Abstract. The High Level Architecture promotes simulation interoperability and reusability, making it an ideal candidate to model large-scale systems. However, a large-scale simulation running in a distributed environment is often affected by the imbalance of load level at different computing hosts. Migrating processes from heavily-loaded hosts to less-loaded hosts can overcome this shortcoming. We have previously developed a SimKernel framework to execute HLA-based simulations in the Grid environment with migration support as a prominent design feature. In this paper, we will introduce a transparent migration protocol for SimKernel-based federates that minimizes migration overhead.