802.11 Standards and Amendments
Standards map
802.11 defines the MAC/PHY. Legacy: 802.11b (2.4 GHz, DSSS, up to 11 Mbps), 802.11a (5 GHz, OFDM, up to 54 Mbps), 802.11g (2.4 GHz, OFDM, 54 Mbps). 802.11n (Wi-Fi 4) added MIMO, 40 MHz channels, and both bands. 802.11ac (Wi-Fi 5) is 5 GHz only, adds 80/160 MHz, downlink MU-MIMO (Wave 2), and higher MCS. 802.11ax (Wi-Fi 6) works in 2.4/5 GHz and adds OFDMA, uplink and downlink MU-MIMO, BSS coloring, and target wake time; 6 GHz operation is Wi-Fi 6E. Key amendments: 802.11i (RSNA/WPA2), 802.11e/WMM (QoS), 802.11k (neighbor reports), 802.11v (BSS transition management), 802.11r (fast BSS transition), 802.11w (protected management frames).
Traps
802.11ac is not a 2.4 GHz standard; 802.11ax is not "only 6 GHz." 802.11k does not perform the roam; it supplies neighbor information. 802.11r speeds reauthentication but does not replace 802.11k/v. WPA3 relies on 802.11w PMF, so PMF cannot be "disabled everywhere" in a WPA3 design. Do not confuse an MCS index with a fixed data rate-it depends on channel width, spatial streams, and guard interval.
Worked example
A requirement for "more efficient high-density stadium traffic and uplink multi-user" points to 802.11ax, not 802.11ac. If the same requirement adds "6 GHz channels," the answer is Wi-Fi 6E/802.11ax in 6 GHz, not a new PHY amendment.