Stability analysis of a novel exponential-RED model with heterogeneous delays

Active Queue Management (AQM) schema provides an early indication of incipient congestion to the sources. However, in developing the AQM schema, there are some urgent problems to be solved, which are how to achieve higher bandwidth utility and smaller queuing delay, keep the stability of congestion control model, and derive some sufficient conditions for the stability. In this paper, we firstly demonstrate that the stability of most of the AQM algorithm is achieved by modifying the packet drop/mark probability function, and then analyze the merit and drawback of RED and its variants. We develop a discrete-time dynamical feedback system model with delay for a TCP/Reno network. By analyzing the dynamical model proposed based on frequency domain, the sufficient conditions are derived. The local stability conditions are validated by some simulation results in ns2. The simulation results show the proposed schema here can achieve the stable average queue length with high link utilization.