This paper presents the CONCEPT.IO arena – an open-source simulation and demonstration arena architecture designed for academic CONOPs (Concept of Operations) experimentation in system of systems involving robotics, models, and digital twins. The platform integrates mapping, MQTT (Message Qu-based communication, and a multi-modal interaction to replicate both virtual and physical environments. Such integration enables testing and validation of operational concepts, providing an educational resource for student-led projects. Using real-time logging, sensor-driven digital twins, and controlled simulation scenarios, the arena enables to verify that designed CONOPs are both applicable and effective within the intended context. This paper further discusses the challenges and benefits of using open-source elements to bridge theoretical instruction and practical application, ultimately advancing academic research in systems engineering and system of systems.