IEEE 802.11 (legacy mode) – or more correctly IEEE 802.11-1997 or IEEE 802.11-1999 – refer 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.
Contents
1Description
2Comparison
3Notes
4References
5Further reading
Description
It specified two raw data rates of 1 and 2 megabits per second (Mbit/s) to be transmitted via infrared (IR) signals or by either frequency hopping or direct-sequence spread spectrum (DSSS) in the 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.[1]
At least six different, somewhat-interoperable, commercial products appeared using the original specification, from companies like Alvarion (PRO.11 and BreezeAccess-II), BreezeCom, Digital / Cabletron (RoamAbout), Lucent, Netwave Technologies (AirSurfer Plus and AirSurfer Pro), Symbol Technologies (Spectrum25), and Proxim Wireless (OpenAir and Rangela2). 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 operability.
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.
Comparison
v
t
e
IEEE 802.11 network PHY standards
Frequency range, or type
PHY
Protocol
Release date[2]
Frequency
Bandwidth
Stream data rate[3]
Allowable MIMO streams
Modulation
Approximate range[citation needed]
Indoor
Outdoor
(GHz)
(MHz)
(Mbit/s)
1–6GHz
DSSS/FHSS[4]
802.11-1997
Jun 1997
2.4
22
1, 2
N/A
DSSS, FHSS
20 m (66 ft)
100 m (330 ft)
HR-DSSS[4]
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 20MHz bandwidth, divide by 2 and 4 for 10 and 5MHz)
N/A
OFDM
35 m (115 ft)
120 m (390 ft)
802.11j
Nov 2004
4.9/5.0[D][5][failed verification]
?
?
802.11p
Jul 2010
5.9
?
1,000 m (3,300 ft)[6]
802.11y
Nov 2008
3.7[A]
?
5,000 m (16,000 ft)[A]
ERP-OFDM(, etc.)
802.11g
Jun 2003
2.4
38 m (125 ft)
140 m (460 ft)
HT-OFDM[7]
802.11n
Oct 2009
2.4/5
20
Up to 288.8[B]
4
MIMO-OFDM
70 m (230 ft)
250 m (820 ft)[8][failed verification]
40
Up to 600[B]
VHT-OFDM[7]
802.11ac
Dec 2013
5
20
Up to 346.8[B]
8
MIMO-OFDM
35 m (115 ft)[9]
?
40
Up to 800[B]
80
Up to 1733.2[B]
160
Up to 3466.8[B]
HE-OFDM
802.11ax
September 2019 [10]
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[11]
802.11ad
Dec 2012
60
2,160
Up to 6,757[12] (6.7Gbit/s)
N/A
OFDM, singlecarrier, low-power singlecarrier
3.3 m (11 ft)[13]
?
802.11aj
Apr 2018
45/60[C]
540/1,080[14]
Up to 15,000[15] (15Gbit/s)
4[16]
OFDM, singlecarrier[16]
?
?
EDMG[17]
802.11ay
Est. May 2020
60
8000
Up to 20,000 (20Gbit/s)[18]
4
OFDM, singlecarrier
10m (33ft)
100m (328ft)
Sub-1GHz IoT
TVHT[19]
802.11af
Feb 2014
0.054–0.79
6–8
Up to 568.9[20]
4
MIMO-OFDM
?
?
S1G[19]
802.11ah
Dec 2016
0.7/0.8/0.9
1–16
Up to 8.67 (@2 MHz)[21]
4
?
?
2.4GHz, 5GHz
WUR
802.11ba[E]
Est. Sep 2020
2.4/5
4.06
0.0625, 0.25 (62.5kbit/s, 250kbit/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 2021
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
A1A2 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.
B1B2B3B4B5B6 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.
F1F2F3F4 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.
Notes
References
↑Maufer, Thomas (2004). A Field Guide to Wireless LANs: For Administrators and Power Users. Prentice Hall Professional. p. 144. 0131014064. ISBN 9780131014060. https://books.google.com/books?id=GB-87qyhc8sC&pg=PA142. Retrieved 2015-10-27.
↑"Official IEEE 802.11 working group project timelines". January 26, 2017. http://grouper.ieee.org/groups/802/11/Reports/802.11_Timelines.htm. Retrieved 2017-02-12.
