Placing controllers in software-defined wireless mesh networks

Abstract

Software Defined Networks (SDN) are a novel class of networking solutions in which the traditional paradigm of distributed networking has been replaced with centralized networking approach in which a central controller or a group of controllers make the optimal decisions and the nodes become merely forwarding switches. Similar to the wired domain, Software-Defined Wireless Mesh Networks (SDWMNs) SDWMNs leverage the power of centralized decision making to reap the benefits of sophisticated mathematical optimization models in wireless networks. However, there are several issues including controller placement that remain to be addressed for SDWMNs compared to their wired counterparts. The controller placement problem has received significant attention for wired networks, but is an open research area for software-defined mesh networks. The problem is harder because of the wireless channel including interference (collisions, retransmissions, bit errors etc.) and especially since the wireless channel is used for control messages as well. In this paper, we propose an efficient algorithm for the problem of optimal controller placement in SDWMNs. The proposed algorithm efficiently places N controllers at optimal positions in the network so as to minimize interference compared to random deployment of controllers. Simulation results show the better performance of our solution with random deployment.