Using Soft Real-Time Simulation in a Hybrid Environment for Cyber-Physical Security Experiments

The study of complex systems, either physical or cyber, could be carried out by experimenting with real systems, software simulators or emulators. This paper presents an innovative framework for an experimentation environment that incorporates both physical and cyber systems. The proposed approach uses soft real-time simulation for physical processes (based on Simulink) and an emulation test bed (based on Emulab) for ICT components. The paper also presents two coupling algorithms that couple the simulation time to the system time, in order to achieve soft real-time simulation on a multitasking OS. The main difference between the two algorithms is the size of the critical section that enables concurrent access to a shared resource between emulated and simulated environments. The experimental results show that resource sharing between the two environments is a major concern and future algorithms should also consider a proper analysis of critical sections.