IEEE 802.11be Multi-Link Operation: When the Best Could Be to Use Only a Single Interface

TL;DR

This paper evaluates traffic distribution strategies in IEEE 802.11be's multi-link operation, finding that assigning new flows to the least congested interface often yields optimal performance despite the potential benefits of multi-link use.

Contribution

The study compares various traffic allocation policies in MLO, highlighting that simple, congestion-aware single-interface assignment can outperform complex multi-link strategies.

Findings

Congestion-aware policies outperform static ones.

Distributing traffic across multiple links increases vulnerability to neighboring network activity.

Assigning new flows to the least congested interface yields the best performance.

Abstract

The multi-link operation (MLO) is a new feature proposed to be part of the IEEE 802.11be Extremely High Throughput (EHT) amendment. Through MLO, access points and stations will be provided with the capabilities to transmit and receive data from the same traffic flow over multiple radio interfaces. However, the question on how traffic flows should be distributed over the different interfaces to maximize the WLAN performance is still unresolved. To that end, we evaluate in this article different traffic allocation policies, under a wide variety of scenarios and traffic loads, in order to shed some light on that question. The obtained results confirm that congestion-aware policies outperform static ones. However, and more importantly, the results also reveal that traffic flows become highly vulnerable to the activity of neighboring networks when they are distributed across multiple links. As a result, the best performance is obtained when a new arriving flow is simply assigned entirely to the emptiest interface.