Optimizing TCP Goodput and Delay in next generation IEEE 802.11 (ax) devices

TL;DR

This paper evaluates three scheduling strategies for IEEE 802.11ax to optimize TCP goodput and delay, comparing single-user and multi-user modes across different station counts and analyzing the impact of delayed acknowledgments.

Contribution

It introduces and compares three scheduling strategies for TCP data transmission in IEEE 802.11ax, highlighting their performance differences based on station count and features.

Findings

MU strategy outperforms SU for up to 8 stations

SU strategies outperform MU for 64 stations

Delayed Acks significantly affect goodput with short TCP segments

Abstract

In this paper we suggest three scheduling strategies for the IEEE 802.11ax transmis- sion of DL unidirectional TCP data from the Access Point to stations. Two strategies are based on the Single User operation mode and one is based on the Multi User operation mode, using Multi User Multiple-Input-Multiple-Output (MU-MIMO) and OFDMA. We measure the Goodput of the system as a function of the time intervals over which these Goodputs are received in all three strategies. For up to 8 stations the MU strategy outperforms the SU. For 16 and 32 stations it is not clear whether MU outperforms SU or vice versa. For 64 stations the SU strategies outperform the MU significantly. We also checked the influence of the Delayed Acks feature on the received Goodputs and found that this feature has significance only when the TCP data segments are relatively short.