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802.11 Wireless Standards - CompTIA Network+ N10-006 - 5.3
802.11 Wireless Standards - CompTIA Network+ N10-006 - 5.3
Published: 2015/05/14
Channel: Professor Messer
CSE 574-14-06A: Wireless LANs Part II: IEEE 802.11a/b/g/n/ac (Part 1 of 2)
CSE 574-14-06A: Wireless LANs Part II: IEEE 802.11a/b/g/n/ac (Part 1 of 2)
Published: 2014/06/05
Channel: Raj Jain
wireless lans 802.11a,b,g,n
wireless lans 802.11a,b,g,n
Published: 2017/07/28
Channel: tech dude
[Hindi/Urdu] WiFi Explained in Detail | Wifi 802.11 a, b, g, n, ac
[Hindi/Urdu] WiFi Explained in Detail | Wifi 802.11 a, b, g, n, ac
Published: 2016/01/04
Channel: Technical Guruji
IEEE 802.11 Wireless LANs Revisited- Part 9: 802.11a/b/g/n/ac
IEEE 802.11 Wireless LANs Revisited- Part 9: 802.11a/b/g/n/ac
Published: 2017/09/22
Channel: Scholartica Channel
Why you should move to 5Ghz wireless 802-11a
Why you should move to 5Ghz wireless 802-11a
Published: 2011/01/15
Channel: Jason Aarons
CSE 574-14-06B: Wireless LANs Part II: IEEE 802.11a/b/g/n/ac (Part 2 of 2)
CSE 574-14-06B: Wireless LANs Part II: IEEE 802.11a/b/g/n/ac (Part 2 of 2)
Published: 2014/06/05
Channel: Raj Jain
CSE574-16-06A: Wireless LANs Part II: 802.11a/b/g/n/ac (Part 1 of 3)
CSE574-16-06A: Wireless LANs Part II: 802.11a/b/g/n/ac (Part 1 of 3)
Published: 2016/10/04
Channel: Raj Jain
WiFi Interfaces: Comparison of 802.11a/b/g/n
WiFi Interfaces: Comparison of 802.11a/b/g/n
Published: 2013/09/19
Channel: Amod Agrawal
IEEE 802.11 Wireless LANs Revisited- Part 11: 802.11 a & b
IEEE 802.11 Wireless LANs Revisited- Part 11: 802.11 a & b
Published: 2017/10/01
Channel: Scholartica Channel
CSE574-16-06C: Wireless LANs Part II: 802.11a/b/g/n/ac (Part 3 of 3)
CSE574-16-06C: Wireless LANs Part II: 802.11a/b/g/n/ac (Part 3 of 3)
Published: 2016/10/04
Channel: Raj Jain
IEEE 802.11n-2009
IEEE 802.11n-2009
Published: 2014/08/13
Channel: Audiopedia
5GHz WiFi Long Range Parabolic Grids - 802.11a/ac Long Range Antennas
5GHz WiFi Long Range Parabolic Grids - 802.11a/ac Long Range Antennas
Published: 2016/11/07
Channel: SimpleWiFi
Demo: GNU Radio IEEE 802.11a/g/p OFDM Receiver
Demo: GNU Radio IEEE 802.11a/g/p OFDM Receiver
Published: 2013/07/16
Channel: Bastian Bloessl
ZyXEL AG-225H 802.11 a/b/g/n WiFi Finder
ZyXEL AG-225H 802.11 a/b/g/n WiFi Finder
Published: 2009/04/29
Channel: bluedonuts06
IEEE 802.11a Standard with 5GHz frequency at data rate of 54Mbps in NS2
IEEE 802.11a Standard with 5GHz frequency at data rate of 54Mbps in NS2
Published: 2017/04/25
Channel: Shan Ahmed
B200: WiFi 802.11a Decoder
B200: WiFi 802.11a Decoder
Published: 2014/12/01
Channel: balint256
GNURadio-based IEEE 802.11 a/g/p OFDM Receiver Demo
GNURadio-based IEEE 802.11 a/g/p OFDM Receiver Demo
Published: 2013/12/15
Channel: Kexiong Zeng
[HINDI] How does WiFi Work ? | Learn about 802.11/a/b/g/n, WEP, WPA, WPA - 2 | Logical Broadcast
[HINDI] How does WiFi Work ? | Learn about 802.11/a/b/g/n, WEP, WPA, WPA - 2 | Logical Broadcast
Published: 2017/05/10
Channel: Logical Broadcast
Using CombiTest and the Anritsu MT8860C to validate an 802.11a/b/g/n module
Using CombiTest and the Anritsu MT8860C to validate an 802.11a/b/g/n module
Published: 2011/08/10
Channel: AnritsuCompany
CSE574-16-06B: Wireless LANs Part II: 802.11a/b/g/n/ac (Part 2 of 3)
CSE574-16-06B: Wireless LANs Part II: 802.11a/b/g/n/ac (Part 2 of 3)
Published: 2016/10/04
Channel: Raj Jain
GNURadio-based IEEE 802.11 a/g/p OFDM Transmitter Demo
GNURadio-based IEEE 802.11 a/g/p OFDM Transmitter Demo
Published: 2013/12/15
Channel: Kexiong Zeng
WIRELESS STANDARD. 802.11a,b,g,n Frequency, Data rate, Channel - CCNA
WIRELESS STANDARD. 802.11a,b,g,n Frequency, Data rate, Channel - CCNA
Published: 2011/03/30
Channel: Just Sharing, Whatever
Modeling and Simulation of OFDM (IEEE 802.11a) in CAPSIM
Modeling and Simulation of OFDM (IEEE 802.11a) in CAPSIM
Published: 2018/02/14
Channel: Silicon DSP Corporation
WLAN 기술에 대한 모든 것 (IEEE 802.11a to zz  The Expanding World of Wi-Fi)
WLAN 기술에 대한 모든 것 (IEEE 802.11a to zz The Expanding World of Wi-Fi)
