IEEE 802.11ax

802.11 ax is a type of WLAN in the IEEE 802.11 set of types of WLANs. It is designed to improve overall spectral efficiency. It is still in a very early stage of development, but is predicted to have a top speed of around 10 Gbit/s^[1] (as tested by Huawei), it works in 2.4 and/or 5 GHz, in addition to MIMO and MU-MIMO it introduces OFDMA technique to improve spectral efficiency and also higher order 1024 QAM modulation support for better throughputs. It is due to be publicly released in 2019.

Rate Set

Modulation and coding schemes for single spatial stream

MCS index[lower-alpha 1]	Modulation type	Coding rate	Data rate (in Mbit/s)[lower-alpha 2]
			20 MHz channels		40 MHz channels		80 MHz channels		160 MHz channels
			1600 ns GI[lower-alpha 3]	800 ns GI	1600 ns GI	800 ns GI	1600 ns GI	800 ns GI	1600 ns GI	800 ns GI
0	BPSK	1/2	4	4	8	9	17	18	34	36
1	QPSK	1/2	16	17	33	34	68	72	136	144
2	QPSK	3/4	24	26	49	52	102	108	204	216
3	16-QAM	1/2	33	34	65	69	136	144	272	282
4	16-QAM	3/4	49	52	98	103	204	216	408	432
5	64-QAM	2/3	65	69	130	138	272	288	544	576
6	64-QAM	3/4	73	77	146	155	306	324	613	649
7	64-QAM	5/6	81	86	163	172	340	360	681	721
8	256-QAM	3/4	98	103	195	207	408	432	817	865
9	256-QAM	5/6	108	115	217	229	453	480	907	961
10	1024-QAM	3/4	122	129	244	258	510	540	1021	1081
11	1024-QAM	5/6	135	143	271	287	567	600	1134	1201

Notes

1. MCS 9 is not applicable to all channel width/spatial stream combinations.
2. A second stream doubles the theoretical data rate, a third one triples it, etc.
3. GI stands for the guard interval.

References

1. "What is 802.11ax WiFi, and will it really deliver 10Gbps? (updated) | ExtremeTech". ExtremeTech. Retrieved 2016-01-01.

Further reading

1. "Are you ready for the next chapter of Wi-Fi? Meet 802.11ax"
2. Bellalta, Boris (2015). "IEEE 802.11ax: High-Efficiency WLANs,". arXiv:1501.01496v4.