enablers that must be coherently organized in a "system of standards."

In this paper, we present the coalition battle management services (CBMS) as a system of system approach to dealing with system of system interoperability in general and C2 to simulation interoperability in particular. We distinguish between the CBMS approach, which is based on the observation that an interoperability system must be developed following interoperability requirements; the CBMS architecture based on the design pattern of the World Wide Web (WWW); and the CBMS implementation based on standards and open source tools. We describe how systems can use CBMS in support of interoperability and present a CBMS use case of C2 to simulation interoperability in a coalition environment using the Coalition Battle Management Language (C-BML) and the Military Scenario Definition Language (MSDL). Finally, we discuss the implications of CBMS on M&S standards and system of system interoperability.