The IEEE working group formed to design the next-generation of Wi-Fi, which works more efficiently in crowded networks. Expected in 2019, earlier 802.11 devices can detect and bypass 802.11ax packets.
Whereas previous 802.11 standards support one uplink stream at a time from a client to an access point (AP), 802.11ax handles several users simultaneously. 11ax uses the same channel bandwidths as 11ac but with more subdivisions, and unlike 11ac, which is 5 GHz only, 11ax operates in both 2.4 GHz and 5 GHz bands. It also supports modulation 1024QAM (four times 11ac's 256QAM) as well as two multiuser uplink and downlink transmission methods (MU-MIMO and OFDMA). See 802.11ac