Scheduling strategies and throughput optimization for the Downlink for IEEE 802.11ax and IEEE 802.11ac based networks

摘要

The new IEEE 802.11 standard, IEEE 802.11ax, has the challenging goal ofserving more users compared to its predecessor IEEE 802.11ac, enablingconsistent and reliable streams of data (average throughput) per station. Inthis paper we explore some of the IEEE 802.11ax new mechanisms and comparebetween the upper bounds on the throughputs of the Downlink unidirectional UDPMulti Users (MU) triadic based on Multiple-Input-Multiple-Output (MU-MIMO) andOrthogonal Frequency Division Multiple Access (OFDMA) transmission multiplexingformat in IEEE 802.11ax vs. IEEE 802.11ac in the Single User (SU) and MU modesfor 1, 4, 8, 16, 32 and 64 stations scenario in reliable and unreliablechannels. The comparison is made as a function of the Modulation and CodingSchemes (MCS) in use. In IEEE 802.11ax we consider two flavors ofacknowledgment operation settings where the maximum acknowledgment windows are64 or 256 respectively. In SU scenario IEEE 802.11ax upper bounds on thethroughputs outperform IEEE 802.11ac by about 52% and 74% in reliable andunreliable channels respectively. In MU-MIMO scenario IEEE 802.11ax upperbounds on the throughputs outperform IEEE 802.11ac by about 59% and 103% inreliable and unreliable channels respectively. Also, as the number of stationsincreases, the advantage of IEEE 802.11ax in terms of the access delay alsoincreases.