Joint Effects of Node Density, Propagation, Wi-Fi Generation, and Transport Protocol on WLAN Performance: An ns-3 Study
Abstract: Wireless local area network (WLAN) performance is jointly shaped by medium contention, propagation, Wi-Fi configuration, and transport-layer behavior. This study evaluates IEEE 802.11g and IEEE 802.11ax in a single-access-point uplink topology, comparing UDP and TCP under Friis, LogDistance, and cascaded Friis-Nakagami propagation models. The factorial design spans 5 to 50 stations, six access-point distances from 5 m to 50 m, and three random seeds. Of 1,080 scheduled executions, 1,073 produced valid CSV outputs; seven runs terminated with internal ns-3 and cppyy segmentation errors and were excluded. Across the global scenario summaries, TCP FlowMonitor packet delivery ratios (PDRs) range from 0.994 to 0.997, whereas UDP PDRs range from 0.298 to 0.731. The highest mean aggregate throughput is 2.619 Mb/s for TCP under the configured IEEE 802.11ax mode with Friis propagation; UDP reaches 25.854 Mb/s in the same topology. These results show that packet delivery ratio, throughput, delay, and fairness must be considered together. FlowMonitor metrics are IP-flow observations, so the study does not establish application-level delivery or isolate optional IEEE 802.11ax multi-user mechanisms.