Improving RED Performance during Handovers in Wireless IP Networks

Abstract

The random early detection (RED) is a widely used active queue management (AQM) algorithm for congestion avoidance. It monitors the average queue length to detect incipient congestion and notifies the connections of congestion to adjust their sending rate. During a handover, all the active connections of the mobile node will be diverted to the new network and increase the total traffic there immediately. Because RED uses an exponential weighted moving average (EWMA) to calculate the queue length, it will be too slow to track this rapid change and fail to react correctly. In this paper we propose a dual RED algorithm to accommodate the coming handed-over connections quickly while keeping the link utilization high. The improvement is verified with simulations.