IEEE 802.11ax: High-Efficiency WLAN (Superfast Wi-Fi)

This article describes the features of the IEEE 802.11ax WLAN standard, also known as High-Efficiency WLAN (HEW) or superfast Wi-Fi. This standard, IEEE 802.11ax, is an amendment to the earlier IEEE 802.11ac standard.

It lays out the specifications for both the Physical (PHY) and Medium Access Control (MAC) layers.

Key Features of 802.11ax

Devices compliant with the 802.11ax standard boast the following capabilities:

• Frequency Band: Operates in both the 2.4 GHz and 5 GHz bands.
• Modulation Schemes: Employs MIMO OFDM, along with BPSK, QPSK, 16QAM, and 64QAM.
• Number of Spatial Streams: Supports 1, 2, 3, 4, 5, 6, 7, and 8 spatial streams (following the 802.11ac standard).
• Channel Bandwidth (MHz): Utilizes channel bandwidths of 20, 40, 80, and 160 MHz, and potentially 80+80 MHz (similar to 11ac).
• Advanced Technologies: Incorporates Simultaneous Transmit/Receive (STR), Downlink and Uplink OFDMA, Uplink MU-MIMO, and Dynamic CCA.

Integration with Cellular Technologies

The IEEE 802.11ax standard is expected to be used in conjunction with advanced cellular wireless technologies like LTE and LTE-Advanced.

Ratification

The Wi-Fi Alliance is working towards ratifying the IEEE 802.11ax standard, with a target date of 2019.