IEEE 802.11 (legacy mode)

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Wi-Fi generations
Gen. Vi-
sual 		IEEE
standard 		Adopt. Link rate
(Mbit/s) 		RF
(GHz)
Wi-Fi 1 — 802.11 1997 1–2 2.4
Wi-Fi 2 — 802.11b 1999 1–11 2.4
Wi-Fi 3 — 802.11a 1999 6–54 5
802.11g 2003 2.4
Wi-Fi 4
 802.11n 2009 6.5–600 2.4, 5
Wi-Fi 5
 802.11ac 2013 6.5–6933 5[a]
Wi-Fi 6
802.11ax
 2021 0.4–9608 2.4, 5
Wi-Fi 6E[b]
 6
Wi-Fi 7
802.11be
 2024[c] 0.4–46G 2.4, 5, 6
Wi-Fi 8[1][2] — 802.11bn 100G 2.4, 5, 6

IEEE 802.11 (legacy mode) – or more correctly IEEE 802.11-1997 or IEEE 802.11-1999 – refers to the original version of the IEEE 802.11 wireless networking standard released in 1997 and clarified in 1999. Most of the protocols described by this early version are rarely used today.

Description

It specified two raw

Industrial Scientific Medical frequency band at 2.4 GHz. IR remained a part of the standard until IEEE 802.11-2016, but was never implemented.[citation needed
]

The original standard also defines carrier sense 0 access with collision avoidance (CSMA/CA) as the medium access method. A significant percentage of the available raw channel capacity is sacrificed (via the CSMA/CA mechanisms) in order to improve the reliability of data transmissions under diverse and adverse environmental conditions.

IEEE 802.11-1999 also introduced the binary time unit TU defined as 1024 μs.[3]

At least seven different, somewhat-interoperable, commercial products appeared using the original specification, from companies like

Rangelan2
). A weakness of this original specification was that it offered so many choices that interoperability was sometimes challenging to realize. It is really more of a "beta specification" than a rigid specification, initially allowing individual product vendors the flexibility to differentiate their products but with little to no inter-vendor interoperability.

The DSSS version of legacy 802.11 was rapidly supplemented (and popularized) by the

802.11b amendment in 1999, which increased the bit rate to 11 Mbit/s. Widespread adoption of 802.11 networks only occurred after the release of 802.11b which resulted in multiple interoperable products becoming available from multiple vendors. Consequently, comparatively few networks were implemented on the 802.11-1997 standard.[citation needed
]

Comparison

802.11 network standards
Frequency
range,
or type 		PHY Protocol Release
date[4] 		Freq­uency Bandwidth Stream
data rate[5] 		Max.
MIMO streams 		Modulation Approx. range
In­door Out­door
(GHz) (MHz) (Mbit/s)
1–7 GHz DSSS[6], 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[6] 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][7] 		? ?
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)[8]
802.11bd December 2022 5.9, 60 500 m 1,000 m (3,300 ft)
ERP-OFDM[9] 802.11g June 2003 2.4 38 m (125 ft) 140 m (460 ft)
HT-OFDM[10] 802.11n
(Wi-Fi 4) 		October 2009 2.4, 5 20 Up to 288.8[D] 4
QAM
) 		70 m (230 ft) 250 m (820 ft)[11]
40 Up to 600[D]
VHT-OFDM[10] 802.11ac
(Wi-Fi 5) 		December 2013 5 20 Up to 693[D] 8 DL
QAM
) 		35 m (115 ft)[12] ?
40 Up to 1600[D]
80 Up to 3467[D]
160 Up to 6933[D]
HE-OFDMA
802.11ax
(Wi-Fi 6,
Wi-Fi 6E
) 		May 2021 2.4, 5, 6 20 Up to 1147[E] 8 UL/DL
QAM
) 		30 m (98 ft) 120 m (390 ft)[F]
40 Up to 2294[E]
80 Up to 5.5 Gbit/s[E]
80+80 Up to 11.0 Gbit/s[E]
EHT-OFDMA
802.11be
(Wi-Fi 7
) 		Sep 2024
(est.) 		2.4, 5, 6 80 Up to 11.5 Gbit/s[E] 16 UL/DL
QAM
) 		30 m (98 ft) 120 m (390 ft)[F]
160
(80+80) 		Up to 23 Gbit/s[E]
240
(160+80) 		Up to 35 Gbit/s[E]
320
(160+160) 		Up to 46.1 Gbit/s[E]
UHR 802.11bn
(Wi-Fi 8) 		May 2028
(est.) 		2.4, 5, 6,
42, 60, 71 		320 Up to
100000
(100 Gbit/s) 		16 Multi-link
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[13] 802.11ad December 2012 60 2160
(2.16 GHz) 		Up to 8085[14]
(8 Gbit/s) 		— OFDM,[A] single carrier, low-power single carrier[A] 3.3 m (11 ft)[15] ?
802.11aj
 April 2018 60[H] 1080[16] Up to 3754
(3.75 Gbit/s) 		— single carrier, low-power single carrier[A] ? ?
CMMG
802.11aj
 April 2018 45[H] 540,
1080 		Up to 15015[17]
(15 Gbit/s) 		4[18] OFDM, single carrier ? ?
EDMG[19] 802.11ay July 2021 60 Up to 8640
(8.64 GHz) 		Up to 303336[20]
(303 Gbit/s) 		8 OFDM, single carrier 10 m (33 ft) 100 m (328 ft)
Sub 1 GHz (
IoT
) 		TVHT[21] 802.11af February 2014 0.054–
0.79 		6, 7, 8 Up to 568.9[22] 4 MIMO-OFDM ? ?
S1G[21] 802.11ah May 2017 0.7, 0.8,
0.9 		1–16 Up to 8.67[23]
(@2 MHz) 		4 ? ?
Light
(Li-Fi) 		LC
(
VLC/OWC
) 		802.11bb December 2023
(est.) 		800–1000 nm 20 Up to 9.6 Gbit/s — O-
OFDM
 ? ?
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 6757[D] DSSS, OFDM
802.11-2020 (802.11md) December 2020 2.4, 5, 60 Up to 866.7 or 6757[D] DSSS, OFDM
802.11me September 2024
(est.) 		2.4, 5, 6, 60 Up to 9608 or 303336 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. ^
    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

