Research On Uplink Multiple Access Technology Based On Service QoS Priority In IEEE 802.11ax

With the rapid development of mobile Internet,WLAN is widely used in people's daily life due to its advantages such as high throughput,low cost and simple network deployment.However,with the continuous increase in the number of wireless communication devices,more and more users need to share an AP,which causes the user's access efficiency to be greatly reduced,which seriously affects the user's experience.Nowadays,the single channel access mechanism in the traditional IEEE 802.11 standard can no longer meet the needs of users in dense surroundings,so the latest IEEE 802.11 ax standard has become the focus of people's research and discussion.Due to the introduction of OFDMA technology at the physical layer,the IEEE 802.11 ax standard divides the entire channel into multiple subchannels,so that multiple users can transmit data on different subchannels at the same time,which not only increases the probability of users accessing the channel,but also greatly improves system throughput.However,many current multi-access protocols based on IEEE 802.11 ax only consider the increase of throughput and do not consider the Qo S requirements of different priority services.Therefore,it is of great significance to develop a Qo S-oriented IEEE 802.11 ax multiple access protocol.This paper proposes an uplink multiple access protocol based on service Qo S priorities to address the Qo S requirements of different priority services.In the channel contention phase,the synchronization of multiple subchannels under the OFDMA mechanism is ensured by the full channel listening method.At the same time,a Type field is added to the RTS frame sent by the STA to distinguish different priority business users.In the data transmission phase,a probability of rejection is proposed for low-priority service users,and the probability of low-priority service user being rejected is associated with the number of retransmissions of the user's MAC layer.If the number of times that the user is retransmitted is greater,it means that the channel competition is more fierce at this time,then the probability of low-priority service users being rejected should be increased to ensure the Qo S of high-priority service users.This article adds a new R-ACK frame to indicate whether low-priority service users are rejected.If the AP sends an R-ACK frame to the STA,it indicates that the data sent by the user is rejected.Subsequently,this paper analyzes the performance of the proposed multiple access protocol through an improved two-dimensional Markov model,and deduces the calculation formulas for throughput and average delay under saturated conditions.By analyzing the simulation results,it is proved that the proposed multiple access protocol can make high-priority service users occupy more channel resources,and ensure the throughput of high-priority service users while reducing the average delay of high-priority service users and the probability of its packets being dropped.