Controller-switch assignment in 5G networks

Explosive growth in both quantity and quality of services and the development trends in 5G networks indicates that multiple distributed software defined network (SDN) controllers are of increasing importance from both network performance and reliability perspectives. Although SDN was first considered with a logically centralized controller approach, due to delay, reliability, and scalability challenges, moving towards multiple distributed controllers is inevitable. In the distributed controlling scheme, an assignment that associates a controller to each switch is required. Moreover, the number of required SDN controllers and even their locations have to be determined. In this paper, two controller-switch assignment algorithms for static and dynamic scenarios are proposed. The proposed algorithms have the advantage of fast implementation. It is shown by simulations that the proposed assignments outperform recent algorithms in terms of the number of active controllers.