MC-VAP: A multi-connection virtual access point for high performance software-defined wireless networks

Aiming to exploit the power of multiple accesses from ubiquitous wireless networks, researchers employed multiple virtualized interfaces connecting to multiple APs for mobile users. However, these schemes require expensive modifications and additional cost on mobile device, which are hard to be implemented. Complementarily, in this paper, we propose a multi-connection virtual access point (MC-VAP) to virtualize and manipulate physical APs to provide multi-path transmission for a user while avoiding any modifications on the user side. As a result, the independent flows from an application can be dispatched to multiple paths separately and transmitted on multiple APs simultaneously, which can improve the throughput obviously. In order to maximize each application's throughput, the flow assignment is formulated as a mixed integer non-linear programming (MINLP) problem. In particular, a low-complexity heuristic algorithm, namely, narrowing search set with cutting-off solution space (NS-CoS) algorithm, is presented to solve the MINLP problem through relaxing it into simple LP problems. Moreover, we implement a prototype of MC-VAP, and the extensive real-world experiments demonstrate that MC-VAP can realize seamless handover and provide faster yet efficient solutions of flow assignment in contrast to the optimal method to achieve multifold throughput improvement for applications over regular WiFi.