Research On Direct Communication Technology In The Next Generation WLAN

The development of industrial,business and multimedia applications has boosted the demand of user for more efficient and reliable wireless access networks,which drives the evolution of wireless local area network(WLAN)standards toward higher throughputs,lower latency and higher reliability.The next generation WLAN standard,IEEE 802.11 be,introduces multi-link communication technology for the first time by which multi-link devices can compete for multiple resources at the same time,increasing the transmission opportunities and significantly improving system throughputs.At present,there are few studies on the direct communication of WLAN multi-link devices,and with the directly applying of the existing direct communication method in multi-link devices will cause the problem of low link resource efficiency.Therefore,it is of great significance to study the research mechanism of WLAN multi-link direct communication.Aiming at the problems of direct communication between devices that cannot transmit and receive simultaneously,an Access Point(AP)-assisted WLAN multi-link direct communication scheme is designed,by which the AP schedules and manages the direct communication of the devices associated with it,competes for channel resources for the direct link communication transmissions between these devices,and allocates channel resources reasonably according to the actual transmission situation.For analyzing and evaluating the performance of the designed scheme,a two-dimensional discrete Markov chain model is used to mathematically model the multi-link direct connection communication scenario.Through the analysis and calculation of the transmission probability,combined with the channel access mechanism and the transmission parameters defined by the WLAN standard,the throughput performance gain of the designed scheme in the saturated state is analyzed and compared.Simulation results show that the proposed APassisted direct communication mechanism can improve the system throughput by about 15%,and its gain is more significant in large-scale networks.Further,based on the differences in the implementation of devices for the multi-link operations introduced in the next-generation WLAN standard,and in conjunction with the direct communication mechanism,the devices are classified into types according to their differential implementation of multi-link operation,and the potential problems in heterogeneous multi-link direct communication networks composed of devices with different performance are investigated,pointing out that the key to heterogeneous multi-link direct communication lies in satisfying the lower-performance devices.Finally,a scheme is designed to implement the enhanced multi-link single-radio operation in direct communication,which further enhances the efficiency of WLAN systems by flexible spatial multiplexing.The performance improvement brought by the enhanced multi-link singleradio operation based on the designed scheme is also evaluated,showing that the gains of this scheme will continue to increase as the amount of data transmitted in a single time increases,and with more than 40% improvement of the overall throughput of the system when using the longest PPDU allowed by the standard.