History of Wifi has a long and fascinating history. ALOHAnet, a UHF wireless packet network, was established in 1971 to connect the Hawaiian Islands. ALOHAnet and the ALOHA protocol were forerunners of Ethernet and, subsequently, the IEEE 802.11 standards.
Vic Hayes, called the “Father of WiFi,” began working on the technology in 1974 when he joined NCR Corp., which is now part of semiconductor components producer Agere Systems.
The U.S. Federal Communications Commission ruled in 1985 that The ISM band – frequencies in the 2.4GHz range – was authorized for unlicensed use by the Federal Communications Commission. These frequency ranges are prone to interference and are utilized by devices such as microwave ovens.
The forerunner of 802.11, designed for use in cashier systems, was created in 1991 by NCR Corporation and AT&T Corporation. WaveLAN was the brand name for the earliest wireless products. Wi-Fi is attributed to them as its creators.
John O’Sullivan, an Australian radio astronomer, together with Terence Percival, Graham Daniels, Diet Ostry, and John Deane created a crucial patent that is used in Wi-Fi as a byproduct of a “A failed effort to detect erupting small black holes the size of an atomic particle,” according to a CSIRO research project.
Finally, Wi-Fi made use of a signal “unsmear” technique created by the CSIRO and given patents in 1992 and 1996. The initial version of the 802.11 protocol, with connection speeds of up to 2 Mbit/s, was published in 1997. With the introduction of 802.11b, which supported 11 Mbit/s connection speeds and was quite popular, this was changed in 1999.
The Wi-Fi Alliance was founded as a trade organisation in 1999 to protect the Wi-Fi trademark, which may be seen on most devices.The brand consultancy firm Interbrand invented the term Wi-Fi, which was first used commercially in August 1999. The Wi-Fi Alliance engaged Interbrand to come up with a name that was “a bit catchier than ‘IEEE 802.11b Direct Sequence.'” According to Phil Belanger, a founding member of the Wi-Fi Alliance who presided over the term “Wi- Fi’s” selection, Interbrand coined Wi-Fi as a play on the word hi-fi. Interbrand also designed the Wi-Fi logo.
The original IEEE 802.11 standard was published in 1997 and updated in 1999, it is already outdated. It included forward error correcting coding and two net bit rates of 1 or 2 megabits per second (Mbit/s). It listed three different physical layer technologies: Direct-sequence spread spectrum (at 1 Mbit/s or 2 Mbit/s), frequency-hopping spread spectrum (at 1 Mbit/s or 2 Mbit/s), and diffuse infrared (at 1 Mbit/s).Microwave transmission over the 2.4 GHz Industrial Scientific Medical frequency band was used in the latter two radio technologies. Earlier WLAN technologies utilized lower frequencies, such as the 900 MHz ISM band in the United States.
The highest raw data rate for 802.11b is 11 Mbit/s, and it uses the same media access method as the original standard. Early 2000 saw the introduction of 802.11b products since it is a direct development of the modulation technique described in the original standard. A large improvement in throughput (relative to the original standard) and concurrently declining prices propelled 802.11b’s quick adoption as the industry’s leading wireless LAN technology.
Other products running in the 2.4 GHz range cause interference to 802.11b devices. Microwave ovens, Bluetooth gadgets, baby monitors, cordless telephones, and certain amateur radio equipment all operate in the 2.4 GHz band.
Clause 18 of the 2012 specification now defines the OFDM waveform at 5.8 GHz, which was first described in clause 17 of the 1999 standard and now contains protocols that provide data transmission and reception at rates ranging from 1.5 to 54 Mbit/s. It has gained widespread acceptance around the world, especially in business contexts.
Although the original amendment is no longer valid, manufacturers of wireless access points (cards and routers) nevertheless refer to the interoperability of their systems at 5 GHz, 54 Mbit/s by using the label 802.11a.
The 802.11a standard employs the same data link layer protocol and frame structure as the original standard, but the air interface is based on OFDM (physical layer). It runs in the 5 GHz spectrum and has a maximum net data rate of 54 Mbit/s plus error correcting coding, resulting in real net achievable throughput in the mid-20 Mbit/s range.
A third modulation standard, 802.11g, was approved in June 2003. This employs the same OFDM-based transmission technique as 802.11a and operates in the 2.4 GHz range (like 802.11b). It has a maximum physical layer bit rate of 54 Mbit/s, or around 22 Mbit/s average throughputs, excluding forward error-correcting codes.
Because 802.11g technology is backward compatible with 802.11b gear, it is plagued by legacy faults that limit throughput by 21% compared to 802.11a.
