Modeling the TXOP Sharing Mechanism of IEEE 802.11ac Enhanced Distributed Channel Access in Non-Saturated Conditions

IEEE 802.11ac standard, adopting a downlink multi-user multiple-input and multiple-output (DL-MU-MIMO) scheme, can significantly improve the performance of wireless local area networks (WLANs). To support the DL-MU-MIMO technology, a transmission opportunity (TXOP) sharing mechanism has been proposed to allow an access point (AP) to communicate with multiple users simultaneously. In this letter, we present an analytical model based on Markov chains for a non-saturated IEEE 802.11ac enhanced distributed channel access (EDCA) network, which supports the TXOP sharing mechanism. The analytical model computes the 802.11ac EDCA throughput, in the assumption of ideal channel conditions. Extensive simulation and analysis results show that the analytical model can accurately predict the throughput of the 802.11ac networks under non-saturated operation.