Validation of the ns-3 802.11ax OFDMA implementation

The introduction of Orthogonal Frequency Division Multiple Access (OFDMA) in 802.11ax signifies a change in role for the Access Point (AP) in WiFi networks, with the opportunity to implement more complex scheduling logic to handle Downlink (DL) traffic flows and simultaneously act as coordinator of Multi User (MU) Uplink (UL) transmissions. In this context it becomes necessary to develop reliable network analysis and simulation tools that allow for an in-depth analysis of the trade-offs involved in the usage of OFDMA, especially considering that the standard leaves much of the actual scheduling algorithmic details to vendor-specific implementation. In this work we validate the recent OFDMA implementation in ns-3's wifi module, within the context of a re-design effort to improve modularity and support for future WiFi amendments. ns-3 based OFDMA performance evaluation via simulation is shown to match the predictions of an analytical approach in some simplified scenarios.