On Designing Lyapunov-Krasovskii Based AQM for Routers Supporting TCP Flows

TL;DR

This paper develops a Lyapunov-Krasovskii based Active Queue Management (AQM) for routers supporting TCP flows, using control theory and convex optimization to ensure stability, with simulation validation.

Contribution

It introduces a novel Lyapunov-Krasovskii functional approach for designing robust AQM schemes based on linear matrix inequalities.

Findings

The proposed AQM stabilizes TCP flow models.

The synthesis reduces to solving convex LMIs.

Simulations confirm effectiveness of the approach.

Abstract

For the last few years, we assist to a growing interest of designing AQM (Active Queue Management) using control theory. In this paper, we focus on the synthesis of an AQM based on the Lyapunov theory for time delay systems. With the help of a recently developed Lyapunov-Krasovskii functional and using a state space representation of a linearized fluid model of TCP, two robust AQMs stabilizing the TCP model are constructed. Notice that our results are constructive and the synthesis problem is reduced to a convex optimization scheme expressed in terms of linear matrix inequalities (LMIs). Finally, an example extracted from the literature and simulations via {\it NS simulator} support our study.