802.11 is the set of standards that define communication for wireless LANs or
WLANs. The technology used in 802.11 is branded to consumers as Wi-Fi.
to the name , IEEE 802.11 is overseen by the IEEE, specifically the IEEE
LAN/MAN Standards Committee (IEEE 802). The current version now in use is of 802.11-2007. Actually, IEEE 802.11 is the
set of technical steps for implementing Wi-Fi. Selling products under this
trademark is checked by an industry trade association named as Wi-Fi Alliance.
802.11 standards have its roots from a year 1985 decision by the U.S. Federal
Commission for Communication that opened up the ISM band which has no license
use. It was formally released in 1997. That original standard was called IEEE
“802.11 standards” or the
“802.11 family of standards” are commonly used. However to be more precise ,now
this time only one standard existing is (IEEE 802.11-2007) but many changes commonly
known as amendments include 802.11a ,802.11b, 802.11g, and 802.11n.
WRT54GS Wi-Fi router from 2005 works on the 2.4 GHz “G” standard,
is able to transmit 54 megabits per second.
The Netgear dual-band router from 2013
uses the AC standard, is able to transmit 1900 megabits per second.
The 802.11 family consists
of a series of half-duplex over-the-air modulation techniques that use the same basic
protocol. The first wireless networking standard in the family was 802.11-1997 ,
but on market 802.11b was the first time widely accepted, supported by 802.11a,
802.11g, 802.11n, and 802.11ac. Other standards (c–f, h, j) are service changes
that are used to extend the idea of the existing standard.
802.11b and 802.11g both
use the 2.4 GHz ISM band ,now
it is operating in the United States under Part 15 of the U.S. Federal
Communications Commission Rules and Regulations. By using this choice of frequency band, 802.11b and g equipment
and this suffering occasionally interference of microwave ovens, cordless telephones and Bluetooth devices. 802.11b and 802.11g able to
control their interference and interference by using direct-sequence
and OFDM signaling methods. 802.11a uses the 5 GHz
For greater part of the world, offers at least 23 not able to interact with
channels instead of the 2.4 GHz ISM frequency band offering only three not
able to interact channels, where other adjacent channels interact —see list of wireless local area network channels. The frequencies with worst or better performance are higher or lower may be realized, depending on
the environment. 802.11n can use either the 2.4 GHz or the 5 GHz
band; GHz band is only used by 802.11ac5 .
Standards 802.11a, 802.11b/g/n:
802.11a is the first Wi-Fi wireless network communication standards which is created in the IEEE 802.11 standards family.
History of 802.11a:
The specification of 802.11a was ratified in 1999. At
that time, the only other Wi-Fi technology was being able to ready for the
market were 802.11b. (The original 802.11 did not gain widespread
deployment due to its very slow speed.)
802.11a and these other standards were incompatible, meaning that 802.11a
devices cannot interact with the other
forms and vice versa.
A maximum bandwidth of 54 Mbps is supported by an 802.11a wireless network ,
significantly better than the 11 Mbps of
802.11b and on par with what 802.11g would start to offer a few years
later. The 802.11a is an attractive technology due to its specifications, but
its performance is obtained by using relatively higher cost hardware.
and Wireless Signaling:
In the 1980s U.S.
government opened three specific
wireless frequency bands only for public use – 900 MHz (0.9 GHz), 2.4 GHz, and 5.8 GHz . 900 MHz proved
too low of frequency to be useful for data networking, although cordless phones used it.
802.11a transmits wireless spread spectrum radio signals in the 5.8 GHz
frequency range. This band was running in the U.S. and for a long time many
countries, meaning that 802.11a networks did not have to contend with signal
interference from other forms of transmitting devices. 802.11b networks
use frequencies in the often unregulated 2.4 GHz range and were much more
susceptible to radio interference from other devices.
802.11b was the first Wi-Fi wireless network communication
technology to achieve mass adoption with consumers. It is one of many Institute of Electrical and Electronics Engineers standards in the 802.11 family. 802.11b products were made
obsolete and phased out by the newer 802.11g and 802.11n Wi-Fi standards.
History of 802.11b
In the middle of
1980s, radio frequency is used
space around 2.4 GHz was controlled by government agencies in the
The U.S. Federal Communications Communication
initiated the change to remove
regulation from this band, previously limited to so-called ISM equipment. Their
basic aim was to encourage the development of commercial applications.
Building commercial wireless systems on a
large scale requires some level of technical standardization among custmoers.
That’s where the IEEE stepped in and assigned its 802.11 working group to
design a solution, which eventually became known as Wi-Fi. The first
802.11 Wi-Fi standard, published in 1997, had too many technical limitations to
be widely useful, but it paved the way for the development of a second
generation standard called 802.11b.
