LSR: Link-aware Spatial Reuse in IEEE 802.11ax WLANs

The upsurge of mobile traffic volume has led to dense deployment of IEEE 802.11 wireless local area networks (WLANs). To enhance spectral efficiency in dense WLAN deployments, a new 802.11 amendment, namely 802.11ax, introduces overlapping basic service set packet detection-based spatial reuse (OBSS PD-based SR) operation. Although the OBSS PD-based SR operation enables more simultaneous transmissions among OBSSs, whether it improves network performance is highly uncertain and depends on the mutual interference among the simultaneous transmission links. In this paper, we propose a link-aware SR scheme, named LSR, that facilitates simultaneous transmissions among OBSSs considering the mutual interference. LSR efficiently exploits SR transmission opportunities by selecting the appropriate link for the SR transmission while sufficiently protecting the ongoing transmission. Moreover, the proposed method allows BSSs to coordinate with each other in a distributed manner without incurring additional control message exchange. Through extensive ns-3 simulation, we demonstrate that LSR significantly improves the network performance compared with legacy 802.11 and the OBSS PD-based SR operation.