Published: 2015/05/15
Channel: KEYSIGHT WEBCASTS
Apple Express Wi-Fi Router PAIR - 802.11 a/b/g/n - Dual Band
Apple Express Wi-Fi Router PAIR - 802.11 a/b/g/n - Dual Band
Published: 2015/12/14
Channel: Chris W Gooley
GNURadio-based IEEE 802.11 a/g/p OFDM Receiver Graphical Outputs Demo
GNURadio-based IEEE 802.11 a/g/p OFDM Receiver Graphical Outputs Demo
Published: 2013/12/15
Channel: Kexiong Zeng
EPCOS OHG, Wireless LAN (802.11 a,b,g) - Module
EPCOS OHG, Wireless LAN (802.11 a,b,g) - Module
Published: 2009/09/09
Channel: Steirische Wirtschaftsförderung SFG
IEEE 802.11 Wireless LANs Revisited- Part 10: PDU
IEEE 802.11 Wireless LANs Revisited- Part 10: PDU
Published: 2017/09/27
Channel: Scholartica Channel
Simulation of Viterbi Decoder IEEE 802.11a using Simulink Matlab
Simulation of Viterbi Decoder IEEE 802.11a using Simulink Matlab
Published: 2012/06/03
Channel: Tuan Anh Nguyen
WIFI || what is wifi || how dose it work || wifi 802.11 a,b,g,n,ac || Technician Biswa
WIFI || what is wifi || how dose it work || wifi 802.11 a,b,g,n,ac || Technician Biswa
Published: 2017/10/07
Channel: Technician Biswa
AirMagnet to introuce Survey for 802.11 a/b/g/n networks
AirMagnet to introuce Survey for 802.11 a/b/g/n networks
Published: 2008/05/06
Channel: avingusa
SISO-OFDM transmission system (IEEE 802.11a standard)
SISO-OFDM transmission system (IEEE 802.11a standard)
Published: 2014/11/23
Channel: Taha Alwajeeh
Cisco Aironet 1252ag 802.11a/g/n Wireless Access Point, New
Cisco Aironet 1252ag 802.11a/g/n Wireless Access Point, New
Published: 2016/07/12
Channel: Ashley Derrick
802.11a/n Wireless Access Point | VX-AP320NA | Versatek
802.11a/n Wireless Access Point | VX-AP320NA | Versatek
Published: 2016/01/08
Channel: Versa Technology, Inc.
802.11 Communications
802.11 Communications
Published: 2013/11/13
Channel: wifi renault
New This Week at Mouser Electronics -- B&B Electronics Airborne Embedded 802.11a/b/g/n
New This Week at Mouser Electronics -- B&B Electronics Airborne Embedded 802.11a/b/g/n
Published: 2014/04/16
Channel: Mouser Electronics
Wireless Hacking 09 Wireless Modes   ABGN
Wireless Hacking 09 Wireless Modes ABGN
Published: 2015/07/30
Channel: Hacker Pull
ECE2305 Lecture 16
ECE2305 Lecture 16
Published: 2015/11/24
Channel: WPI
How Does work Wi-Fi | WiFi Explained in Detail | Wifi 802.11 a, b, g, n, ac In Hindi Part 2
How Does work Wi-Fi | WiFi Explained in Detail | Wifi 802.11 a, b, g, n, ac In Hindi Part 2
Published: 2018/02/20
Channel: Munawar IT Corner
DealExtreme 2000mW High Power 802.11a/b/g USB Wireless Network Dongle with 10dBi Antenna
DealExtreme 2000mW High Power 802.11a/b/g USB Wireless Network Dongle with 10dBi Antenna
Published: 2011/10/05
Channel: noodl34u
Wireless N USB Adapter Dongle 802.11a/b/g/n WiFi Antenna FOR ONLY $10 DOLLARS REVIEW AND UNBOXING
Wireless N USB Adapter Dongle 802.11a/b/g/n WiFi Antenna FOR ONLY $10 DOLLARS REVIEW AND UNBOXING
Published: 2017/02/10
Channel: Gary3dfx TECH
AirLive X.USB - 802.11 a/b/g/n Dual Band USB Adapter to Connect Your PC to Any Network
AirLive X.USB - 802.11 a/b/g/n Dual Band USB Adapter to Connect Your PC to Any Network
Published: 2011/01/23
Channel: AirLiveMedia
4 2 802 11a   CCNA Wireless 200 355
4 2 802 11a CCNA Wireless 200 355
Published: 2017/09/27
Channel: Cisco Wireless Videos
AirMax5X
AirMax5X
Published: 2014/09/17
Channel: Wang Sam
Demo of an 802.11a/g sniffer implemented in Ziria
Demo of an 802.11a/g sniffer implemented in Ziria
Published: 2016/06/22
Channel: Microsoft Research
Wi-Fi | Курс "Компьютерные сети"
Wi-Fi | Курс "Компьютерные сети"
Published: 2016/10/30
Channel: Andrey Sozykin
Wireless Interfaces
Wireless Interfaces
Published: 2014/10/15
Channel: Siddharth Arya
4.9GHz to 5.85GHz 802.11a/n Front End Module
4.9GHz to 5.85GHz 802.11a/n Front End Module
Published: 2012/07/20
Channel: RFMDMedia
Netgear Nighthawk X4s D7800100pes Ac2600 Wlan Vdsl2/adsl2+ Modemrouter
Netgear Nighthawk X4s D7800100pes Ac2600 Wlan Vdsl2/adsl2+ Modemrouter
Published: 2016/07/16
Channel: Antwan Theriault
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WIKIPEDIA ARTICLE

