Logically Centralized-Physically Distributed Software Defined Network Controller Architecture

Due to the large usage of internet, our environment is transformed into digital society, in which everything is connected together and can be accessed from anywhere. This is the Internet of things (IoT), which refers to the usage of intelligently connected devices and systems. These devices usually collect their data from sensors and actuators in machines and other physical objects. This makes Wireless Sensor Network (WSN) a subset of an Internet of things (IoT) topology, and hence it acts like a bridge that connects the real world to the digital world. So it is important to find a flexible network that can support this development rather than our traditional network. But WSN has a major problem, which is the highest energy consumption of nodes which reduces network lifetime. So we propose to use Software Defined Network (SDN) as a solution for this problem, as SDN's main feature consists of separating between data plane and control plane. This usually transforms data plane sensor node from forwarding node to dummy devices, which reduces energy consumption and hence prolong network lifetime. SDN usually can be implemented in different architectures. We study different SDN-based WSN management structures, and we accommodate logically centralized-physically distributed controller in a WSN environment. Our simulation test held using Mininet-WIFI simulator indicates that logically centralized-physically distributed controller is the one with higher throughput and less delay in IoT environment compared to other architectures.