A simulation based study to identify optimal number of controllers for multi-application scenarios in Software Defined Wireless Sensor Network (SDWSN).

Software Defined Network (SDN) is an effective way of implementing modularity based on abstraction for complex networking principles. SDN has shown its positive impact on various types of networks and the use of SDN in MEMS (Microelectronic Mechanicals Systems) based network also known as Wireless Sensor Network (WSN), helps to alleviate WSN challenges such as less power consumption and better throughput. So far, study on optimal number of controllers and their impact on network parameters remain untouched. In this paper, we follow a simulation-based approach to identify the optimal number of SDN controllers required to manage nodes in WSN. We consider a network of nodes as well as a WSN sink and randomly assign multiple nodes with SDN functionality. We varied the number of controllers and their location for multi-application scenarios. Results show that a) The optimal number of controllers are dependent on the number of applications and nature of application assigned to WSN, b) Presence of SDN controllers increases network lifetime in terms of the amount of residual energy left on the nodes, and c) Selecting appropriate path and assigning routes to WSN nodes by SDN controller increases the overall application throughput.