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IEEE 802.11b-1999

From Wikipedia, the free encyclopedia
Wireless networking standard
Not to be confused withIEEE 802.11be.
Wi-Fi generations
Gen.[1]IEEE
standard		Adopt.Link rate
(Mbit/s)		RF (GHz)
2.456
Wi-Fi 1802.1119971–2Yes
Wi-Fi 2802.11b19991–11Yes
Wi-Fi 2G802.11a6–54Yes
Wi-Fi 3802.11g2003Yes
Wi-Fi 4802.11n20096.5–600YesYes
Wi-Fi 5802.11ac20136.5–6,933[a]Yes
Wi-Fi 6802.11ax20210.4–9,608YesYes
Wi-Fi 6EYesYesYes
Wi-Fi 7802.11be20240.4–23,059YesYesYes
Wi-Fi 8[2][3][4]802.11bnTBAYesYesYes

IEEE 802.11b-1999 or802.11b is an amendment to theIEEE 802.11wireless networking specification that extends throughput up to 11Mbit/s using the same2.4 GHz band. A related amendment was incorporated into theIEEE 802.11-2007 standard.

802.11 is a set ofIEEE standards that govern wireless networking transmission methods. They are commonly used today in their802.11a, 802.11b,802.11g,802.11n,802.11ac and802.11ax versions to provide wireless connectivity in the home, office and some commercial establishments.

Description

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802.11b has a maximum raw data rate of 11 Mbit/s and uses the sameCSMA/CA media access method defined in the original standard. Due to the CSMA/CA protocol overhead, in practice the maximum 802.11b throughput that an application can achieve is about 5.9 Mbit/s usingTCP and 7.1 Mbit/s usingUDP.

802.11b products appeared on the market in mid-1999, since 802.11b is a direct extension of theDSSS (Direct-sequence spread spectrum) modulation technique defined in the original standard. The AppleiBook was the first mainstream computer sold with optional 802.11b networking. Technically, the 802.11b standard usescomplementary code keying (CCK) as its modulation technique, which uses a specific set of length 8 complementary codes that was originally designed for OFDM[5] but was also suitable for use in 802.11b because of its low autocorrelation properties.[6] The dramatic increase in throughput of 802.11b (compared to the original standard) along with simultaneous substantial price reductions led to the rapid acceptance of 802.11b as the definitive wireless LAN technology as well as to the formation of theWi-Fi Alliance.

802.11b devices suffer interference from other products operating in the 2.4 GHz band. Devices operating in the 2.4 GHz range include:microwave ovens,Bluetooth devices, baby monitors and cordless telephones. Interference issues and user density problems within the 2.4 GHz band have become a major concern and frustration for users.

Code Length bitsModulation
type		Symbol RateBit per SymbolData rate
(Mbit/s)
11-bit Barker codeBPSK11/11 = 111
11-bit Barker codeDBPSK11/11 = 122
8-bit CCKQPSK11/8 = 1.37545.5
8-bit CCKDQPSK11/8 = 1.375811

Range

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802.11b is used in apoint-to-multipoint configuration, wherein anaccess point communicates via anomnidirectional antenna with mobile clients within the range of the access point. Typical range depends on the radio frequency environment, output power and sensitivity of the receiver. Allowable bandwidth is shared across clients in discrete channels. A directional antenna focuses transmit and receive power into a smaller field which reduces interference and increases point-to-point range. Designers of such installations who wish to remain within the law must however be careful about legal limitations oneffective radiated power.[7]

Some 802.11b cards operate at 11 Mbit/s, but scale back to 5.5, then to 2, then to 1 Mbit/s (also known as Adaptive Rate Selection) in order to decrease the rate of re-broadcasts that result from errors.

Channels and frequencies

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802.11b/g channels in 2.4 GHz band
channel to frequency map[8]
Channel Center frequency Frequency deltaChannel widthOverlaps channels
12.412 GHz5 MHz2.401–2.423 GHz2-5
22.417 GHz5 MHz2.406–2.428 GHz1,3-6
32.422 GHz5 MHz2.411–2.433 GHz1–2,4-7
42.427 GHz5 MHz2.416–2.438 GHz1–3,5-8
52.432 GHz5 MHz2.421–2.443 GHz1–4,6-9
62.437 GHz5 MHz2.426–2.448 GHz2–5,7-10
72.442 GHz5 MHz2.431–2.453 GHz3–6,8-11
82.447 GHz5 MHz2.436–2.458 GHz4–7,9-12
92.452 GHz5 MHz2.441–2.463 GHz5–8,10-13
102.457 GHz5 MHz2.446–2.468 GHz6–9,11-13
112.462 GHz5 MHz2.451–2.473 GHz7-10,12-13
122.467 GHz5 MHz2.456–2.478 GHz8-11,13-14
132.472 GHz5 MHz2.461–2.483 GHz9-12, 14
142.484 GHz12 MHz2.473–2.495 GHz12-13
Note: Channel 14 is only allowed in Japan, Channels 12 & 13 are allowed in most parts of the world. More information can be found in theList of WLAN channels.