802.11b (nowadays called “B” for
short) helped launch the first wave of wireless home networking. With its
introduction in 1999, manufacturers of broadband routers like Linksys began selling Wi-Fi
routers alongside the wired Ethernet models they had been producing before.
Though these older products could be
difficult to set up and manage, the convenience and potential demonstrated
by 802.11b turned Wi-Fi into a huge commercial success.
802.11b connections support a theoretical
maximum data rate of 11 Mbps. Although comparable to traditional Ethernet (10 Mbps), B performs significantly
slower than all newer Wi-Fi and Ethernet technologies.
802.11b and Wireless
Transmitting in the unregulated 2.4 GHz
frequency range, 802.11b transmitters can encounter radio interference from
other wireless household products like cordless telephones, microwave ovens,
garage door openers, and baby monitors.
802.11 and Backward
Even the networks that are newest Wi-Fi
networks still support 802.11b. Due to this reason each newer generation of the main Wi-Fi
protocol standards has maintained backward compatibility with all old
generations: For example,
and access points support both G and B clients – called 802.11b/g networks
802.11n routers and access points that support N, G and
B clients – 802.11b/g/nnetworks
This backward compatibility is very good
feature has proven critical to the success of Wi-Fi, as consumers and
businesses can able to add newer equipment to their networks and gradually
phase out old devices with minimal disruption.
802.11g is an IEEE standard Wi-Fi wireless networking technology. Like other versions
of Wi-Fi, 802.11g supports wireless
local area network communications
among computers, broadband routers, and many other consumer devices.
G was ratified in June of 2003, and it is replaced the older 802.11b standard, later eventually replaced
by 802.11n and newer standards.
How Fast Is 802.11g:
802.11g Wi-Fi has ability to support a
maximum network bandwidth of 54 Mbps, which is higher than the 11 Mbps rating of B and less than the 150 Mbps or greater speeds of
many other kinds of networking, G is not able to achieve the maximum rating in
practice; 802.11g connections hit an
application data transfer rate limit between 24 Mbps and 31 Mbps.
incorporated is a radio communication
technique known as Orthogonal Frequency Division Multiplex that
was introduced to Wi-Fi with 802.11a . OFDM technology enabled G and A to
get greater network performance than B.
On the other hand, 802.11g chosen the same
2.4 GHz range of communication frequencies introduced to Wi-Fi with 802.11b.Using this
frequency gave Wi-Fi devices greater
signal range than what A can offer. 14 possible channels that 802.11g can work
on, though some are illegal in some countries. The frequencies from channel
1-14 range between 2.412 GHz to 2.484 GHz.G was specially designed for cross
What is meanings of that devices can coordinate wireless networks
even when the wireless access point runs a different Wi-Fi version.The
newest 802.11ac Wi-Fi equipment today can support
connections from G clients.
802.11g for Home Networking
There are many number of brands and models of
computer laptops and other Wi-Fi devices were made with Wi-Fi radios supporting
G. As it combined some of the best elements of A and B, 802.11g became the
predominant Wi-Fi standard at a time when the adoption of home networking
exploded worldwide.Many home networks today still operate using 802.11g routers. At 54 Mbps, these routers can keep up with
most high-speed home internet connections including basic video streaming and
online gaming usages.
They can be found inexpensively through both
retail and secondhand sales outlets. However, G networks can reach performance
limits quickly when multiple devices are connected and simultaneously active,
but this is true for any network that’s consumed by too many devices.In addition to G routers designed
for fixed installation in homes, 802.11g travel routers also gained substantial popularity with
business professionals and families who needed to share a single wired Ethernet connection among their wireless
devices.G (and some N) travel routers can still be found in retail outlets but
have become increasingly uncommon as hotel and other public internet services
shift from Ethernet to wireless hotspots.
802.11n is a standard (IEEE) for Wi-Fi wireless local network communications, contract in 2009.802.11n is
designed to exchange the 802.11a, 802.11b and 802.11g Wi-Fi technologies.
802.11n uses multiple wireless
antennas in tandem for transmitting and receiving data. The term MIMO refers to the ability of
802.11n and like other technologies to coordinate multiple simultaneous radio
signals. MIMO is used to increase the
range and throughput of a wireless network. An other technique employed by
802.11n that involves increasing the channel bandwidth. Such networks 802.11a/b/g, and each .11n
device that uses a preset Wi-Fi channel on which is used for transmitting. Such
channel will use a larger frequency range , also increasing data throughput.
802.11n connections that support
maximum theory based network bandwidth upto300 Mbps which
primarily depends on the number of wireless radios incorporated into