Several EDCA parameter sets for improving channel access in IEEE 802.11ax networks

To improve efficiency of wide channel usage in dense scenarios, Wi-Fi community is currently developing a new amendment - 802.11ax - which introduces OFDMA in Wi-Fi. To provide backward compatibility, OFDMA works on top of CSMA/CA, native for Wi-Fi. Although OFDMA transmission is much more efficient than traditional one, the straightforward usage of 802.11ax functionality leads to the low ratio of OFDMA uplink transmissions. This problem can be solved by changing channel access parameters, which can be done with a legacy mechanism. However, in a heterogeneous network with legacy and 802.11ax stations, this mechanism leads to severe unfairness. In the paper, we describe our recent proposal, which solves the problem, and evaluate its performance with an analytical model.