Robust Stability Analysis of a Class of Smith Predictor-based Congestion Control Algorithms for Computer Networks

Luca de Cicco (1) , Saverio Mascolo (1) , Silviu-Iulian Niculescu (2)

1 Polytechnic University of Bari / Politecnico di Bari
2 L2S - Laboratoire des signaux et systèmes

Congestion control is a fundamental building block in packet switching networks such as the Internet due to the sharing of communication resources. It has been shown that the plant dynamics is essentially made of an integrator plus time delay and that a proportional controller plus a Smith predictor is a simple and eective controller. It has been also shown that the today running TCP congestion control can be modelled using a Smith predictor plus a proportional controller. Due to the importance of this control structure in the eld of data network congestion control, we analyze the robust stability of the closed loop system in the face of delay uncertainties that in data networks are present due to queuing. In particular, by applying a geometric approach, we derive a bound on the proportional controller gain which is necessary and sucient to guarantee stability given a bound on the delay uncertainty.

Mots clés: Networked control systems (NCSs); switched systems; optimal control; Time-delay systems; Robust stability; congestion control; Smith predictor

Domaines: Sciences de l'ingénieur [physics]; Automatique / Robotique

Luca de Cicco, Saverio Mascolo, Silviu-Iulian Niculescu. Robust Stability Analysis of a Class of Smith Predictor-based Congestion Control Algorithms for Computer Networks. 8th IFAC Workshop on Time-Delay Systems, Sep 2009, Sinaia, Romania. pp.201-206, ⟨10.3182/20090901-3-RO-4009.00032⟩. ⟨hal-02291626⟩