Understanding Multi-link Operation in Wi-Fi 7: Performance, Anomalies, and Solutions

Marc Carrascosa-Zamacois, Giovanni Geraci, Lorenzo Galati-Giordano, Anders Jonsson, Boris Bellalta

Abstract: Will Wi-Fi 7, conceived to support extremely high throughput, also deliver consistently low delay? The best hope seems to lie in allowing next-generation devices to access multiple channels via multi-link operation (MLO). In this paper, we aim to advance the understanding of MLO, placing the spotlight on its packet delay performance. We show that MLO devices can take advantage of multiple contention-free links to significantly reduce their transmission time, but also that they can occasionally starve one another and surprisingly incur a higher delay than that of a well planned legacy single link operation. We examine and explain this anomaly, also putting forth practical workarounds.