A Prediction Algorithm for Feedback Control Models with Long Delays

It is well known that feedback control may be diicult in a network with long propagation delays (with large bandwidth-delay products). Various feedback-based congestion control algorithms considered for networks with long delays have been reviewed from control theoretical viewpoints. Most existing control algorithms are shown to provide threshold-based control technique. However, as the propagation delay becomes signiicant, the past history over the entire time lag may have to be incorporated into the control strategy. An adaptive algorithm based on the optimal least mean square error technique is presented. The algorithm attempts to predict a future buuer size from weight (slope) adaptation of unknown functions which are used for feedback control. Simulation results are presented, which show the eeectiveness of the algorithm.