↑"Wi-Fi CERTIFIED n: Longer-Range, Faster-Throughput, Multimedia-Grade Wi-Fi® Networks". Wi-Fi Alliance. September 2009. http://www.wi-fi.org/register.php?file=wp_Wi-Fi_CERTIFIED_n_Industry.pdf.[|permanent dead link|dead link}}]
↑"The complete family of wireless LAN standards: 802.11 a, b, g, j, n". https://cdn.rohde-schwarz.com/pws/dl_downloads/dl_common_library/dl_news_from_rs/183/n183_lan.pdf.
↑Abdelgader, Abdeldime M.S.; Wu, Lenan (2014). "The Physical Layer of the IEEE 802.11p WAVE Communication Standard: The Specifications and Challenges". World Congress on Engineering and Computer Science. http://www.iaeng.org/publication/WCECS2014/WCECS2014_pp691-698.pdf.
↑ 7.07.1Wi-Fi Capacity Analysis for 802.11ac and 802.11n: Theory & Practice
↑"IEEE 802.11ac: What Does it Mean for Test?". LitePoint. October 2013. http://litepoint.com/whitepaper/80211ac_Whitepaper.pdf.
↑"Wi-Fi 6 Routers: What You Can Buy Now (and Soon) | Tom's Guide". https://www.tomsguide.com/amp/us/best-wifi-6-routers,review-6115.html.
↑"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. https://ieeexplore.ieee.org/document/8345727.
↑"802.11ad - WLAN at 60 GHz: A Technology Introduction". Rohde & Schwarz GmbH. November 21, 2013. p. 14. https://cdn.rohde-schwarz.com/pws/dl_downloads/dl_application/application_notes/1ma220/1MA220_2e_WLAN_11ad_WP.pdf.
↑ 16.016.1Hong, Wei; He, Shiwen; Wang, Haiming; Yang, Guangqi; Huang, Yongming; Chen, Jixing; Zhou, Jianyi; Zhu, Xiaowei et al. (2018). "An Overview of China Millimeter-Wave Multiple Gigabit Wireless Local Area Network System". IEICE Transactions on CommunicationsE101.B (2): 262-276. doi:10.1587/transcom.2017ISI0004. https://www.jstage.jst.go.jp/article/transcom/E101.B/2/E101.B_2017ISI0004/_pdf.
↑"IEEE 802.11ay: 1st real standard for Broadband Wireless Access (BWA) via mmWave – Technology Blog". https://techblog.comsoc.org/2018/06/15/ieee-802-11ay-1st-real-standard-for-broadband-wireless-access-bwa-via-mmwave/.
↑Sun, Rob; Xin, Yan; Aboul-Maged, Osama; Calcev, George; Wang, Lei; Au, Edward; Cariou, Laurent; Cordeiro, Carlos et al.. "P802.11 Wireless LANs". IEEE. pp. 2,3. Archived from the original. Error: If you specify |archiveurl=, you must also specify |archivedate=. https://web.archive.org/web/20171206183820/https://mentor.ieee.org/802.11/dcn/15/11-15-1074-00-00ay-11ay-functional-requirements.docx. Retrieved December 6, 2017.
↑ 19.019.1"802.11 Alternate PHYs A whitepaper by Ayman Mukaddam". https://www.cwnp.com/uploads/802-11alternatephyswhitepaper.pdf.
↑Sun, Weiping; Choi, Munhwan; Choi, Sunghyun (July 2013). "IEEE 802.11ah: A Long Range 802.11 WLAN at Sub 1 GHz". Journal of ICT Standardization1 (1): 83–108. doi:10.13052/jicts2245-800X.115. http://riverpublishers.com/journal/journal_articles/RP_Journal_2245-800X_115.pdf.
Further reading
IEEE 802.11 Working Group (1997-11-18). IEEE Standard for Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications. doi:10.1109/IEEESTD.1997.85951. ISBN 1-55937-935-9.
IEEE 802.11 Working Group (1999-07-15). 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. doi:10.1109/IEEESTD.2003.95617. ISBN 0-7381-1857-5.
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