Our paper has been accepted to INFOCOM 2025

Posted Date: Dec 6, 2024

Kanghyun Lee's work titled "Enriching Multi-User OFDMA in Wi-Fi Networks with Frequency-Selective Channel Awareness" has been accepted for inclusion in the IEEE INFOCOM 2025 conference technical program.

Congratulations!

Enriching Multi-User OFDMA in Wi-Fi Networks with Frequency-Selective Channel Awareness

Kanghyun Lee, Youngwook Son, Jongyeon Park, and Saewoong Bahk

Abstract

Recent studies on multi-user (MU) orthogonal frequency division multiple access (OFDMA) in IEEE 802.11ax highlight its advantages in terms of network efficiency under low traffic loads by mitigating channel access overheads. They also claim that MU-OFDMA becomes only susceptible to extra overheads under saturated traffic conditions, even leading to throughput loss compared to legacy single-user (SU) transmissions. Against this perspective, we notice that MU-OFDMA potentially enhances overall capacity of Wi-Fi networks by harnessing small resource units (RUs) flexibly over frequency-selective channels. Through measurements, we find that current RU allocation in commercial APs cannot achieve optimal performance due to the lack of consideration for detailed channel characteristics. We conceptualize a resource allocation strategy that accounts for distinct link quality across RUs, with its effectiveness verified through proof-of-concept study as well as extensive performance analysis. Based on these findings, we present ChORUS, a standard-compliant framework to realize optimal RU allocation by fully exploiting frequency-selective channels and their diversity among users. Our trace-driven simulation using standard channel models and real-world traces demonstrates that ChORUS significantly enhances throughput performance over SU, ensuring network capacity elevation through MU-OFDMA.