Hybrid Dual Stack Control Plane Design for Resilient Software Defined WSANs

Software-Defined Networking (SDN) represents a disruptive paradigm with significant potential to enhance the Internet of Things (IoT) wireless domain. However, the design and implementation guidelines for this advanced framework remain an open challenge. While adaptation of centralised protocols for low-power wireless sensor and actuator networks (WSANs) led to basic Software-Defined WSAN (SDWSAN) architectures, this approach exhibits notable limitations, particularly in large-scale and dynamic scenarios. For instance, the centralised SDN controller does not only introduce a Single Point of Failure (SPoF) for the managed network but also generates substantial overhead due to control protocols and messages (often inspired by the OpenFlow standard), which can significantly degrade Data Plane (DP) performance. This paper addresses these challenges by proposing Software-Defined Hybrid Dual Stack (SOHS), a novel hybrid architecture that integrates the distributed nature of traditional WSANs within a centralised SDN management framework. By harmonising these paradigms, SOHS optimises scalability and adaptability. Furthermore, we conduct a comprehensive comparison of the proposed hybrid dual-stack control plane architecture against existing alternatives (specifically SDN-WISE, IT-SDN, and uSDN frameworks) evaluating key metrics such as availability, overhead, and end-to-end delay. Our analysis demonstrates that SOHS achieves significant performance improvements, particularly in large-scale networks with dynamic topology changes.