Research On Multi-AP Coordination Technology In The Next Generation WLAN

With the emergence of emerging applications such as AR,VR and cloud games,people have higher and higher requirements for network throughput and access delay,which makes the update of WLAN standards more rapid.In the next generation WLAN standard IEEE802.11 be,multi-AP cooperation technology is proposed,which can solve the problem of mutual interference between APs in the scenario of intensive deployment of APs,maximize the use of limited time-frequency domain and air interface resources,reduce competition,improve system performance and transmission efficiency.This paper aims to study the multiAP cooperation mechanism in 802.11 be.The specific research results and contributions are summarized as follows:Firstly,a new unified uplink and downlink multi-AP coordination trigger mechanism is proposed,and a unified trigger frame is designed.The AP that obtains the transmission opportunity by competition can share the transmission opportunity with other APs in the same coordination set through the designed trigger frame,so as to carry out multi-AP coordination transmission,and the designed trigger frame supports different types of multiAP coordination transmission modes.Compared with the existing coordination methods,the proposed multi-AP coordination method can effectively reduce the signaling overhead and improve the resource utilization.Finally,the simulation verifies the effectiveness of the proposed multi-AP coordination method in multi-AP scenarios.Secondly,the optimization of resource scheduling and selection before transmission opportunity sharing in AP coordination set in the scenario of multi-AP coordination sets coexisting in large-scale WLAN networks is considered.In the existing multi-AP coordination mechanism,the shared objects selected by APs may conflict with the ongoing transmitting APs or about to be transmitted in other coordination sets,based on this,considering the possible conflicts in the network,the traffic priority and fairness of each AP,the optimization of resource scheduling and selection before transmission opportunity sharing in AP coordination set is modeled and transformed into a mixed integer linear programming problem with the goal of minimizing the dissatisfaction of AP in the network.Due to the high complexity of solving the global optimal solution,based on the idea of greedy algorithm,a sub-optimal low complexity algorithm is proposed.Finally,the effectiveness of the algorithm is verified by simulation.The results show that the performance of the proposed sub-optimal algorithm is close to the optimal theory.