Quasiperiodic motion induced by heterogeneous delays in a simplified internet congestion control model

In this paper, a simplified congestion control model is considered to study the quasiperiodic motion induced by heterogenous time delays. Analysis for the stability of the equilibrium shows that the Hopf bifurcation curves with diverse frequencies may intersect at the so-called non-resonant double Hopf bifurcation point. Choosing the delays as the bifurcation parameters and employing the method of multiple scales, the amplitude-frequency equations or normal form equations are obtained theoretically. Based on these equations, the dynamics near the bifurcation point is classified. The values of the delays for which the quasiperiodic motion exists can be predicted with an acceptable accuracy. This result provides a reference in designing and optimizing the network systems. (C) 2012 Elsevier Ltd. All rights reserved.