Comparison

[edit]
802.11 network standards
Frequency
range,
or type		PHYProtocolRelease
date[9]		Freq­uency bandChannel widthStream
data rate[10]		Max.
MIMO streams		ModulationApprox. range
In­doorOut­door
(GHz)(MHz)(Mbit/s)
1–7 GHzDSSS[11],FHSS[A]802.11-1997June 19972.4221, 2N/aDSSS,FHSS[A]20 m (66 ft)100 m (330 ft)
HR/DSSS[11]802.11bSeptember 19992.4221, 2, 5.5, 11N/aCCK, DSSS35 m (115 ft)140 m (460 ft)
OFDM802.11aSeptember 199955, 10, 206, 9, 12, 18, 24, 36, 48, 54
(for 20 MHz bandwidth,
divide by 2 and 4 for 10 and 5 MHz)		N/aOFDM35 m (115 ft)120 m (390 ft)
802.11jNovember 20044.9, 5.0
[B][12]		??
802.11yNovember 20083.7[C]?5,000 m (16,000 ft)[C]
802.11pJuly 20105.9200 m1,000 m (3,300 ft)[13]
802.11bdDecember 20225.9, 60500 m1,000 m (3,300 ft)
ERP-OFDM[14]802.11gJune 20032.438 m (125 ft)140 m (460 ft)
HT-OFDM[15]802.11n
(Wi-Fi 4)		October 20092.4, 520Up to 288.8[D]4MIMO-OFDM
(64-QAM)		70 m (230 ft)250 m (820 ft)[16]
40Up to 600[D]
VHT-OFDM[15]802.11ac
(Wi-Fi 5)		December 2013520Up to 693[D]8DL
MU-MIMOOFDM
(256-QAM)		35 m (115 ft)[17]?
40Up to 1,600[D]
80Up to 3,467[D]
160Up to 6,933[D]
HE-OFDMA802.11ax
(Wi-Fi 6,
Wi-Fi 6E)		May 20212.4, 5, 620Up to 1,147[E]8UL/DL
MU-MIMOOFDMA
(1024-QAM)		30 m (98 ft)120 m (390 ft)[F]
40Up to 2,294[E]
80Up to 5,500[E]
80+80Up to 11,000[E]
EHT-OFDMA802.11be
(Wi-Fi 7)		Sep 20242.4, 5, 680Up to 5,764[E]8UL/DL
MU-MIMOOFDMA
(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]
UHR802.11bn
(Wi-Fi 8)		May 2028
(est.)		2.4, 5, 6320Up to
23,059
8Multi-link
MU-MIMOOFDM
(4096-QAM)		??
WUR[G]802.11baOctober 20212.4, 54, 200.0625, 0.25
(62.5 kbit/s, 250 kbit/s)		N/aOOK (multi-carrier OOK)??
mmWave
(WiGig)		DMG[18]802.11adDecember 2012602,160
(2.16 GHz)		Up to 8,085[19]
(8 Gbit/s)		N/aOFDM,[A] single carrier, low-power single carrier[A]3.3 m (11 ft)[20]?
802.11ajApril 201860[H]1,080[21]Up to 3,754
(3.75 Gbit/s)		N/asingle carrier, low-power single carrier[A]??
CMMG802.11ajApril 201845[H]540,
1,080		Up to 15,015[22]
(15 Gbit/s)		4[23]OFDM, single carrier??
EDMG[24]802.11ayJuly 202160Up to 8,640
(8.64 GHz)		Up to 303,336[25]
(303 Gbit/s)		8OFDM, single carrier10 m (33 ft)100 m (328 ft)
Sub 1 GHz (IoT)TVHT[26]802.11afFebruary 20140.054–
0.79		6, 7, 8Up to 568.9[27]4MIMO-OFDM??
S1G[26]802.11ahMay 20170.7, 0.8,
0.9		1–16Up to 8.67[28]
(@2 MHz)		4??
Light
(Li-Fi)		LC
(VLC/OWC)		802.11bbNovember 2023800–1000 nm20Up to 9.6 Gbit/sN/aO-OFDM??
IR[A]
(IrDA)		802.11-1997June 1997850–900 nm?1, 2N/aPPM[A]??
802.11 Standard rollups
 802.11-2007 (802.11ma)March 20072.4, 5Up to 54DSSS,OFDM
802.11-2012 (802.11mb)March 20122.4, 5Up to 150[D]DSSS,OFDM
802.11-2016 (802.11mc)December 20162.4, 5, 60Up to 866.7 or 6,757[D]DSSS,OFDM
802.11-2020 (802.11md)December 20202.4, 5, 60Up to 866.7 or 6,757[D]DSSS,OFDM
802.11-2024 (802.11me)September 20242.4, 5, 6, 60Up to 9,608 or 303,336DSSS,OFDM
  1. ^abcdefgThis is obsolete, and support for this might be subject to removal in a future revision of the standard
  2. ^For Japanese regulation.
  3. ^abIEEE 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[update], it is only being licensed in the United States by theFCC.
  4. ^abcdefghiBased on shortguard interval; standard guard interval is ~10% slower. Rates vary widely based on distance, obstructions, and interference.
  5. ^abcdefghFor single-user cases only, based on defaultguard interval which is 0.8 microseconds. Since multi-user viaOFDMA 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 themulti-path components in the environment.
  6. ^abThe defaultguard interval is 0.8 microseconds. However, 802.11ax extended the maximum availableguard 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. ^abFor Chinese regulation.

