Performance Evaluation of Multi-Link Single-Radio and Multi-Radio Devices in Heterogeneous Wi-Fi 7 Networks

The IEEE 802.11be (Wi-Fi 7) standard for WLANs, which is currently under development, will allow for a multiple throughput increase and lower latency in comparison with the previous IEEE 802.11ax (Wi-Fi 6) standard. One of the main novelties of IEEE 802.11be to achieve this is the native support for the multi-link feature, and this can be done using single or multiple radio interfaces. When using one radio interface, the device can quickly switch it from a busy channel to a free one and consequently reduce the channel access delay. However, transmission can only be performed in one channel. The usage of multiple radio interfaces allows for simultaneous data transmission on multiple channels, but the radio interfaces can interfere with each other, so the standard describes an operation mode for the mitigation of such interference. In this multiple channels operation mode, one performs either joint synchronized transmission or joint synchronized signal reception. The article describes algorithms for switching a single radio interface of a multi-link device, which allow to increase its throughput. It also compares the performance of multi-link devices with one and several radio interfaces.