Flexible Multi-Domain IoT Architecture for Smart Cities

Smart city infrastructures are evolving from centralized cloud systems to distributed Cyber-Physical Systems of Systems (CPSoS), requiring integration across heterogeneous administrative domains. This work presents a flexible, modular, multi-domain architecture for automated orchestration and management of IoT services across heterogeneous environments. It relies on a recursive federation model, where autonomous local domains manage their own resources while higher-level components coordinate cross-domain operations. Interoperability is achieved through standardized interfaces using TM Forum Open APIs and ETSI NGSI-LD, while a Secure Integration Fabric enables secure, policy-based coordination across public and private domains. The architecture is validated in a real-world Smart Waste Management pilot, demonstrating support for flexible workflows, cross-platform collaboration, real-time decision-making, and avoidance of vendor lock-in. Experimental results show that dynamic, context-driven service orchestration improves scalability, interoperability, and resource efficiency compared to static deployments.