See also

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Notes

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  1. ^802.11ac only specifies operation in the 5 GHz band. Operation in the 2.4 GHz band is specified by 802.11n.

References

[edit]
  1. ^"The Evolution of Wi-Fi Technology and Standards".IEEE. 2023-05-16. Retrieved2025-08-07.
  2. ^Karamyshev, Anton; Levitsky, Ilya; Bankov, Dmitry; Khorov, Evgeny (2025-10-06)."A Tutorial on Wi-Fi 8: The Journey to Ultra High Reliability".Problems of Information Transmission.61 (2):164–210.doi:10.1134/S003294602502005X.
  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. ^Fang, Bradley; Roger, Michael (2025). "Road Rules for Radio: Why Your Wi-Fi Got Better".arXiv:2512.23901 [cs.NI].
  5. ^Van Nee, Richard (November 1996)."OFDM codes for peak-to-average power reduction and error correction".IEEE Globecom. London.
  6. ^Webster, Mark; Andren, Carl; Boer, Jan; Van Nee, Richard (July 1998)."Harris/Lucent TGb Compromise CCK 11Mbps Proposal".IEEE 802.11-98/246a. London.
  7. ^"Code of Federal Regulations, Title 47-Telecommunications, Chapter I-Federal Communications Commission, Part 15-Radio Frequency Devices, Section 15.247"(PDF). 2006-10-01.Archived(PDF) from the original on 2012-09-07. Retrieved2013-06-10.
  8. ^http://download.wcvirtual.com/reference/802%20Channel%20Freq%20Mappings.pdf[permanent dead link]
  9. ^"Official IEEE 802.11 working group project timelines". January 26, 2017. Retrieved2017-02-12.
  10. ^"Wi-Fi CERTIFIED n: Longer-Range, Faster-Throughput, Multimedia-Grade Wi-Fi Networks"(PDF).Wi-Fi Alliance. September 2009.
  11. ^abBanerji, Sourangsu; Chowdhury, Rahul Singha (2013). "On IEEE 802.11: Wireless LAN Technology".arXiv:1307.2661 [cs.NI].
  12. ^"The complete family of wireless LAN standards: 802.11 a, b, g, j, n"(PDF).
  13. ^The Physical Layer of the IEEE 802.11p WAVE Communication Standard: The Specifications and Challenges(PDF). World Congress on Engineering and Computer Science. 2014.
  14. ^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.
  15. ^ab"Wi-Fi Capacity Analysis for 802.11ac and 802.11n: Theory & Practice"(PDF).
  16. ^Belanger, Phil; Biba, Ken (2007-05-31)."802.11n Delivers Better Range".Wi-Fi Planet. Archived fromthe original on 2008-11-24.
  17. ^"IEEE 802.11ac: What Does it Mean for Test?"(PDF).LitePoint. October 2013. Archived fromthe original(PDF) on 2014-08-16.
  18. ^"IEEE Standard for Information Technology".IEEE STD 802.11aj-2018. April 2018.doi:10.1109/IEEESTD.2018.8345727.ISBN 978-1-5044-4633-4.
  19. ^"802.11ad – WLAN at 60 GHz: A Technology Introduction"(PDF). Rohde & Schwarz GmbH. November 21, 2013. p. 14.
  20. ^"Connect802 – 802.11ac Discussion".www.connect802.com.
  21. ^"Understanding IEEE 802.11ad Physical Layer and Measurement Challenges"(PDF).
  22. ^"802.11aj Press Release".
  23. ^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.
  24. ^"IEEE 802.11ay: 1st real standard for Broadband Wireless Access (BWA) via mmWave – Technology Blog".techblog.comsoc.org.
  25. ^"P802.11 Wireless LANs". IEEE. pp. 2, 3. Archived fromthe original on 2017-12-06. RetrievedDec 6, 2017.
  26. ^ab"802.11 Alternate PHYs A whitepaper by Ayman Mukaddam"(PDF).
  27. ^"TGaf PHY proposal". IEEE P802.11. 2012-07-10. Retrieved2013-12-29.
  28. ^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.

External links

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