Design And Implementation Of Soft MAC For 802.11ax Prototype Access Point

802.11 ax standard,which is designed for the rapid development of wireless devices and the rapid increase of the amount of WLAN users and can effectively improve the network quality in multi-user scenarios,is IEEE's next generation WLAN standard.Since 802.11 ax is still in the research phase,it is of great significance to develop an 802.11 ax prototype for the formulation and marketing of the 802.11 ax standard.The access point(AP)is the core device of a WLAN system,providing access services and data access for other stations.In the 802.11 ax prototype system,the functions at the MAC layer of AP are divided into two parts.These two parts are defined as the soft MAC and the hard MAC,and the soft MAC of AP is the core of managing the users and scheduling the resources.There is no mature 802.11 ax prototype on the market,thus,the implemention of the soft MAC for 802.11 ax AP is carried out on the basis of exsiting 802.11n/ac standards related products.On the basis of 802.11n/ac standards,the technologies of OFDMA and dynamic frame fragmentation are introduced in 802.11 ax standard to improve the system performance.The technology of OFDMA,which allows subcarriers on a subchannel to be used by multiple users simultaneously,can greatly improve the throughput.Multi-user dynamic scheduling mechanism based on OFDMA is the key to the system.Round Robin,Max C/I and Proportional Fairness are the classical scheduling algorithms,among which the Max C/I algorithm can maximize the throughput.On the basis of the Max C/I algorithm,a dynamic scheduling mechanism based on hardware feedback,which can reduce the delay,is proposed combined with the actual environment to optimize the system.Dynamic frame fragmentation,which slices the packets according to the resources allocation,can effectively improve the resource utilization,but system overhead is also brought out.The condition of whether dynamic frame fragmentation is adopted is determined by carefully analysis according to the resources allocation and the system overhead.And to implement the MAC layer without relying on the physical layer to improve the development efficiency,the mechanism of transmitting wireless packets through wireline networks is proposed to achieve normal communication between network devices when the wireless physical layer is masked.Finally,the soft MAC for 802.11 ax AP is carried out.And a test for the system is conducted,which verifies that the soft MAC of the AP in this paper is successfully accomplished and the required 5Gbps throughput in both uplink and downlink is achieved.