Rate Adaptation: A Practical Algorithm for Heterogeneous Wi-Fi Networks

This paper addresses a practical rate adaptation algorithm for heterogeneous Wi-Fi networks. This low complexity algorithm is efficient and applicable for both Legacy and recent Wi-Fi devices which are based on IEEE 802.11n/ac/ax/be standards. The algorithm maintains for each station a statistic of the Packet-Error-Rate of its feasible transmission rates considering its actual received signal strength indicator available at the access point. For each station, the algorithm then deduces the achievable throughput of these feasible transmission rates and selects the best one which results in the highest achievable throughput. We simulated this algorithm in MATLAB as well as implemented it in a Wi-Fi access point which is based on Qualcomm chip-set. We measured the performance of this device in laboratory and real Over-The-Air environments. The simulation and measurement results confirmed that the rate quickly converges to the optimal value when the channel condition suddenly changes. In addition, this algorithm helps in improving the achievable throughput of the applied device by 15% without any hardware upgrade.