SDN Core for Mobility between Cognitive Radio and 802.11 Networks

In this paper, we implement an Open Flow based fully functional 802.1X access network and an IP based cognitive access network which are interconnected as edge networks to our SDN core. We realize seamless mobility in the WLAN domain and mobility between WLAN and Cognitive networks for the clients with dual band support. The pre-installed flows on the backbone aggregate traffic from access networks and forward in-between. We implement an access control mechanism integrated with DHCP, to prevent unregistered users accessing the network. This work seems to be the first realization of integration of an IP based cognitive network and Open Flow enabled fully functional WLAN into SDN core. Our results elaborate throughput measurements and an extensive description of TCP characteristics based on tcpdump traces in-between WLAN and cognitive clients. The results reveal, that the delay is within the limits of most delay sensitive applications, such as VoIP and gaming.