Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
specifications.
The 802.11 family define a Wireless Local Area Network [WLAN]
using the Ethernet
protocol, using Carrier Sense, Multiple Access with Collision Avoidance
(CSMA/CA). The 802.11 wireless LAN standards provide a number of
channels within each frequency band, and a number of data rates. The
highest data rate is listed below. The 802.11 standard also specified
infrared [IR], but I think the IrDA standard was more widely used.
Frequency-Hopping Spread Spectrum [FHSS], or direct sequence Spread
Spectrum [DSSS] are specified. 802.11 specifies a LAN with a minimum of
two stations.
802.11b [Wi-Fi] transmit at a frequency of 2.4 GHz with
data rates up to 11 Mbps using Complementary Code Keying modulation
[CCK]. IEEE802.11b was released in 1999. Four data rates are possible; 1,
2, 5.5, and 11Mbps [bits-per-second] on up to 3 non-overlapping channels
between the frequencies of 2.4Ghz and 2.497GHz.
The 802.11b standard was rendered obsolete with the introduction of
IEEE802.11g in 2003. There are very few Wireless-B products offered any
longer due to fact that Wireless-g equipment operates at a much higher
speed and over a greater distance [at the higher speeds].
802.11a [Wi-Fi] transmit at a frequency of 5 GHz with data
rates of 54 Mbps using Orthogonal Frequency Division Multiplexing
[OFDM].
802.11g transmit at a
frequency of 2.4 GHz with data rates of 54Mbps {OFDM, DSSS]. IEEE 802.11b
and 802.11g are compatible, devices can coexist in the same
network.
802.11h transmit at a frequency of 5GHz with data rates of
100Mbps. IEEE 802.11b and 802.11g are compatible so devices can coexist
in the same network.
802.11n transmit at a
frequency of 2.4GHz or 5 GHz with data rates of 600Mbps. IEEE 802.11b and
802.11g are compatible, devices can coexist in the same network.
The 2.4GHz band is part of the ISM [Industrial, Scientific, and Medical] license-free radio bands [see below]. Both 802.11 and Bluetooth operate with in the band. Additional frequencies of the ISM band include the 900MHz band, and 5.8GHz band
Companies which manufacture Wireless ICs are listed on the RF component manufacturers page
For reference the IEEE 802.xx Family of standards is listed below:
IEEE 802.1 Higher layer LAN protocols
IEEE 802.2 Logical link control
IEEE 802.3 Ethernet, listed on its own page.
IEEE 802.4 Token bus
IEEE 802.5 Token Ring, used FDDI.
IEEE 802.6 metropolitan area networks
IEEE 802.7 broadband
IEEE 802.8 fiber optic
IEEE 802.9 isochronous LAN
IEEE 802.10 Security
IEEE 802.11 Wireless LAN [ISO/IEC 8802-11]
IEEE 802.12 demand priority
IEEE 802.13 (not used)
IEEE 802.14 Cable modems (In-active)
IEEE 802.15 Wireless PAN [Personal Area Networks]
IEEE 802.16 Broadband wireless access
IEEE 802.17 Resilient packet ring
IEEE 802.20 Mobile Broadband Wireless Access
[Industrial, Scientific, and Medical], license-free radio bands
6780 kHz ±15.0 kHz
13560 kHz ±17.0 kHz
27120 kHz ±163.0 kHz
40.68 MHz ±20.0 kHz
915 MHz ±13.0 MHz
2450 MHz ±50.0 MHz
5800 MHz ±75.0 MHz
24.125 GHz ±125.0 MHz
61.25 GHz ±250.0 MHz
122.5 GHz ±500.0 MHz
245 GHz ±1.0 GHz
Chart of US Frequency Allocations *.pdf {NTIA}
BWA: Broadband wireless access
LOS: Line-of-Sight
NLOS: Non-Line-of-Sight
WEP: Wired Equivalent Privacy
WPA: Wi-Fi Protected Access
Engineering Design Key words: IEEE802.11b, Ad hoc network, Air, Radio, Wireless Ethernet, 802.11, Wireless Local Area Networks, WEP, OFDM, AES, Wireless LANs, Wireless Personal Area Networks, Wireless PANs, WiMax, Wireless Metropolitan Area Networks, Wireless MANs, Mobile, 802.11a/b/g/h, 802.15, 802.16, Metropolitan area network, MAN, CSMA/CD, Independent Basic Service Set, Station, Mobile, Portable, Networking.
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