A resource allocation algorithm for the OFDMA mechanism to improve efficiency, fairness and preserve packet ordering in WLANs

Abstract

The use of Orthogonal Frequency Division Multiple Access (OFDMA) was first introduced to Wireless Local Area Networks (WLANs) in the IEEE 802.11ax standard. Under the OFDMA mechanism, users can access different channel bandwidths to transmit their packets. As the bandwidth demands of users using the Internet increase, how to allocate channel resources for the OFDMA mechanism to improve the channel utilisation and fairness of the network has been a challenge. This paper proposes a modified Dynamic Programming algorithm combined with the Timsort (MDPT) to solve the resource allocation problem for downlink traffic under the OFDMA mechanism. The experiments compare the channel utilisation, Jain’s Fairness index (JFI), R-value and computation time of MDPT with other optimisation techniques. According to the simulation results, MDPT can generate an RU allocation scheme that improves the efficiency and fairness of the network, preserves packet ordering and can generate an optimal RU allocation scheme within an RU allocation interval.