Scheduling Strategies and Throughput Optimization for the Uplink for IEEE 802.11ax and IEEE 802.11ac Based Networks

Abstract

The new IEEE 802.11 standard, IEEE 802.11ax, has the challenging goal of serving more Uplink (UL) traffic and users as compared with his predecessor IEEE 802.11ac, enabling consistent and reliable streams of data (average throughput) per station. In this paper we explore several new IEEE 802.11ax UL scheduling mechanisms and compare between the maximum throughputs of unidirectional UDP Multi Users (MU) triadic. The evaluation is conducted based on Multiple-Input-Multiple-Output (MIMO) and Orthogonal Frequency Division Multiple Access (OFDMA) transmission multiplexing format in IEEE 802.11ax vs. the CSMA/CA MAC in IEEE 802.11ac in the Single User (SU) and MU modes for 1, 4, 8, 16, 32 and 64 stations scenario in reliable and unreliable channels. The comparison is conducted as a function of the Modulation and Coding Schemes (MCS) in use. In IEEE 802.11ax we consider two new flavors of acknowledgment operation settings, where the maximum acknowledgment windows are 64 or 256 respectively. In SU scenario the throughputs of IEEE 802.11ax are larger than those of IEEE 802.11ac by 64% and 85% in reliable and unreliable channels respectively. In MU-MIMO scenario the throughputs of IEEE 802.11ax are larger than those of IEEE 802.11ac by 263% and 270% in reliable and unreliable channels respectively. Also, as the number of stations increases, the advantage of IEEE 802.11ax in terms of the access delay also increases.

Interference-Aware Adaptive Beam Alignment for Hyper-Dense IEEE 802.11ax Internet-of-Things Networks

“…Figures 9 and 10 show the expected throughput gain of D/UL MU transmission based on (3), (4), and (5) varying BSR, MCS level, and the number of interfering STAs. Note that the physical data rate values for calculating the throughput with various numbers of STAs and MCS level are referenced in [17]. The elongated delay issue caused by the neighboring STAs results in time loss for data transmission and reception of STA as shown in Figures 7 and 8.…”

“…For example, the authors of [16] proposed a scheduling scheme in IEEE 802.11ax with TWT to efficiently handle MU transmissions and multi-AP cooperation. The authors in [17] explored several new IEEE 802.11ax UL scheduling mechanisms and compared them among the maximum throughput of MU. They conducted evaluations of MIMO and OFDMA transmissions in IEEE 802.11ax against the carrier-sense multiple access with collision avoidance (CSMA/CA) MAC of IEEE 802.11ac with the SU and MU modes for various numbers of STAs scenarios in both reliable and unreliable channel environments.…”

IEEE 802.11ax OFDMA Resource Allocation with Frequency-Selective Fading

“…Various schedulers for 802.11ax have been designed and investigated under different channel and traffic conditions to use the 802.11ax capabilities fully. In [ 20 ], multi-user uplink transmissions are considered. It is shown that 802.11ax outperforms 802.11ac in terms of throughput and latency.…”

Interference-Aware Adaptive Beam Alignment for Hyper-Dense IEEE 802.11ax Internet-of-Things Networks

“…For example, the authors of [ 16 ] proposed a scheduling scheme in IEEE 802.11ax with TWT to efficiently handle MU transmissions and multi-AP cooperation. The authors in [ 17 ] explored several new IEEE 802.11ax UL scheduling mechanisms and compared them among the maximum throughput of MU. They conducted evaluations of MIMO and OFDMA transmissions in IEEE 802.11ax against the carrier-sense multiple access with collision avoidance (CSMA/CA) MAC of IEEE 802.11ac with the SU and MU modes for various numbers of STAs scenarios in both reliable and unreliable channel environments.…”

“…Figure 9 and Figure 10 show the expected throughput gain of D/UL MU transmission based on (3), (4), and (5) varying BSR, MCS level, and the number of interfering STAs. Note that the physical data rate values for calculating the throughput with various numbers of STAs and MCS level are referenced in [ 17 ]. The elongated delay issue caused by the neighboring STAs results in time loss for data transmission and reception of STA as shown in Figure 7 and Figure 8 .…”