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Wi-Fi 6

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Wi-Fi 6
Icon used by the Wi-Fi Alliance for Wi-Fi 6
Introduced1 September 2020; 5 years ago (2020-09-01)
Compatible hardwarePersonal computers, gaming consoles, smart devices, televisions, printers, security cameras
Wi-Fi generations
Gen.[1] IEEE
standard 		Adopt. Link rate
(Mbit/s) 		2.4 GHz 5 GHz 6 GHz
802.11 1997 1–2 Yes
802.11b 1999 1–11 Yes
802.11a 1999 6–54 Yes
802.11g 2003 Yes
Wi-Fi 4 802.11n 2009 6.5–600 Yes Yes
Wi-Fi 5 802.11ac 2013 6.5–6,933 Yes[a]
Wi-Fi 6 802.11ax 2021 0.4–9,608 Yes Yes
Wi-Fi 6E[b] Yes Yes Yes
Wi-Fi 7 802.11be 2024 0.4–23,059 Yes Yes Yes
Wi-Fi 8[2][3] 802.11bn 100,000[4] Yes Yes Yes

IEEE 802.11ax-2021[5] or 802.11ax, is an IEEE standard from the Wi-Fi Alliance, for wireless networks (WLANs). The standard is marketed as Wi-Fi 6.[6] It operates in the 2.4 GHz and 5 GHz bands,[7] with an extended version, Wi-Fi 6E, that adds the 6 GHz band.[8] It is an upgrade from Wi-Fi 5 (IEEE 802.11ac), with improvements for better performance in crowded places. Wi-Fi 6 covers frequencies in license-exempt ISM bands, including the commonly used 2.4 GHz and 5 GHz, as well as the broader 6 GHz band (for WiFi 6E).[9]

This standard aims to boost throughput[c] in crowded places like offices and malls. Though the nominal data rate is only 37%[10] higher than that of 802.11ac, the throughput increases by at least four times,[11] making it more efficient and reducing latency by 75%.[12] The quintupling of overall throughput is made possible by higher spectral efficiency.

802.11ax Wi-Fi has a main feature called OFDMA, similar to how cellular common-carrier networks work.[10] This brings better spectrum use, improved power control to avoid interference, and enhancements like 1024‑QAM, MIMO and MU-MIMO for faster speeds. There are also reliability improvements such as lower power consumption and security protocols like Target Wake Time and WPA3.

The 802.11ax standard was approved on September 1, 2020, with Draft 8 getting 95% approval. Subsequently, on February 1, 2021, the standard received official endorsement from the IEEE Standards Board.[13]

Rate set

[edit]
Modulation and coding schemes
MCS
index
[i] 		Modulation
type 		Coding
rate 		Data rate (Mbit/s)[ii]
Channel width (MHz)
20 40 80 160
Guard Interval (μs)
1.6 0.8 1.6 0.8 1.6 0.8 1.6 0.8
0 BPSK 1/2 8 8.6 16 17.2 34 36.0 68 72
1 QPSK 1/2 16 17.2 33 34.4 68 72.1 136 144
2 QPSK 3/4 24 25.8 49 51.6 102 108.1 204 216
3 16-QAM 1/2 33 34.4 65 68.8 136 144.1 272 288
4 16-QAM 3/4 49 51.6 98 103.2 204 216.2 408 432
5 64-QAM 2/3 65 68.8 130 137.6 272 288.2 544 576
6 64-QAM 3/4 73 77.4 146 154.9 306 324.4 613 649
7 64-QAM 5/6 81 86.0 163 172.1 340 360.3 681 721
8 256-QAM 3/4 98 103.2 195 206.5 408 432.4 817 865
9 256-QAM 5/6 108 114.7 217 229.4 453 480.4 907 961
10 1024-QAM 3/4 122 129.0 244 258.1 510 540.4 1021 1081
11 1024-QAM 5/6 135 143.4 271 286.8 567 600.5 1134 1201

Notes

  1. ^ MCS 9 is not applicable to all combinations of channel width and spatial stream count.
  2. ^ Per spatial stream.

