A2P: A Scalable OFDMA Polling Algorithm for Time-Sensitive Wi-Fi Networks

TL;DR

The paper addresses the polling bottleneck in uplink OFDMA for dense, time-sensitive Wi‑Fi networks. It introduces A2P, a hybrid polling algorithm that maintains a dynamic polling list of active STAs and coordinates UL OFDMA transmissions while temporarily disabling EDCA for those STAs to reduce contention and polling overhead. The approach is standards-compliant and leverages round-robin polling with ARI-controlled channel access to balance UL and DL, achieving lower end-to-end delay and higher capacity than EDCA, pure OFDMA, or OFDMA+EDCA baselines in a teleconferencing scenario. Across NS-3 simulations, A2P enables scalable, low-latency operation, notably supporting up to about 20 STAs without packet loss at 40 MHz bandwidth, highlighting its practical impact for high-density, time-sensitive Wi‑Fi deployments.

Abstract

Over the years, advancements such as increased bandwidth, new modulation and coding schemes, frame aggregation, and the use of multiple antennas have been employed to enhance Wi-Fi performance. Nonetheless, as network density and the demand for low-latency applications increases, contention delays and retransmissions have become obstacles to efficient Wi-Fi deployment in modern scenarios. The introduction of Orthogonal Frequency-Division Multiple Access (OFDMA) in the IEEE 802.11 standard allows simultaneous transmissions to and from multiple users within the same transmission opportunity, thereby reducing the contention. However, the AP must efficiently manage the resource allocation, particularly in uplink scenarios where it lacks prior knowledge of users' buffer statuses, thus making polling a critical bottleneck in networks with a high number of users with sporadic traffic pattern. This paper addresses the polling problem and introduces the A2P algorithm, designed to enable scalable and efficient polling in high-density OFDMA-based time sensitive Wi-Fi networks. Simulation results show that A2P outperforms the alternative schemes by maintaining significantly lower delay and packet loss in dense time-sensitive teleconferencing scenario.

Figures (7)

• Figure 1: UL OFDMA frame exchange sequence
• Figure 2: Model of system's traffic pattern
• Figure 3: Flow chart of the algorithmic procedure at STA side
• Figure 4: Flow chart of the algorithmic procedure at AP side
• Figure 5: Performance evaluation: average delay