A wireless control plane for deploying SDN in data center networks

As a promising technology for newly emerging computing paradigms, like edge computing and Internet of Things (IoT), Software Defined Networking (SDN) has attracted much attention since 2008. SDN enables centralized network management, mobility supporting, security enhancement and quality of service promotion through separating control and data flows. Data centers (DCs) are treated as an ideal deploying scenarios for SDN since they are usually owned or maintained by single entities. Therefore, many newly constructed DC Networks (DCNs) adopt SDN paradigm to enable flexible and reliable network service. However, applying SDN to already-running DCs is not straightforward since it is very hard for us to deploy SDN without disrupting existing network service or introducing complex wiring. In this paper, a wireless control plane for DCN is put forward based on introducing 60GHz wireless links into DCs to enable incremental deployment of SDN in the DCs. A spanning tree algorithm for constructing the control plane is presented which can efficiently connect racks without incurring high cost. Moreover, to reduce the transmission delay in the control plane, a betweenness centrality-based controller placement method is presented. Compared with traditional wire-only methods, our wireless solution can achieve higher performance with low cost. To evaluate the performance of our control plane, a series of simulation experiments have been conducted on NS3. Experimental results have shown that the proposed control plane could efficiently reduce the one-way delay as well as the completion time of the control flows.