A novel min-cost Qos routing algorithm for SDN-based wireless mesh network

Software Defined Networking (SDN) is a novel architecture, which is suitable for managing and controlling networks in a centralized way with global view, and can provide more effective and fine-grained resource allocation for routing management. Compared with traditional wireless mesh network (WMN), the SDN-based WMN (SDN-WMN) can guarantee the Quality of Service (QoS) more effectively. In this paper, we propose a novel min-cost QoS routing algorithm (MCQRA) for SDN-WMN to find out the path with minimum cost more efficiently, meeting the demands of QoS (e.g. bandwidth, delay and packet loss). To solve the NP-hardness problem, Lagrange relaxation method first is utilized to optimize multi-constraints problem. In the algorithm, a new dynamic step size is presented in the weight factor, which changes the corresponding proportion in link weight and influences by effectively feedback of the historical search results. And then the heuristic is utilized weight to gradually iterate, and quickly converge to discover optimal path. An out-of-band mode is employed for SDN-WMN performance simulations. Simulation results indicate that the proposed approach can obtain better performance than conventional routing scheme in terms of QoS satisfaction ratio and bandwidth utilization, with reduced overhead.