TCP Latency-Sensitive Applications Over MLO in Wi-Fi 7

Wi-Fi 7 introduces Multi-Link Operation (MLO) as a prominent feature for improving network performance. MLO enables an increase in the number of parallel transmissions, thus increasing the network throughput and reducing the network latency. How to schedule concurrent transmissions over multiple links is an open research challenge. Furthermore, cross-layer interaction between MLO and transmission control protocols such as TCP is not yet properly investigated. In this work, we investigate the interaction between MLO in STR mode and TCP traffic. We conducted the analysis through realistic ns-3 simulations. Results show that TCP performance improves with MLO (with respect to the single-link case) when an additional link is empty while degrades when an additional link is even partially loaded. We also tested various TID-to-link mapping strategies to alleviate the performance degradation, highlighting the need for further investigations.