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

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, en- abling 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 Acceess (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 ac- knowledgment operation settings, where the maximum acknowledgment windows are 64 or 256 respectively. In SU scenario IEEE 802.11ax throughputs outperform IEEE 802.11ac by about 64% and 85% in reliable and unreliable channels respectively. In MU-MIMO scenario IEEE 802.11ax throughputs outperform IEEE 802.11ac by up to 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.Comment: 31 pages, 7 figures. arXiv admin note: substantial text overlap with arXiv:1709.0481

Optimizing TCP Goodput and Delay in next generation IEEE 802.11 (ax) devices

In this paper we suggest three scheduling strategies for the IEEE 802.11ax transmis- sion of DL unidirectional TCP data from the Access Point to stations. Two strategies are based on the Single User operation mode and one is based on the Multi User operation mode, using Multi User Multiple-Input-Multiple-Output (MU-MIMO) and OFDMA. We measure the Goodput of the system as a function of the time intervals over which these Goodputs are received in all three strategies. For up to 8 stations the MU strategy outperforms the SU. For 16 and 32 stations it is not clear whether MU outperforms SU or vice versa. For 64 stations the SU strategies outperform the MU significantly. We also checked the influence of the Delayed Acks feature on the received Goodputs and found that this feature has significance only when the TCP data segments are relatively short.Comment: 37 pages, 9 figure

Advanced IEEE 802.11ax TCP aware scheduling under unreliable channels

In this paper we suggest advanced IEEE 802.11ax TCP-aware scheduling strategies for optimizing the AP operation under transmission of unidirectional TCP traffic. Our scheduling strategies optimize the performance using the capability for Multi User transmissions over the Uplink, first introduced in IEEE 802.11ax, together with Multi User transmissions over the Downlink. They are based on Transmission Opportunities (TXOP) and we suggest three scheduling strategies determining the TXOP formation parameters. In one of the strategies one can control the achieved Goodput vs. the delay. We also assume saturated WiFi transmission queues. We show that with minimal Goodput degradation one can avoid considerable delays.Comment: 35 pages , 12 figures. arXiv admin note: text overlap with arXiv:1711.0402