IEEE 802.11b-1999

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IEEE 802.11b-1999 or 802.11b is an amendment to the IEEE 802.11 wireless networking specification that extends throughput up to 11 Mbit/s using the same 2.4 GHz band. A related amendment was incorporated into the IEEE 802.11-2007 standard.

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

Description[edit]

802.11b has a maximum raw data rate of 11 Mbit/s and uses the same CSMA/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 using TCP and 7.1 Mbit/s using UDP.

802.11b products appeared on the market in mid-1999, since 802.11b is a direct extension of the DSSS (Direct-sequence spread spectrum) modulation technique defined in the original standard. The Apple iBook was the first mainstream computer sold with optional 802.11b networking. Technically, the 802.11b standard uses complementary code keying (CCK) as its modulation technique, which uses a specific set of length 8 complementary codes that was originally designed for OFDM [1] but was also suitable for use in 802.11b because of its low autocorrelation properties.[2] 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 the Wi-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.

Range[edit]

802.11b is used in a point-to-multipoint configuration, wherein an access point communicates via an omnidirectional 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 on effective radiated power.[3]

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[edit]

802.11b/g channels in 2.4 GHz band
channel to frequency map [4]
Channel  Center frequency  Frequency delta Channel width Overlaps channels
1 2.412 GHz 5 MHz 2.401–2.423 GHz 2-5
2 2.417 GHz 5 MHz 2.406–2.428 GHz 1,3-6
3 2.422 GHz 5 MHz 2.411–2.433 GHz 1–2,4-7
4 2.427 GHz 5 MHz 2.416–2.438 GHz 1–3,5-8
5 2.432 GHz 5 MHz 2.421–2.443 GHz 1–4,6-9
6 2.437 GHz 5 MHz 2.426–2.448 GHz 2–5,7-10
7 2.442 GHz 5 MHz 2.431–2.453 GHz 3–6,8-11
8 2.447 GHz 5 MHz 2.436–2.458 GHz 4–7,9-12
9 2.452 GHz 5 MHz 2.441–2.463 GHz 5–8,10-13
10 2.457 GHz 5 MHz 2.446–2.468 GHz 6–9,11-13
11 2.462 GHz 5 MHz 2.451–2.473 GHz 7-10,12-13
12 2.467 GHz 5 MHz 2.456–2.478 GHz 8-11,13-14
13 2.472 GHz 5 MHz 2.461–2.483 GHz 9-12, 14
14 2.484 GHz 12 MHz 2.473–2.495 GHz 12-13
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 the List of WLAN channels.

See also[edit]

Frequency
range, or type
PHY Protocol Release date[5] Frequency Bandwidth Stream data rate[6] Allowable
MIMO streams
Modulation Approximate range[citation needed]
Indoor Outdoor
(GHz) (MHz) (Mbit/s)
1–6 GHz DSSS/FHSS[7] 802.11-1997 Jun 1997 2.4 22 1, 2 N/A DSSS, FHSS 20 m (66 ft) 100 m (330 ft)
HR-DSSS[7] 802.11b Sep 1999 2.4 22 1, 2, 5.5, 11 N/A DSSS 35 m (115 ft) 140 m (460 ft)
OFDM 802.11a Sep 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)
N/A OFDM 35 m (115 ft) 120 m (390 ft)
802.11j Nov 2004 4.9/5.0[D][8][failed verification] ? ?
802.11p Jul 2010 5.9 ? 1,000 m (3,300 ft)[9]
802.11y Nov 2008 3.7[A] ? 5,000 m (16,000 ft)[A]
ERP-OFDM 802.11g Jun 2003 2.4 38 m (125 ft) 140 m (460 ft)
HT-OFDM[10] 802.11n (Wi-Fi 4) Oct 2009 2.4/5 20 Up to 288.8[B] 4 MIMO-OFDM 70 m (230 ft) 250 m (820 ft)[11][failed verification]
40 Up to 600[B]
VHT-OFDM[10] 802.11ac (Wi-Fi 5) Dec 2013 5 20 Up to 346.8[B] 8 MIMO-OFDM 35 m (115 ft)[12] ?
40 Up to 800[B]
80 Up to 1733.2[B]
160 Up to 3466.8[B]
HE-OFDMA 802.11ax (Wi-Fi 6) Feb 2021 2.4/5/6 20 Up to 1147[F] 8 MIMO-OFDM 30 m (98 ft) 120 m (390 ft) [G]
40 Up to 2294[F]
80 Up to 4804[F]
80+80 Up to 9608[F]
mmWave DMG[13] 802.11ad Dec 2012 60 2,160 Up to 6,757[14]
(6.7 Gbit/s)
N/A OFDM, single carrier, low-power single carrier 3.3 m (11 ft)[15] ?
802.11aj Apr 2018 45/60[C] 540/1,080[16] Up to 15,000[17]
(15 Gbit/s)
4[18] OFDM, single carrier[18] ? ?
EDMG[19] 802.11ay Est. March 2021 60 8000 Up to 20,000 (20 Gbit/s)[20] 4 OFDM, single carrier 10 m (33 ft) 100 m (328 ft)
Sub-1 GHz IoT TVHT[21] 802.11af Feb 2014 0.054–0.79 6–8 Up to 568.9[22] 4 MIMO-OFDM ? ?
S1G[21] 802.11ah Dec 2016 0.7/0.8/0.9 1–16 Up to 8.67 (@2 MHz)[23] 4 ? ?
2.4 GHz, 5 GHz WUR 802.11ba[E] Est. March 2021 2.4/5 4.06 0.0625, 0.25 (62.5 kbit/s, 250 kbit/s) N/A OOK (Multi-carrier OOK) ? ?
Light (Li-Fi) IR 802.11-1997 Jun 1997 ? ? 1, 2 N/A PPM ? ?
? 802.11bb Est. Jul 2022 60000-790000 ? ? N/A ? ? ?
802.11 Standard rollups
  802.11-2007 Mar 2007 2.4, 5 Up to 54 DSSS, OFDM
802.11-2012 Mar 2012 2.4, 5 Up to 150[B] DSSS, OFDM
802.11-2016 Dec 2016 2.4, 5, 60 Up to 866.7 or 6,757[B] DSSS, OFDM
802.11-2020 Dec 2020 2.4, 5, 60 Up to 866.7 or 6,757[B] DSSS, OFDM
  • A1 A2 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.
  • B1 B2 B3 B4 B5 B6 Based on short guard interval; standard guard interval is ~10% slower. Rates vary widely based on distance, obstructions, and interference.
  • C1 For Chinese regulation.
  • D1 For Japanese regulation.
  • E1 Wake-up Radio (WUR) Operation.
  • F1 F2 F3 F4 For single-user cases only, based on default guard interval which is 0.8 micro seconds. 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.
  • G1 The default guard interval is 0.8 micro seconds. However, 802.11ax extended the maximum available guard interval to 3.2 micro seconds, in order to support Outdoor communications, where the maximum possible propagation delay is larger compared to Indoor environments.

