802.11 WLAN STANDARDS
IEEE 802.11 is the generic
name of a family of standards for wireless networking related to Wi-Fi.
These wireless networks are
becoming more popular nowadays. It acts as an alternative to the wired network,
but soon it may replace the wired network completely. The protocol is based on
multiple access where a node competes with other nodes to get access to the
communication medium and to transmit the data. This WLAN standard was passed by
Institute of Electrical and Electronics Engineers (IEEE) in June 1997.
The numbering scheme for
802.11 comes from the IEEE, who uses “802” as the name of a committee
for networking standards while “11” means the wireless local area
networks (WLANs) working group inside their 802 committee.
There are different
standards in this technology:
1: 802.11(No Suffix):
It was the original standard
in this family released in 1997. 802.11 established wireless local network
communication as a mainstream alternative to Ethernet. It used unregulated radio signaling frequency (2.4
GHz). On the other hand, it had some serious limitations that prevented
it from appearing in commercial products like data rate was just 1-2 Mbps. It
became obsolete with the evolution of 802.11a & 802.11b.
This standard was ratified in July 1999. It supports bandwidth up to 11
can be compared to traditional Ethernet. It also
uses the same frequency used by original 802.11 standard i.e. 2.4GHz.
Vendors often prefer using these frequencies to lower their production costs.
This standard was also
released at the time when 802.11b released. Due to its higher cost, 802.11a is usually found on business
networks whereas 802.11b is for home market. It supports bandwidth up to 54
Mbps and signals in a regulated frequency spectrum around 5 GHz.
802.11g attempts to combine the best of both 802.11a and 802.11b.
802.11g supports bandwidth up to 54 Mbps, and it uses the 2.4 GHz frequency for
greater range. This frequency can be interference from microwave ovens,
cordless phones, and other appliances using the same 2.4 GHz range. It was
ratified in June 2003.
This amendment that improved the previous
802.11 standards by adding Multiple Input Multiple Output antennas
(MIMO). 802.11n operates on both the 2.4 GHz and the 5 GHz bands. It
operates at a maximum net data rate from 54 Mbit/s to 600 Mbps.
This is the newest generation of Wi-Fi signaling that is used
nowadays. It utilizes dual-band wireless technology,
supporting simultaneous connections on both the 2.4 GHz and 5 GHz. It offers
bandwidth rated up to 1300 Mbps on the 5 GHz band plus up to 450 Mbps on 2.4
This amendment defines a new physical layer for 802.11 networks to operate in the
60 GHz spectrum. This frequency band has significantly different
propagation characteristics than the 2.4 GHz and 5 GHz bands.
Products implementing this standard are being brought to market.
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