ADWISERv2: A Plug-and-play Controller for Managing TCP Transfers in IEEE~802.11 Infrastructure WLANs with Multiple Access Points

TL;DR

This paper introduces ADWISERv2, a plug-and-play controller that manages TCP transfers in multi-AP IEEE 802.11 WLANs, improving fairness and efficiency without hardware modifications.

Contribution

It proposes a novel overlay controller with a utility optimization-based scheduler for multi-AP WLANs, handling TCP performance issues without hardware changes.

Findings

Improved TCP fairness and throughput in multi-AP WLANs

Effective adaptation algorithm for fair queuing scheduler

Validated results on real testbed demonstrating efficacy

Abstract

In this paper, we present a generic plug-and-play controller that ensures fair and efficient operation of IEEE~802.11 infrastructure wireless local area networks with multiple co-channel access points, without any change to hardware/firmware of the network devices. Our controller addresses performance issues of TCP transfers in multi-AP WLANs, by overlaying a coarse time-slicing scheduler on top of a cascaded fair queuing scheduler. The time slices and queue weights, used in our controller, are obtained from the solution of a constrained utility optimization formulation. A study of the impact of coarse time-slicing on TCP is also presented in this paper. We present an improved algorithm for adaptation of the service rate of the fair queuing scheduler and provide experimental results to illustrate its efficacy. We also present the changes that need to be incorporated to the proposed approach, to handle short-lived and interactive TCP flows. Finally, we report the results of experiments performed on a real testbed, demonstrating the efficacy of our controller.