Airpower Mission Training through Distributed Simulation (MTDS) is becoming a crucial capability for Air Forces to satisfy their coalition collective training needs. In these MTDS capabilities simulation assets from different security domains must be able to interoperate effectively and efficiently within a single training exercise. Cross domain solutions (CDS) are a common to tackle such security issues in the C4ISR domain. However CDS specifically designed for MTDS assets are rare, though MTDS imposes unique requirements on such solutions. The returning key challenges are: to what extend can simulation data be degraded while not compromising training value and reducing the risk of unwanted information leakage into another domain to an acceptable minimum.

Currently, the Royal Netherlands Airspace Centre NLR is developing the theoretical and practical foundations for a cross domain solution to support the Royal Netherlands Air Force (RNLAF) in their needs to interoperate national classified simulation training capabilities of various levels within a single distributed mission training environment, as well as in joint mission training with NATO coalition partners. For this purpose NLR is actively participating in NATO MSG 165 task group on the Incremental Implementation of MTDS for Joint and Combined Air Operations.

The paper will introduce a conceptual framework that provides the fundamental and general applicable CDS terminology, semantics, concepts and principles related to Airpower MTDS. The framework facilitates the communication, understanding and implementation of CDS within the simulation domain. It provides the core foundations upon which NLR’s secure simulation interoperability testbed rest, which will be outlined next in this paper. Finally, several possible CDS implementation designs and the lessons learned from their experimentational evaluation will be discussed in the third part. In here the focus lays on the real-time simulation performance impact, level of training fidelity and value, and information leakage risks in Airpower MTDS exercises.