Assurance networks are designed to realize trustable Internet-Of-Things including terminal devices/infrastructure service applications for new generation networks. This paper proposes a unified design model for assurance networks and demonstrates the model, methodology and its application to mobile ad hoc networks. In the unified design model, in order to realize the assurance networks, an overall network is partitioned into sub networks and real-time self-organized control functions are incorporated into each sub network for resilience to dynamic change, faults possibly causing failure and attacks to security. In the application of the proposed unified design model to mobile ad hoc networks, a real-time self-organizing autonomous clustering is presented. The simulation experimental results show that the presented autonomous clustering is resilient to a diversity of node mobility and its variation.