  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 operate in 6 GHz. Wi-Fi 6E offers the features and capabilities of Wi-Fi 6 extended into the 6 GHz band.
  3. ^ The Wi-Fi Alliance began certifying Wi-Fi 7 devices in 2024, but as of January 2025 the IEEE standard 802.11be is yet to be ratified.

References

  1. doi:10.1109/MCOM.003.2200037
    . Retrieved 2024-05-21.
  2. arXiv:2303.10442
    .
  3. ISBN 9780131014060. 0131014064. Retrieved 2015-10-27. {{cite book}}: |work= ignored (help
    )
  4. ^ "Official IEEE 802.11 working group project timelines". January 26, 2017. Retrieved 2017-02-12.
  5. ^ "Wi-Fi CERTIFIED n: Longer-Range, Faster-Throughput, Multimedia-Grade Wi-Fi Networks" (PDF). Wi-Fi Alliance. September 2009.
  6. ^
    arXiv:1307.2661
    .
  7. ^ "The complete family of wireless LAN standards: 802.11 a, b, g, j, n" (PDF).
  8. ^ The Physical Layer of the IEEE 802.11p WAVE Communication Standard: The Specifications and Challenges (PDF). World Congress on Engineering and Computer Science. 2014.
  9. ^ 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. (n.d.). doi:10.1109/ieeestd.2003.94282
  10. ^ a b "Wi-Fi Capacity Analysis for 802.11ac and 802.11n: Theory & Practice" (PDF).
  11. ^ Belanger, Phil; Biba, Ken (2007-05-31). "802.11n Delivers Better Range". Wi-Fi Planet. Archived from the original on 2008-11-24.
  12. ^ "IEEE 802.11ac: What Does it Mean for Test?" (PDF). LitePoint. October 2013. Archived from the original (PDF) on 2014-08-16.
  13. doi:10.1109/IEEESTD.2018.8345727
    .
  14. ^ "802.11ad – WLAN at 60 GHz: A Technology Introduction" (PDF). Rohde & Schwarz GmbH. November 21, 2013. p. 14.
  15. ^ "Connect802 – 802.11ac Discussion". www.connect802.com.
  16. ^ "Understanding IEEE 802.11ad Physical Layer and Measurement Challenges" (PDF).
  17. ^ "802.11aj Press Release".
  18. doi:10.1587/transcom.2017ISI0004
    .
  19. ^ "IEEE 802.11ay: 1st real standard for Broadband Wireless Access (BWA) via mmWave – Technology Blog". techblog.comsoc.org.
  20. ^ "P802.11 Wireless LANs". IEEE. pp. 2, 3. Archived from the original on 2017-12-06. Retrieved Dec 6, 2017.
  21. ^ a b "802.11 Alternate PHYs A whitepaper by Ayman Mukaddam" (PDF).
  22. ^ "TGaf PHY proposal". IEEE P802.11. 2012-07-10. Retrieved 2013-12-29.
  23. doi:10.13052/jicts2245-800X.115
    .

Further reading
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