What 802.11ax Changes For Embedded Design
OFDMA Changes How the Channel is Used
With Wi-Fi 5, the AP hands the channel to one device at a time. With environments that have 30 sensors all trying to push data on a fixed schedule, you get conflicts, backoffs, and retries. The channel sits partially idle while devices wait their turn.
Wi-Fi 6 introduces OFDMA, Orthogonal Frequency-Division Multiple Access, which lets the AP subdivide the channel into units and serve multiple devices simultaneously in a single transmission window. Your 30-sensor environment doesn't hinder anymore as the AP schedules them together. You get better airtime utilization without increasing transmit power or antenna count.
Target Wake Time Reduces the Power in Battery-Constrained Nodes
Target Wake Time (TWT) lets a device share a specific schedule with the AP for when it wakes up and communicates. Between those windows, the radio sleeps. For a battery-powered sensor on a 3-year deployment cycle, this matters more than peak throughput ever will. You're not trying to stream video, you're trying to push 200 bytes of data every 30 seconds without replacing a CR2032 battery every six months.
BSS Coloring Reduces Interference Handling Overhead
In a dense deployment, like a large warehouse with multiple Aps, Wi-Fi 5 devices that overhear a neighboring BSS defer, even when the signal is weak enough that it shouldn't matter. Wi-Fi 6 adds a color code to each BSS, so devices can distinguish “my AP” from “not my AP” and avoid backing off unnecessarily. Less deferral means more efficient use of the channel across the whole floor.
