11Definition :IEEE802.11 is the set of standards that define communication for wireless LANs orWLANs. The technology used in 802.11 is branded to consumers as Wi-Fi.Accordingto the name , IEEE 802.11 is overseen by the IEEE, specifically the IEEELAN/MAN Standards Committee (IEEE 802). The current version now in use is of 802.
11-2007. Actually, IEEE 802.11 is theset of technical steps for implementing Wi-Fi. Selling products under thistrademark is checked by an industry trade association named as Wi-Fi Alliance.
IEEE802.11 standards have its roots from a year 1985 decision by the U.S. FederalCommission for Communication that opened up the ISM band which has no licenseuse. It was formally released in 1997.
That original standard was called IEEE802.11-1997. “802.11 standards” or the”802.11 family of standards” are commonly used. However to be more precise ,nowthis time only one standard existing is (IEEE 802.11-2007) but many changes commonlyknown as amendments include 802.11a ,802.
11b, 802.11g, and 802.11n. This LinksysWRT54GS 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 2013uses the AC standard, is able to transmit 1900 megabits per second. Brief Description:The 802.
11 family consistsof a series of half-duplex over-the-air modulation techniques that use the same basicprotocol. 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 changesthat are used to extend the idea of the existing standard.802.11b and 802.
11g bothuse the 2.4 GHz ISM band ,nowit is operating in the United States under Part 15 of the U.S.
FederalCommunications Commission Rules and Regulations. By using this choice of frequency band, 802.11b and g equipmentand this suffering occasionally interference of microwave ovens, cordless telephones,and Bluetooth devices. 802.
11b and 802.11g able tocontrol their interference and interference by using direct-sequencespread spectrum and OFDM signaling methods. 802.
11a uses the 5 GHzU-NII band,For larger part of the world, offers at least 23 not able to interact withchannels rather than the 2.4 GHz ISM frequency band offering only threenot able to interact channels, where other adjacent channels interact —see list of WLAN channels. Better or worseperformance with higher or lower frequencies (channels) may be realized,depending on the environment. 802.11n can use either the 2.4 GHz or the5 GHz band; 802.11ac uses only the 5 GHz band. WirelessStandards 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 802.11a specification was ratified in 1999. At thattime, the only other Wi-Fi technology being readied for the marketwere 802.
11b. (The original 802.11 did not gain widespreaddeployment due to its excessively slow speed.) 802.11a and these otherstandards were incompatible, meaning that 802.11a devices cannot communicatewith the other kinds and vice versa.An 802.
11a wireless network is able to support a maximum bandwidth of 54 Mbps, significantly better than the 11 Mbps of 802.11b and on parwith what 802.11gwould start to offer a few yearslater. The 802.
11a is an attractive technology due to its performance, butgetting that level of performance required using relatively higher costhardware. 802.11a and Wireless Signaling:In the 1980s U.S.government opened three specificwireless frequency bands only for public use – 900 MHz (0.9 GHz), 2.4 GHz, and 5.8 GHz .
900 MHz provedtoo 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 GHzfrequency range.
This band was running in the U.S. and for a long time manycountries, meaning that 802.11a networks did not have to contend with signalinterference from other forms of transmitting devices. 802.11b networksuse frequencies in the often unregulated 2.
4 GHz range and were much moresusceptible to radio interference from other devices.802.11b was the first Wi-Fi wireless network communicationtechnology 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 madeobsolete and phased out by the newer 802.11g and 802.11n Wi-Fi standards.
History of 802.11bIn the middle of 1980s, radio frequency is usedspace around 2.4 GHz was controlled by government agencies in theworld.The U.S. Federal Communications Communication initiated the change to removeregulation from this band, previously limited to so-called ISM equipment.
Theirbasic aim was to encourage the development of commercial applications.Building commercial wireless systems on alarge scale requires some level of technical standardization among custmoers.That’s where the IEEE stepped in and assigned its 802.11 working group todesign a solution, which eventually became known as Wi-Fi.
The first802.11 Wi-Fi standard, published in 1997, had too many technical limitations tobe widely useful, but it paved the way for the development of a secondgeneration standard called 802.11b.802.11b (nowadays called “B” forshort) helped launch the first wave of wireless home networking. With itsintroduction in 1999, manufacturers of broadband routers like Linksys began selling Wi-Firouters alongside the wired Ethernet models they had been producing before.Though these older products could be difficultto set up and manage, the convenience and potential demonstratedby 802.11b turned Wi-Fi into a huge commercial success.