OFDMA

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In 802.11ac (802.11's previous amendment), multi-user MIMO was introduced, which is a spatial multiplexing technique. MU-MIMO allows the access point to form beams towards each client, while transmitting information simultaneously. By doing so, the interference between clients is reduced, and the overall throughput is increased, since multiple clients can receive data simultaneously.

With 802.11ax, a similar multiplexing is introduced in the frequency-division multiplexing: OFDMA. With OFDMA, multiple clients are assigned to different Resource Units in the available spectrum. By doing so, an 80 MHz channel can be split into multiple Resource Units, so that multiple clients receive different types of data over the same spectrum, simultaneously.

To support OFDMA, 802.11ax needs four times as many subcarriers as 802.11ac. Specifically, for 20, 40, 80, and 160 MHz channels, the 802.11ac standard has, respectively, 64, 128, 256 and 512 subcarriers while the 802.11ax standard has 256, 512, 1024, and 2048 subcarriers. Since the available bandwidths have not changed and the number of subcarriers increases by a factor of four, the subcarrier spacing is reduced by the same factor. This introduces OFDM symbols that are four times longer: in 802.11ac, an OFDM symbol takes 3.2 microseconds to transmit. In 802.11ax, it takes 12.8 microseconds (both without guard intervals).

Technical improvements

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The 802.11ax amendment brings several key improvements over 802.11ac. While 802.11ac only uses the 5 GHz band, which is a bit over 700 MHz wide, 802.11ax also allows the use of the 2.4 GHz band of some earlier protocols, less than 100 MHz wide, and the larger 6 GHz band, about 1200 MHz wide.[14] Wi-Fi 6E adds to Wi‑Fi 6 the use of the 6 GHz band and, thereby, channels that are 160 MHz wide without the restrictions of Dynamic Frequency Selection that apply to all 160 MHz channels in the 5 GHz band.[15] The number and selection of channels available depends on the country a given Wi-Fi 6 network operates in.[16] To meet the goal of supporting dense 802.11 deployments, the following features have been approved.

Feature 802.11ac 802.11ax Comment
OFDMA not available Centrally controlled medium access with dynamic assign­ment of 26, 52, 106, 242(?), 484(?), or 996(?) tones per station. Each tone consists of a single subcarrier of 78.125 kHz bandwidth. Therefore, a single OFDMA transmission is between 2.03125 MHz and ca. 80 MHz wide. OFDMA segregates the spectrum in time-frequency resource units (RUs). A central coordinating entity (the AP in 802.11ax) assigns RUs for reception or transmission to associated stations. Through the central scheduling of the RUs, contention overhead can be avoided, which increases efficiency in scenarios of dense deployments.
Multi-user MIMO (MU-MIMO) Available in Downlink direction Available in Downlink and Uplink direction With downlink MU-MIMO an AP may transmit concurrently with multiple stations, and with uplink MU-MIMO an AP may simultaneously receive from multiple stations. Whereas OFDMA separates receivers to different RUs, with MU-MIMO the devices are separated into different spatial streams. In 802.11ax, MU-MIMO and OFDMA can be used simultaneously. To enable uplink MU transmissions, the AP transmits a new control frame (Trigger) which contains scheduling information (RU allocations for stations, and the modulation and coding scheme (MCS) that shall be used for each station). Furthermore, a Trigger also provides synchronization for an uplink transmission, since the transmission starts SIFS after the end of a Trigger.
Trigger-based Random Access not available Allows performing UL OFDMA transmissions by stations which are not allocated RUs directly In a Trigger frame, the AP specifies scheduling information about subsequent UL MU transmission. However, several RUs can be assigned for random access. Stations which are not assigned RUs directly can perform transmissions within RUs assigned for random access. To reduce collision probability (i.e. situation when two or more stations select the same RU for transmission), the 802.11ax amendment specifies a special OFDMA back-off procedure. Random access is favorable for transmitting buffer status reports when the AP has no information about pending UL traffic at a station.
Spatial frequency reuse not available Coloring enables devices to differentiate transmissions in their own network from trans­missions in neighboring net­works. Adaptive power and sensitivity thresholds allow dynamically adjusting transmit power and signal detection threshold to increase spatial reuse. Without spatial reuse capabilities devices refuse transmitting concurrently with transmissions in neighboring networks. With basic service set coloring (BSS coloring), a wireless transmission is marked at its very beginning, helping surrounding devices to decide if a simultaneous use of the wireless medium is permissible. A station is allowed to consider the wireless medium idle and start a new transmission even if the detected signal level from a neighboring network exceeds the legacy signal detection threshold, provided that the transmit power for the new transmission is appropriately decreased.
NAV Single NAV Dual NAVs In dense deployment scenarios, the NAV value set by a frame from one network may be easily reset by a frame from another network, which leads to misbehavior and collisions. To avoid this, each 802.11ax station will maintain two separate NAVs: One NAV is modified by frames from a network the station is associated with, while the other NAV is modified by frames from overlapping networks.
Target Wake Time (TWT) not available TWT reduces power consumption and medium access contention. TWT is a concept developed in 802.11ah. It allows devices to wake up at times other than the periodic beacon transmission time. Furthermore, the AP may group devices with various TWT periods, thereby reducing the number of devices contending simultaneously for the wireless medium.
Fragmentation Static Dynamic With static fragmentation, all fragments of a data packet are of equal size, except for the last fragment. With dynamic fragmentation, a device may fill available RUs of other opportunities to transmit up to the available maximum duration. Thus, dynamic fragmentation helps reduce overhead.
Guard interval duration 0.4 or 0.8 μs 0.8, 1.6 or 3.2 μs Extended guard interval durations allow for better protection against signal delay spread as it occurs in outdoor environments.
Symbol duration 3.2 μs 12.8 μs Since the subcarrier spacing is reduced by a factor of four, the OFDM symbol duration is increased by a factor of four as well. Extended symbol durations allow for increased efficiency.[17]
Frequency bands 5 GHz only 2.4 and 5 GHz 802.11ac falls back to 802.11n for the 2.4 GHz band.

