Stability of rate control system with time-varying communication delays

Abstract

We adopt the optimization framework for the rate allocation problem proposed by Kelly and investigate the stability of the system with arbitrary communication delays between network elements with time-varying queue dynamics. We first present the conditions for the existence of a solution of the system. Second, we establish the conditions for the system stability with arbitrary delays for a family of popular utility and price functions, and then extend the results to more general utility and price functions. We demonstrate that the stability of such a system can be studied by considering a discrete time system derived from a simpler homogeneous delay case where all users have the same fixed delay. Numerical examples are provided to validate our analyses.