IEEE 802.11ax Spatial Reuse Improvement: An Interference-Based Channel Access Algorithm

Wi-Fi is the dominant way of connecting indoor mobile devices to the Internet. The main reason behind the huge adoption of this technology is the simplicity of IEEE 802.11 protocols which in turn offer low-cost ownership and maintenance combined with the ability to offer high data rates to end users. The increasing demand in traffic volumes leads to the continuous deployment of access points (APs) resulting in densification of the IEEE 802.11 networks. This fact, instead of enhancing the efficiency of wireless local area networks (WLANs) degrades their overall performance due to cochannel interference between overlapped basic services sets (OBSSs). One of the main goals of the under-development IEEE 802.11ax amendment is to address the WLAN densification problem by improving spatial reuse (SR). In this article we present and evaluate a channel access algorithm, which considers the expected interference that nodes will suffer by a concurrent transmission so to decide if transmission or defer will take place. It is shown that the proposed interference based dynamic channel algorithm (IB-DCA) offers significant SR performance gains comparing to the existing channel access algorithms, in terms of the station mean data rate, for all the stations in a IEEE 802.11ax dense deployment.