Comparison

[edit]
802.11 network standards
Frequency
range,
or type 		PHY Protocol Release
date[18] 		Freq­uency band Channel width Stream
data rate[19] 		Max.
MIMO streams 		Modulation Approx. range
In­door Out­door
(GHz) (MHz) (Mbit/s)
1–7 GHz DSSS[20], FHSS[A] 802.11-1997 June 1997 2.4 22 1, 2 — DSSS, FHSS[A] 20 m (66 ft) 100 m (330 ft)
HR/DSSS[20] 802.11b September 1999 2.4 22 1, 2, 5.5, 11 — CCK, DSSS 35 m (115 ft) 140 m (460 ft)
OFDM 802.11a September 1999 5 5, 10, 20 6, 9, 12, 18, 24, 36, 48, 54
(for 20 MHz bandwidth,
divide by 2 and 4 for 10 and 5 MHz) 		— OFDM 35 m (115 ft) 120 m (390 ft)
802.11j November 2004 4.9, 5.0
[B][21] 		? ?
802.11y November 2008 3.7[C] ? 5,000 m (16,000 ft)[C]
802.11p July 2010 5.9 200 m 1,000 m (3,300 ft)[22]
802.11bd December 2022 5.9, 60 500 m 1,000 m (3,300 ft)
ERP-OFDM[23] 802.11g June 2003 2.4 38 m (125 ft) 140 m (460 ft)
HT-OFDM[24] 802.11n
(Wi-Fi 4) 		October 2009 2.4, 5 20 Up to 288.8[D] 4 MIMO-OFDM
(64-QAM) 		70 m (230 ft) 250 m (820 ft)[25]
40 Up to 600[D]
VHT-OFDM[24] 802.11ac
(Wi-Fi 5) 		December 2013 5 20 Up to 693[D] 8 DL
MU-MIMO OFDM
(256-QAM) 		35 m (115 ft)[26] ?
40 Up to 1,600[D]
80 Up to 3,467[D]
160 Up to 6,933[D]
HE-OFDMA 802.11ax
(Wi-Fi 6,
Wi-Fi 6E) 		May 2021 2.4, 5, 6 20 Up to 1,147[E] 8 UL/DL
MU-MIMO OFDMA
(1024-QAM) 		30 m (98 ft) 120 m (390 ft)[F]
40 Up to 2,294[E]
80 Up to 5,500[E]
80+80 Up to 11,000[E]
EHT-OFDMA 802.11be
(Wi-Fi 7) 		Sep 2024 2.4, 5, 6 80 Up to 5,764[E] 8 UL/DL
MU-MIMO OFDMA
(4096-QAM) 		30 m (98 ft) 120 m (390 ft)[F]
160
(80+80) 		Up to 11,500[E]
240
(160+80) 		Up to 14,282[E]
320
(160+160) 		Up to 23,059[E]
UHR 802.11bn
(Wi-Fi 8) 		May 2028
(est.) 		2.4, 5, 6 320 Up to
23,059
8 Multi-link
MU-MIMO OFDM
(4096-QAM) 		? ?
WUR[G] 802.11ba October 2021 2.4, 5 4, 20 0.0625, 0.25
(62.5 kbit/s, 250 kbit/s) 		— OOK (multi-carrier OOK) ? ?
mmWave
(WiGig) 		DMG[27] 802.11ad December 2012 60 2,160
(2.16 GHz) 		Up to 8,085[28]
(8 Gbit/s) 		— OFDM,[A] single carrier, low-power single carrier[A] 3.3 m (11 ft)[29] ?
802.11aj April 2018 60[H] 1,080[30] Up to 3,754
(3.75 Gbit/s) 		— single carrier, low-power single carrier[A] ? ?
CMMG 802.11aj April 2018 45[H] 540,
1,080 		Up to 15,015[31]
