EWMAX and NDIST: RSSI filtering mechanisms for handoff algorithms in dense networks

Abstract

Handoffs are common in wireless networks with high device density. Since the IEEE 802.11 standard does not specify the criteria for initiating these handoffs, their implementation varies by manufacturer. Most current solutions rely on the Received Signal Strength Indicator (RSSI) as a key performance metric, which often leads to unstable associations—a phenomenon often referred to as the “ping-pong” effect. To address this effect, we propose EWMAX and NDIST, two RSSI filtering mechanisms designed to enhance association stability with minimal delay in handoff triggering. Comparative tests demonstrate that both EWMAX and NDIST improve stability without significantly increasing delay. However, a comprehensive evaluation reveals that EWMAX dominates the majority of results on the Pareto frontier, often generating the best solutions. Specifically, EWMAX matched NDIST in stability and outperformed it with a 24.64% reduction in delay, demonstrating superior performance in the evaluated scenario.