Research On Full-Duplex Link Scheduling Algorithm In Distributed WLAN

With the advancement and widespread application of network and wireless communication,"Internet of Everything" is becoming the mainstream of the world,people put forward higher requirements for network flexibility,resource utilization and service quality.On the one hand,the network needs to be used efficiently within the limited channel resources;on the other hand,the increase in business volume brought about by the increase in the number of users puts forward higher requirements on network performance.Traditional half-duplex communication cannot send and receive data in the same frequency band at the same time,and the utilization rate of wireless resources is greatly reduced.With breakthroughs in technologies such as self-interference cancellation,it has become possible to achieve simultaneous,co-time co-frequency full-duplex communications.However,to further realize full-duplex communication between nodes,the supports of the MAC protocols are also required in terms of node access and channel selection in the network.In this paper,the characteristics of existing full-duplex MAC protocols are analyzed and summarized.Aiming at the fairness of link scheduling in the process of full-duplex access,an optimization analysis of access control process based on CSMA/CA mechanism is proposed under the framework of distributed wireless local area network,and a full-duplex link scheduling algorithm W-FD based on node weight is proposed.The algorithm realizes link load balancing through node scheduling weight,which can improve the throughput of full-duplex link and reduce node access delay while paying attention to fairness.In order to further verify the applicability of the algorithm in mobile network,the node position prediction method is adopted to improve the calculation formula of node weight in dynamic link.Experimental results show:In static network,W-FD calculates the scheduling weight of neighbor nodes based on parameters such as the amount of data between nodes,mutual interference relationship and link scheduling interval,and selects the node with a higher scheduling weight in the neighborhood as the link initiator when the node accesses.At the same time,link establishment objects are generated according to the weight of neighbor nodes and a fullduplex link is established.The results show that: compared with traditional half-duplex link scheduling,W-FD reduces the link scheduling interval under the condition of ensuring node access fairness,and improves the throughput and delay performance of the network;Compared with full-duplex link scheduling,W-FD effectively improves the delay tail characteristics in a network with unbalanced traffic,and has better scheduling fairness while ensuring network throughput.In mobile networks,W-FD dynamically balances the scheduling weights of nodes based on changes in the relative positions of nodes,and adaptively adjusts the priority of access to the network to ensure the timely effectiveness of routing.The results show that W-FD can effectively inhibit the data packet loss when the node moves quickly.