(15 Gbit/s) 		4[32] OFDM, single carrier ? ?
EDMG[33] 802.11ay July 2021 60 Up to 8,640
(8.64 GHz) 		Up to 303,336[34]
(303 Gbit/s) 		8 OFDM, single carrier 10 m (33 ft) 100 m (328 ft)
Sub 1 GHz (IoT) TVHT[35] 802.11af February 2014 0.054–
0.79 		6, 7, 8 Up to 568.9[36] 4 MIMO-OFDM ? ?
S1G[35] 802.11ah May 2017 0.7, 0.8,
0.9 		1–16 Up to 8.67[37]
(@2 MHz) 		4 ? ?
Light
(Li-Fi) 		LC
(VLC/OWC) 		802.11bb November 2023 800–1000 nm 20 Up to 9.6 Gbit/s — O-OFDM ? ?
IR[A]
(IrDA) 		802.11-1997 June 1997 850–900 nm ? 1, 2 — PPM[A] ? ?
802.11 Standard rollups
  802.11-2007 (802.11ma) March 2007 2.4, 5 Up to 54 DSSS, OFDM
802.11-2012 (802.11mb) March 2012 2.4, 5 Up to 150[D] DSSS, OFDM
802.11-2016 (802.11mc) December 2016 2.4, 5, 60 Up to 866.7 or 6,757[D] DSSS, OFDM
802.11-2020 (802.11md) December 2020 2.4, 5, 60 Up to 866.7 or 6,757[D] DSSS, OFDM
802.11-2024 (802.11me) September 2024 2.4, 5, 6, 60 Up to 9,608 or 303,336 DSSS, OFDM
  1. ^ a b c d e f g This is obsolete, and support for this might be subject to removal in a future revision of the standard
  2. ^ For Japanese regulation.
  3. ^ a b IEEE 802.11y-2008 extended operation of 802.11a to the licensed 3.7 GHz band. Increased power limits allow a range up to 5,000 m. As of 2009, it is only being licensed in the United States by the FCC.
  4. ^ a b c d e f g h i Based on short guard interval; standard guard interval is ~10% slower. Rates vary widely based on distance, obstructions, and interference.
  5. ^ a b c d e f g h For single-user cases only, based on default guard interval which is 0.8 microseconds. Since multi-user via OFDMA has become available for 802.11ax, these may decrease. Also, these theoretical values depend on the link distance, whether the link is line-of-sight or not, interferences and the multi-path components in the environment.
  6. ^ a b The default guard interval is 0.8 microseconds. However, 802.11ax extended the maximum available guard interval to 3.2 microseconds, in order to support Outdoor communications, where the maximum possible propagation delay is larger compared to Indoor environments.
  7. ^ Wake-up Radio (WUR) Operation.
  8. ^ a b For Chinese regulation.

