Control Theoretic Optimization of 802.11 WLANs: Implementation and Experimental Evaluation

TL;DR

This paper implements and evaluates control-theoretic adaptive algorithms for 802.11 WLANs, demonstrating significant throughput improvements and analyzing the advantages of centralized over distributed schemes in realistic large-scale testbeds.

Contribution

It introduces and experimentally validates two adaptive algorithms based on control theory for WLANs, highlighting the effectiveness of centralized control in practical deployments.

Findings

Both algorithms outperform standard configurations in throughput.

Centralized control significantly improves performance over distributed schemes.

Distributed schemes have inherent limitations in large-scale scenarios.

Abstract

In 802.11 WLANs, adapting the contention parameters to network conditions results in substantial performance improvements. Even though the ability to change these parameters has been available in standard devices for years, so far no adaptive mechanism using this functionality has been validated in a realistic deployment. In this paper we report our experiences with implementing and evaluating two adaptive algorithms based on control theory, one centralized and one distributed, in a large-scale testbed consisting of 18 commercial off-the-shelf devices. We conduct extensive measurements, considering different network conditions in terms of number of active nodes, link qualities and traffic generated. We show that both algorithms significantly outperform the standard configuration in terms of total throughput. We also identify the limitations inherent in distributed schemes, and demonstrate that the centralized approach substantially improves performance under a large variety of scenarios, which confirms its suitability for real deployments.