Research And Implementation Of IEEE802.11 Rate Adaptive Algorithm

With the rapid development of wireless communication technology and computer networks,wireless local area networks have been widely used in scenarios such as individual homes,corporate collectives,and various schools.The wireless LAN standard IEEE802.11 has undergone a series of developments and changes,forming a series of standards,such as IEEE802.11a/b/g/n/ac/ax,etc.This series of standards mainly regulates the physical(PHY)layer and media The working mechanism and characteristics of the access control(MAC)layer,and each standard physical layer provides multiple transmission rates,such as: IEEE802.11 b physical layer provides 4 transmission rates(1 ~ 11Mbps),IEEE802.11 a The physical layer provides 8 transmission rates(6~54Mbps),the physical layer of IEEE802.11 g provides 12 transmission rates(1~54Mbps),and the physical layer of IEEE802.11 n provides 60 transmission rates(6.5~600Mbps),And IEEE802.11ac/ax supports more transmission rates.Since using different transmission rates and different degrees of multi-site conflicts in the same channel environment can have a large impact on the throughput performance of the network,how to transmit according to the different channel environments and the number of stations in the network The choice of rate to maximize the throughput performance of the network has always been a difficult and hot issue in the industry.This paper compares and analyzes several existing rate adaptation algorithms,and proposes a rate adaptation algorithm based on the mechanism of "sacrificing locality to contribute to the whole".This algorithm is based on the signal-to-noise ratio interval(transmission rate area)in a single-site environment.)Correspondence with the transmission rate to select the transmission rate,in a multi-site environment according to the number of stations to adjust the signal-to-noise ratio value interval(transmission rate area)and the transmission rate corresponding to the transmission rate to adjust the transmission rate selection Program.The core idea of the algorithm in this paper is to sacrifice the success rate of sending packets in the low-rate area to reduce the time that the low-rate packet occupies the channel and alleviate the conflict of sending packets,and provide the saved channel resources to the sites in the high-rate area.To improve the average throughput of the entire system.The analysis found whether the average throughput of the entire system can be improved and thedegree of improvement is closely related to the corresponding area of various transmission rates and the number of stations in the environment.Under the conditions of the fixed simulation area in this paper,the optimal adjustment scheme of the transmission rate under the conditions of the number of stations can be obtained through simulation experiments.Finally,the network simulation tool NS3 is used to compare the simulation results with the existing algorithms including CARA,Minstrel,RRAA,AMRR,ARF,and AARF algorithms.It is found that the algorithm in this paper compares with the average system throughput in a single-site or multi-site environment.CARA,Minstrel,AMRR,ARF,and AARF algorithms all exhibit better performance.When the number of sites reaches a certain value,the performance of the algorithm in this paper begins to be weaker than the RRAA algorithm.