Notes

[edit]
  1. ^ 802.11ac only specifies operation in the 5 GHz band. Operation in the 2.4 GHz band is specified by 802.11n.
  2. ^ Wi-Fi 6E is the industry name that identifies Wi-Fi devices that also operate in 6 GHz. Wi-Fi 6E offers the features and capabilities of Wi-Fi 6 extended into the 6 GHz band.
  3. ^ Throughput-per-area, as defined by IEEE, is the ratio of the total network throughput to the network area.[10]

References

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  1. ^ "The Evolution of Wi-Fi Technology and Standards". IEEE. 2023-05-16. Retrieved 2025-08-07.
  2. ^ Reshef, Ehud; Cordeiro, Carlos (2023). "Future Directions for Wi-Fi 8 and Beyond". IEEE Communications Magazine. 60 (10). IEEE: 50–55. doi:10.1109/MCOM.003.2200037.
  3. ^ Giordano, Lorenzo; Geraci, Giovanni; Carrascosa, Marc; Bellalta, Boris (November 21, 2023). "What Will Wi-Fi 8 Be? A Primer on IEEE 802.11bn Ultra High Reliability". IEEE Communications Magazine. 62 (8): 126. arXiv:2303.10442. Bibcode:2024IComM..62h.126G. doi:10.1109/MCOM.001.2300728.
  4. ^ Geraci, Giovanni; Meneghello, Francesca; Wilhelmi, Francesc; Lopez-Perez, David; Val, Iñaki; Lorenzo Galati Giordano; Cordeiro, Carlos; Ghosh, Monisha; Knightly, Edward; Bellalta, Boris (2025). "Wi-Fi: Twenty-Five Years and Counting". arXiv:2507.09613 [cs.NI].
  5. ^ "IEEE 802.11ax-2021". IEEE Standards Association. Archived from the original on 2022-05-22. Retrieved 2025-09-17.
  6. ^ "Wi-Fi® (MAC/PHY)". Wi-Fi Alliance. Retrieved 2025-09-17.
  7. ^ "Generational Wi-Fi User Guide" (PDF). Wi-Fi Alliance. October 2018. Retrieved 22 March 2021.
  8. ^ "Wi-Fi 6E expands Wi-Fi into 6 GHz" (PDF). Wi-Fi Alliance. January 2021. Retrieved 22 March 2021.
  9. ^ "FCC Opens 6 GHz Band to Wi-Fi and Other Unlicensed Uses". www.fcc.gov. 24 April 2020. Retrieved 23 March 2021.
  10. ^ a b c Khorov, Evgeny; Kiryanov, Anton; Lyakhov, Andrey; Bianchi, Giuseppe (2019). "A Tutorial on IEEE 802.11ax High Efficiency WLANs". IEEE Communications Surveys & Tutorials. 21 (1): 197–216. doi:10.1109/COMST.2018.2871099.
  11. ^ Aboul-Magd, Osama (17 March 2014). "802.11 HEW SG Proposed PAR" (DOCX). IEEE. Archived from the original on 7 April 2014. Retrieved 22 March 2021.
  12. ^ Goodwins, Rupert (3 October 2018). "Next-generation 802.11ax wi-fi: Dense, fast, delayed". ZDNet. Retrieved 23 March 2021.
  13. ^ "IEEE 802.11, The Working Group Setting the Standards for Wireless LANs". www.ieee802.org. Retrieved 2022-01-07.
  14. ^ Aboul-Magd, Osama (2014-01-24). "P802.11ax" (PDF). IEEE-SA. Archived (PDF) from the original on 2014-10-10. Retrieved 2017-01-14. 2 page PDF download
  15. ^ "Wi-Fi CERTIFIED 6 | Wi-Fi Alliance".
  16. ^ "Wi-Fi 6E and 6 GHz Update" (PDF). www.wi-fi.org. 2021-03-11.
  17. ^ Porat, Ron; Fischer, Matthew; Venkateswaran, Sriram; et al. (2015-01-12). "Payload Symbol Size for 11ax". IEEE P802.11. Retrieved 2017-01-14.