802.11b Performance:802.11b connections support atheoretical maximum data rate of 11 Mbps. Although comparable to traditional Ethernet (10 Mbps), B performssignificantly slower than all newer Wi-Fi and Ethernet technologies.802.
11b and WirelessInterference:Transmitting in the unregulated 2.4 GHzfrequency range, 802.11b transmitters can encounter radio interference fromother wireless household products like cordless telephones, microwave ovens,garage door openers, and baby monitors.802.
11 and BackwardCompatibility:Even the networks that are newest Wi-Finetworks still support 802.11b. Due to this reason each newer generation of the main Wi-Fiprotocol standards has maintained backward compatibility with all oldgenerations: For example, 802.11g routers 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/nnetworksThis backward compatibility is very goodfeature has proven critical to the success of Wi-Fi, as consumers andbusinesses can able to add newer equipment to their networks and graduallyphase out old devices with minimal disruption.802.
11g is an IEEE standard Wi-Fi wireless networking technology. Like other versionsof Wi-Fi, 802.11g (sometimes referred to simply as “G”)supports wireless local area network (WLAN) communications amongcomputers, broadband routers, and many other consumer devices. G was ratified in June of 2003, and replaced the older 802.
11b (“B”) standard, latereventually replaced by 802.11n (“N”) and newer standards.How Fast Is 802.11g:802.11g Wi-Fi has ability to support amaximum network bandwidth of 54 Mbps, which is higher than the 11 Mbps rating of B and less than the 150 Mbps or greater speeds ofN.
Similarly many other kinds ofnetworking, G is not able to achieve the maximum rating in practice; 802.11gconnections hit an application datatransfer rate limit between 24 Mbps and 31 Mbps. Working: Gincorporated is a radio communicationtechnique known as Orthogonal Frequency Division Multiplex thatwas introduced to Wi-Fi with 802.11a .
OFDM technology enabled G and A toget greater network performance than B.On the other hand, 802.11g chosen the same2.4 GHz range of communication frequencies introduced to Wi-Fi with 802.11b.
Using thisfrequency gave Wi-Fi devices greatersignal range than what A can offer. 14 possible channels that 802.11g can workon, though some are illegal in some countries.
The frequencies from channel1-14 range between 2.412 GHz to 2.484 GHz.
G was specially designed for crosscompatibility.What is meanings of that devices can coordinate wireless networkseven when the wireless access point runs a different Wi-Fi version.Thenewest 802.11ac Wi-Fi equipment today can supportconnections from G clients.
802.11g for Home Networkingand Travel:Numerous brands and models of computerlaptops and other Wi-Fi devices were manufactured with Wi-Fi radios supportingG. As it combined some of the best elements of A and B, 802.11g became thepredominant Wi-Fi standard at a time when the adoption of home networkingexploded worldwide.Many home networks today still operate using 802.11g routers. At 54 Mbps, these routers can keep up withmost high-speed home internet connections including basic video streaming andonline gaming usages.They can be found inexpensively through bothretail and secondhand sales outlets.
However, G networks can reach performancelimits 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 routersdesigned for fixed installation in homes, 802.11g travel routers also gained substantial popularity withbusiness professionals and families who needed to share a single wired Ethernet connection among their wirelessdevices.
G (and some N) travel routers can still be found in retail outlets buthave become increasingly uncommon as hotel and other public internet servicesshift from Ethernet to wireless hotspots.802.11n is a standard (IEEE) for Wi-Fi wireless local network communications, contract in 2009.802.
11n isdesigned to exchange the 802.11a, 802.11b and 802.11g Wi-Fi technologies. Wireless Technologiesin 802.
11n:802.11n uses multiple wirelessantennas in tandem for transmitting and receiving data. The term MIMO refers to the ability of802.11n and like other technologies to coordinate multiple simultaneous radiosignals. MIMO is used to increase therange and throughput of a wireless network. An other technique employed by802.11n that involves increasing the channel bandwidth.
Such networks 802.11a/b/g, and each .11ndevice that uses a preset Wi-Fi channel on which is used for transmitting. Suchchannel will use a larger frequency range , also increasing data throughput.802.11n Performance:802.
11n connections that supportmaximum theory based network bandwidth upto300 Mbps whichprimarily depends on the number of wireless radios incorporated intodevices.