Due to the desire for faster data speeds and lower manufacturing costs, the then-proposed 802.11g standard was quickly adopted in the market beginning in January 2003, well before ratification. Most dual-band 802.11a/b systems had become dual-band/tri-mode by the summer of 2003, enabling customers to utilize both a and b/g on a single mobile adapter card or access point.
The remaining technical development was mostly focused on making b and g operate well together, however in an 802.11g network, an 802.11b participant’s activities would reduce the network’s overall transmission rate.
802.11g devices, like 802.11b, suffer from interference from other 2.4 GHz-based items, such as wireless keyboards.
Many of the modifications to the 1999 version of the 802.11 standards were “rolled up” in 2003 by task group TGma. REVma, or 802.11ma, was a single document that combined eight modifications with the base standard . On March 8, 2007, 802.11REVma renamed the current base standard to IEEE 802.11-2007.
802.11n is an upgrade to the earlier 802.11 standards, including multiple-input, multiple-output antennas (MIMO). 802.11n uses both the 2.4 GHz and 5 GHz bands. Optional 5 GHz band support is available. It has a maximum net data rate of 54 to 600 megabits per second. The change was accepted by the IEEE and published in October 2009.
Enterprises were already shifting to 802.11n networks before the final ratification, based on the Wi-Fi Alliance’s certification of equipment adhering to a 2007 draft of the 802.11n proposal.
Many of the 2007 version of the 802.11 standard revisions were “rolled up” by task group TGmb in May 2007. REVmb, or 802.11mb, was a single document that combined 10 modifications with the 2007 base standard (802.11k, r, y, n, w, p, z, v, u, s). A lot of cleaning was also done, including rearranging several of the sentences. The revised standard was given the name IEEE 802.11-2012 when it was published on March 29, 2012.
An upgrade to IEEE 802.11, known as IEEE 802.11ac-2013, was made in December 2013. Improvements over 802.11n include wider 5 GHz channels (80 or 160 MHz against 40 MHz), higher-order modulation (up to 256-QAM), more spatial streams (up to eight vs four), versus 64-QAM), and the addition of Multi-user MIMO (MU-MIMO).As of October 2013, high-end implementations in the 5 GHz band enable 80 MHz channels, three spatial streams, and 256-QAM, resulting in a data throughput of up to 433.3 Mbit/s per spatial stream 1300 Mbit/s altogether.
In 2014 and 2015, vendors aim to deliver so-called “Wave 2” devices that enable 160 MHz channels, four spatial streams, and MU-MIMO.
IEEE 802.11ad specifies a new physical layer for 802.11 networks operating in the 60 GHz millimeter wave range. This frequency spectrum’s propagation characteristics are very different from those of the 2.4 GHz and 5 GHz bands, where Wi-Fi networks operate.
The WiGig brand is being used to promote products that use the 802.11ad standard. Instead of the now-defunct WiGig Alliance, the Wi-Fi Alliance is developing a certification scheme. 802.11ad has a maximum transmission rate of 7 Gbit/s.
5GHz or 2.4GHz : Best WiFi FrequencyWhat is the best WiFi frequency, 5GHz or 2.4GHz? The solution would rely on your network requirements. You could ask what WiFi frequency is optimal for your network installations while creating a WLAN. This article will help you decide if it is better to give a dependable wireless experience using the 2.4 GHz or 5 GHz band frequency.
The IEEE 802.11af amendment, often known as “White-Fi” or “Super Wi-Fi,” was accepted in February 2014 and permits WLAN operation in the TV white space spectrum between 54 and 790 MHz.
It transmits over vacant TV channels using cognitive radio technology, with the standard taking precautions to avoid interference with primary users such as analog TV, digital TV, and wireless microphones.
Access points and stations employ a satellite positioning system such as GPS to detect their location. They then use the Internet to query a geolocation database (GDB) maintained by a regional regulatory body to determine which frequency channels are accessible for usage at a given time and location. The physical layer is based on 802.11ac and employs OFDM.
Greater range is possible in the UHF and VHF bands due to reduced propagation path loss and attenuation by building materials like brick and concrete than in the 2.4 and 5 GHz frequencies. The width of the frequency channels varies from 6 to 8 MHz depending on the regulating authority. One or two continuous blocks can be used to connect up to four channels.
In MIMO, up to four streams can be employed for either space-time block coding (STBC) or multi-user (MU) operation. The data rate per spatial stream for 6 and 7 MHz channels is 26.7 Mbit/s and 35.6 Mbit/s for 8 MHz channels. The highest data rate for 6 and 7 MHz channels and 568.9 Mbit/s for 8 MHz channels while using four spatial streams and four bonded channels is 426.7 Mbit/s.