From Wikipedia, the free encyclopedia
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IEEE 802.11a-1999 or 802.11a was an amendment to the IEEE 802.11 wireless local network specifications that defined requirements for an orthogonal frequency division multiplexing (OFDM) communication system. It was originally designed to support wireless communication in the unlicensed national information infrastructure (U-NII) bands (in the 5–6 GHz frequency range) as regulated in the United States by the Code of Federal Regulations, Title 47, Section 15.407.

Originally described as clause 17 of the 1999 specification, it is now defined in clause 18 of the 2012 specification and provides protocols that allow transmission and reception of data at rates of 1.5 to 54Mbit/s. It has seen widespread worldwide implementation, particularly within the corporate workspace. While the original amendment is no longer valid, the term "802.11a" is still used by wireless access point (cards and routers) manufacturers to describe interoperability of their systems at 5.8 GHz, 54 Mbit/s (54 x 106 bits per second).

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 and 802.11ac versions to provide wireless connectivity in the home, office and some commercial establishments.

Description[edit]

The 802.11a amendment to the original standard was ratified in 1999. The 802.11a standard uses the same core protocol as the original standard, operates in 5 GHz band, and uses a 52-subcarrier orthogonal frequency-division multiplexing (OFDM) with a maximum raw data rate of 54 Mbit/s, which yields realistic net achievable throughput in the mid-20 Mbit/s. The data rate is reduced to 48, 36, 24, 18, 12, 9 then 6 Mbit/s if required. 802.11a originally had 12/13 non-overlapping channels, 12 that can be used indoor and 4/5 of the 12 that can be used in outdoor point to point configurations. Recently many countries of the world are allowing operation in the 5.47 to 5.725 GHz Band as a secondary user using a sharing method derived in 802.11h. This will add another 12/13 Channels to the overall 5 GHz band enabling significant overall wireless network capacity enabling the possibility of 24+ channels in some countries. 802.11a is not interoperable with 802.11b as they operate on separate bands, except if using equipment that has a dual band capability. Most enterprise class Access Points have dual band capability.