References[edit]

  1. ^ Van Nee, Richard (November 1996). "OFDM codes for peak-to-average power reduction and error correction". IEEE Globecom. London.
  2. ^ Webster, Mark; Andren, Carl; Boer, Jan; Van Nee, Richard (July 1998). "Harris/Lucent TGb Compromise CCK 11Mbps Proposal". IEEE 802.11-98/246a. London.
  3. ^ "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. Retrieved 2013-06-10.
  4. ^ http://download.wcvirtual.com/reference/802%20Channel%20Freq%20Mappings.pdf[permanent dead link]
  5. ^ "Official IEEE 802.11 working group project timelines". January 26, 2017. Retrieved 2017-02-12.
  6. ^ "Wi-Fi CERTIFIED n: Longer-Range, Faster-Throughput, Multimedia-Grade Wi-Fi® Networks" (PDF). Wi-Fi Alliance. September 2009.[dead link]
  7. ^ a b Banerji, Sourangsu; Chowdhury, Rahul Singha. "On IEEE 802.11: Wireless LAN Technology". arXiv:1307.2661.
  8. ^ "The complete family of wireless LAN standards: 802.11 a, b, g, j, n" (PDF).
  9. ^ Abdelgader, Abdeldime M.S.; Wu, Lenan (2014). The Physical Layer of the IEEE 802.11p WAVE Communication Standard: The Specifications and Challenges (PDF). World Congress on Engineering and Computer Science.
  10. ^ a b Wi-Fi Capacity Analysis for 802.11ac and 802.11n: Theory & Practice
  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. ^ "IEEE Standard for Information Technology--Telecommunications and information exchange between systems Local and metropolitan area networks--Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 3: Enhancements for Very High Throughput to Support Chinese Millimeter Wave Frequency Bands (60 GHz and 45 GHz)". IEEE Std 802.11aj-2018. April 2018. 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. ^ a b 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. 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. ^ Sun, Rob; Xin, Yan; Aboul-Maged, Osama; Calcev, George; Wang, Lei; Au, Edward; Cariou, Laurent; Cordeiro, Carlos; Abu-Surra, Shadi; Chang, Sanghyun; Taori, Rakesh; Kim, TaeYoung; Oh, Jongho; Cho, JanGyu; Motozuka, Hiroyuki; Wee, Gaius. "P802.11 Wireless LANs". IEEE. pp. 2, 3. Archived from the original on 2017-12-06. Retrieved December 6, 2017.
  21. ^ a b "802.11 Alternate PHYs A whitepaper by Ayman Mukaddam" (PDF).
  22. ^ Lee, Wookbong; Kwak, Jin-Sam; Kafle, Padam; Tingleff, Jens; Yucek, Tevfik; Porat, Ron; Erceg, Vinko; Lan, Zhou; Harada, Hiroshi (2012-07-10). "TGaf PHY proposal". IEEE P802.11. Retrieved 2013-12-29.
  23. ^ 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.