Performance and simulation analysis of 802.11ax OFDMA in contention-driven scenarios

Abstract

The 802.11ax standard introduces Orthogonal Frequency Division Multiple Access (OFDMA), shifting the role of access points (APs) in Wi-Fi networks. This shift integrates intricate scheduling logic, assigning coordinator roles to APs for multi-user uplink (MU-UL) transmissions and streamlining downlink traffic flows. These developments require robust network analysis and simulation tools to investigate the trade-offs associated with using OFDMA. In this study, we validate the implementation of OFDMA in ns-3 Wi-Fi module, enhancing flexibility and support for future updates through a redesign process. Previous studies validate the OFDMA implementation in the ns-3 Wi-Fi module by matching the simulation to predictions of analytical models. In this work, we demonstrate that OFDMA performance aligns with analytical predictions through simulation-based performance evaluations using ns-3 in some contention-driven use cases. The proposed system operates in both the uplink (UL) and downlink (DL) directions, implementing two scheduling logics to manage DL traffic flows and coordinate MU-UL transmissions. Simulation time is reduced by introducing parallel computing in the system. This study provides a reliable network analysis and simulation framework that thoroughly examines the trade-offs involved in using OFDMA.