WiFi Network Virtualization to Control the Connectivity of a Target Service

This paper proposes a WiFi network virtualization technique to control the connectivity of a target service. The packet-level delay violation ratio can be reduced even in a congested situation by provisioning dedicated base station (BS) resources (a set of dedicated BSs) to the target service and allowing only the corresponding terminals to associate with the BSs. The proposed technique is novel in that BSs are specially configured to use the same MAC address, and thus all the decisions on BS selection and handover are separated from those BSs and terminals and are put together into a centralized controller, while consistent layer-2 data paths in a backhaul network are also cooperatively configured. Simulation results show that the proposed technique can control the delay violation ratio of a target VoIP service and keep the ratio extremely low and comparable to that under IEEE 802.11e. A proof-of-concept prototype including two multi-channel virtualization-capable WiFi BSs and a BS switch is developed using off-the-shelf WiFi modules and a commercial OpenFlow switch. Experimental results show that the terminals can make a handover to a dedicated BS in less than 65 ms without any packet drop and association break, and confirm that the effect of the managed handover is limited even in a VoIP application.