ENHANCING AQM TO COMBAT WIRELESS LOSSES

Abstract

In order to maintain a small, stable backlog at an internet router buffer, active queue management (AQM) algorithms drop packets probabilistically at the onset of congestion. This causes Transmission Control Protocol (TCP) data flow rates to reduce. However, wireless losses may be misinterpreted as congestive losses and induce spurious reductions in flow rates. A prior art AQM with random early detection (RED), fails to maintain a stable backlog under time-varying wireless losses. However, the present invention can resolve the problem and provide a robust tracking of the backlog to a preset reference level by applying a control-theoretic vehicle, Internal Model principle, to realize such tracking. An integral controller (IC) is used as an embodiment of the principle that is robust against time-varying wireless losses under various network scenarios.