Elastic TDMA Overlay for Dense Wi-Fi Networks

Abstract

Dense Wi-Fi networks can lose efficiency when many uplink stations contend at the same time. This paper presents an access-policy study of an AP-managed elastic TDMA-style scheduled-access overlay for dense WLANs. The intended policy reserves protected airtime for active hybrid-capable stations while leaving fallback CSMA/CA available for regular stations and new reservation requests. We evaluate the policy with a policy-level ns-3 model layered over stock Wi-Fi behavior. The model uses scheduled queue release and NAV-like regular-station deferral to isolate access-policy behavior before full MAC integration. In a matched 16-station high-load campaign, a mixed 8 hybrid / 8 regular configuration with NAV-like deferral improves throughput by 6.51%, delivery by 5.74 percentage points, Wi-Fi TX failures by $\mathbf{6 0 . 3 4 \%}$, and retransmissions by $\mathbf{2 8 . 1 8 \%}$ relative to all-regular standard Wi-Fi. Paired five-run differences give preliminary statistical support for the protected mixed case, including throughput gains of $1.175 \pm 0.372$ Mbps and delivery gains of $5.743 \pm 1.820$ percentage points. A NAV-like-off stress case degrades, representing missed or unenforced protection. A fixed 8H/8R timing sweep shows that protected airtime must be sized carefully: 5 ms is best among the tested block durations, while oversized protected blocks starve fallback contention. These results support AP-managed elastic TDMA-style access policy and motivate future MAC-integrated validation.