Using the 5 GHz band gives 802.11a a significant advantage, since the 2.4 GHz band is heavily used to the point of being crowded. Degradation caused by such conflicts can cause frequent dropped connections and degradation of service. However, this high carrier frequency also brings a slight disadvantage: The effective overall range of 802.11a is slightly less than that of 802.11b/g; 802.11a signals cannot penetrate as far as those for 802.11b because they are absorbed more readily by walls and other solid objects in their path and because the path loss in signal strength is proportional to the square of the signal frequency. On the other hand, OFDM has fundamental propagation advantages when in a high multipath environment, such as an indoor office, and the higher frequencies enable the building of smaller antennas with higher RF system gain which counteract the disadvantage of a higher band of operation. The increased number of usable channels (4 to 8 times as many in FCC countries) and the near absence of other interfering systems (microwave ovens, cordless phones, baby monitors) give 802.11a significant aggregate bandwidth and reliability advantages over 802.11b/g.

Regulatory issues[edit]

Different countries have different regulatory support, although a 2003 World Radiotelecommunications Conference improved worldwide standards coordination. 802.11a is now approved by regulations in the United States and Japan, but in other areas, such as the European Union, it had to wait longer for approval. European regulators were considering the use of the European HIPERLAN standard, but in mid-2002 cleared 802.11a for use in Europe. In the U.S., a mid-2003 FCC decision may open more spectrum to 802.11a channels.[needs update]

Timing and compatibility of products[edit]

802.11a products started shipping late, lagging 802.11b products due to 5 GHz components being more difficult to manufacture. First generation product performance was poor and plagued with problems. When second generation products started shipping, 802.11a was not widely adopted in the consumer space primarily because the less-expensive 802.11b was already widely adopted. However, 802.11a later saw significant penetration into enterprise network environments, despite the initial cost disadvantages, particularly for businesses which required increased capacity and reliability over 802.11b/g-only networks.

With the arrival of less expensive early 802.11g products on the market, which were backwards-compatible with 802.11b, the bandwidth advantage of the 5 GHz 802.11a was eliminated. Manufacturers of 802.11a equipment responded to the lack of market success by significantly improving the implementations (current-generation 802.11a technology has range characteristics nearly identical to those of 802.11b), and by making technology that can use more than one band a standard.

Dual-band, or dual-mode Access Points and Network Interface Cards (NICs) that can automatically handle a and b/g, are now common in all the markets, and very close in price to b/g- only devices.

Technical description[edit]

Of the 52 OFDM subcarriers, 48 are for data and 4 are pilot subcarriers with a carrier separation of 0.3125 MHz (20 MHz/64). Each of these subcarriers can be a BPSK, QPSK, 16-QAM or 64-QAM. The total bandwidth is 20 MHz with an occupied bandwidth of 16.6 MHz. Symbol duration is 4 microseconds, which includes a guard interval of 0.8 microseconds. The actual generation and decoding of orthogonal components is done in baseband using DSP which is then upconverted to 5 GHz at the transmitter. Each of the subcarriers could be represented as a complex number. The time domain signal is generated by taking an Inverse Fast Fourier transform (IFFT). Correspondingly the receiver downconverts, samples at 20 MHz and does an FFT to retrieve the original coefficients. The advantages of using OFDM include reduced multipath effects in reception and increased spectral efficiency.

RATE bits Modulation
type
Coding
rate
Data rate
(Mbit/s)(*)
1101 BPSK 1/2 6
1111 BPSK 3/4 9
0101 QPSK 1/2 12
0111 QPSK 3/4 18
1001 16-QAM 1/2 24
1011 16-QAM 3/4 36
0001 64-QAM 2/3 48
0011 64-QAM 3/4 54

(*) The data rate is for 20 MHz channel spacing.

See also[edit]

References[edit]

  1. ^ "Official IEEE 802.11 working group project timelines". January 26, 2017. Retrieved 2017-02-12. 
  2. ^ "Wi-Fi CERTIFIED n: Longer-Range, Faster-Throughput, Multimedia-Grade Wi-Fi® Networks" (registration required). Wi-Fi Alliance. September 2009. 
  3. ^ "802.11n Delivers Better Range". Wi-Fi Planet. 2007-05-31. 
  4. ^ "IEEE 802.11ac: What Does it Mean for Test?" (PDF). LitePoint. October 2013. 
  5. ^ 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. 
  6. ^ "802.11ad - WLAN at 60 GHz: A Technology Introduction" (PDF). Rohde & Schwarz GmbH. November 21, 2013. p. 14. 
  7. ^ 802.11ad Antenna Differences: Beamsteering, Gain and Range
  8. ^ 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.125. 
  9. ^ 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. 
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