An Adaptive TXOP Sharing Algorithm for Multimedia Traffic in IEEE802.11ac Networks

IEEE802.11 standard is continuously evolving to satisfy the increasing throughput and QoS (Quality of Service) requirements of diverse user applications. One of the advanced key features of the IEEE802.11 standard is the introduction of the DL-MU-MIMO (Downlink Multi-user Multiple Input and Multiple Output) techniques which enables a multi-antenna access point to serve multiple download users concurrently. The MAC layer of the 802.11ac protocol utilises the TXOP sharing technique to support the DL-MU-MIMO operating mode. In this paper, we propose a new TXOP sharing algorithm for the 802.11ac MAC protocol to offer high throughput and QoS for multimedia traffic. The proposed algorithm is referred to as FRA−TXOPE (Flow Rate Adaptive Transmission Opportunity Extension), enhancing our previously published FRA−TXOP algorithm. The FRA−TXOP E algorithm adaptively shares the TXOP resources with primary and secondary traffic sources by continuously monitoring different traffic source flow rates and QoS requirements. Simulation results show that the proposed algorithms significantly enhance the QoS performance of all traffic sources by improving the network throughput and channel utilisation in IEEE802.11ac WLANs.