  18. ^ "Official IEEE 802.11 working group project timelines". January 26, 2017. Retrieved 2017-02-12.
  19. ^ "Wi-Fi CERTIFIED n: Longer-Range, Faster-Throughput, Multimedia-Grade Wi-Fi Networks" (PDF). Wi-Fi Alliance. September 2009.
  20. ^ a b Banerji, Sourangsu; Chowdhury, Rahul Singha (2013). "On IEEE 802.11: Wireless LAN Technology". arXiv:1307.2661 [cs.NI].
  21. ^ "The complete family of wireless LAN standards: 802.11 a, b, g, j, n" (PDF).
  22. ^ The Physical Layer of the IEEE 802.11p WAVE Communication Standard: The Specifications and Challenges (PDF). World Congress on Engineering and Computer Science. 2014.
  23. ^ IEEE Standard for Information Technology- Telecommunications and Information Exchange Between Systems- Local and Metropolitan Area Networks- Specific Requirements Part II: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. doi:10.1109/ieeestd.2003.94282. ISBN 0-7381-3701-4.
  24. ^ a b "Wi-Fi Capacity Analysis for 802.11ac and 802.11n: Theory & Practice" (PDF).
  25. ^ Belanger, Phil; Biba, Ken (2007-05-31). "802.11n Delivers Better Range". Wi-Fi Planet. Archived from the original on 2008-11-24.
  26. ^ "IEEE 802.11ac: What Does it Mean for Test?" (PDF). LitePoint. October 2013. Archived from the original (PDF) on 2014-08-16.
  27. ^ "IEEE Standard for Information Technology". IEEE STD 802.11aj-2018. April 2018. doi:10.1109/IEEESTD.2018.8345727. ISBN 978-1-5044-4633-4.
  28. ^ "802.11ad – WLAN at 60 GHz: A Technology Introduction" (PDF). Rohde & Schwarz GmbH. November 21, 2013. p. 14.
  29. ^ "Connect802 – 802.11ac Discussion". www.connect802.com.
  30. ^ "Understanding IEEE 802.11ad Physical Layer and Measurement Challenges" (PDF).
  31. ^ "802.11aj Press Release".
  32. ^ Hong, Wei; He, Shiwen; Wang, Haiming; Yang, Guangqi; Huang, Yongming; Chen, Jixing; Zhou, Jianyi; Zhu, Xiaowei; Zhang, Nianzhu; Zhai, Jianfeng; Yang, Luxi; Jiang, Zhihao; Yu, Chao (2018). "An Overview of China Millimeter-Wave Multiple Gigabit Wireless Local Area Network System". IEICE Transactions on Communications. E101.B (2): 262–276. Bibcode:2018IEITC.101..262H. doi:10.1587/transcom.2017ISI0004.
  33. ^ "IEEE 802.11ay: 1st real standard for Broadband Wireless Access (BWA) via mmWave – Technology Blog". techblog.comsoc.org.
  34. ^ "P802.11 Wireless LANs". IEEE. pp. 2, 3. Archived from the original on 2017-12-06. Retrieved Dec 6, 2017.
  35. ^ a b "802.11 Alternate PHYs A whitepaper by Ayman Mukaddam" (PDF).
  36. ^ "TGaf PHY proposal". IEEE P802.11. 2012-07-10. Retrieved 2013-12-29.
  37. ^ Sun, Weiping; Choi, Munhwan; Choi, Sunghyun (July 2013). "IEEE 802.11ah: A Long Range 802.11 WLAN at Sub 1 GHz" (PDF). Journal of ICT Standardization. 1 (1): 83–108. doi:10.13052/jicts2245-800X.115.
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