WiFi is a term that everybody knows about nowadays and has become an integral part of everyday life. From our smartphones, to game consoles and computers, most devices on the market today are equipped with WiFi.
What is WiFi?
For most people, WiFi is associated with internet connection. However, this is not the case. WiFi is actually a wireless standard for connecting to the internet from your device. Basically, instead of connecting to a device via wired network, you are connecting via a wireless network. The actual connection does not need to be towards the internet per se, rather, WiFi is a means of network communication without using wires.
History of WiFi
WiFi was born in 1985, when the USA FCC opened up the wireless frequencies of 900MHz, 2.4GHz, and 5.8GHz to be used without a license. These bands were used by household appliances such as microwaves, so it was assumed that there was no practical application in communications due to the large potential for interference with such appliances. To make these frequencies useable for communication, the FCC mandated the usage of spread spectrum technology over these bands.
Spread Spectrum Technology
Spread spectrum technology is a technology in which a signal is spread over multiple frequencies in order to reduce interference. Spread spectrum improved the wireless signals on these bands quite a bit, however, it did not resolve all the problems. Baby monitors or the radio in phones still affected the signal quality of WiFi using this technology.
WLAN (Wireless Local Area Network) technology emerged at this time as well. As the technology was still proprietary, wireless devices from one manufacturer did not work with technology from another. However, this would not last long. In 1988, the NCR Corporation wanted to use a WLAN standard in their wireless cash registers. Victor Hayes, along with Bruce Tuch, a Bell Labs engineer, asked the Institute of Electrical and Electronic Engineers (IEEE) for assistance in utilizing these frequencies for a WLAN standard. A committee was created with the title “802.11” to develop this standard. In 1997, after nine years, the standard was published and was named IEEE802.11, after the committee itself.
The 802.11 standard was capable of transmitting data at a speed of only 2 megabits per second. This was quite an achievement for the time but a faster version was released in 1999, called 802.11a. This had a speed of 54 megabits per second, but it suffered from very limited range and high cost because it used 5GHz frequency. The large frequency meant that it was absorbed more readily by walls than 2.4GHz radio frequencies, which would penetrate more easily through walls.
However, later in 1999, 802.11b was released. This was the true birth of WiFi as we know it because it brought it into the mainstream. It was much cheaper to produce and had much greater range because it used the 2.4GHz frequency spectrum. It also reduced the speeds achieved according to the signal strengths. It could go between 1Mbit/s to 11Mbit/s dynamically according to signal strength.
In June 2003, 802.11g was produced. This had a speed of 54Mbit/s like 802.1a, but worked on the 2.4GHz band instead of the 5GHz band, so it did not have the range issues of 802.1a. What’s more, 802.11g hardware is backward-compatible with 802.11b, so it can reduce the speed according to signal strength to 1Mb/s dynamically.
Wireless networking became extremely popular at this time and created a flood of new hardware on the market. However, there was no way to ensure compatibility between devices from different manufacturers. In 1999, a group of six companies banded together to create the Wireless Ethernet Compatibility Alliance, or WECA, an organization that aimed to test WiFi equipment for compatibility. In 2002, they coined the term WiFi, a combination of the words “Wireless” and “HiFi”, a term used in the music industry as an abbreviation of High Fidelity. They renamed themselves WiFi Alliance. Over the years, notably due to Apple’s inclusion of it into their products, WiFi gradually became a widespread technology.
Wireless N and AC… MIMO
Wireless N was released in 2009 and is innovative due to the fact that it utilises a technology called MIMO. MIMO stands for “Multiple In, Multiple Out”. Basically, Wireless N uses the 802.1a, b and g technology but using multiple antennas, creating more bandwidth in the process. This brought the speed up to 600Mbit/s.
Wireless AC is the newest WiFi standard which was released in 2014. This operates on the 5GHz band and also uses MIMO. One can have from 4 to 8 antennas in Wireless AC to utilise multi-user MIMO. Multi-user MIMO is when up to 4 separate controllers can receive and send data simultaneously. This increases the link speed considerably up to a massive 1Gbit/s and more.
Future WiFi standards
Future protocols in the pipeline will be extensions of the 802.11ac standard. The successor of 802.11ac will be 802.11ax. This will increase the efficiency of the WLAN networks to provide the goal of 4 times the throughput of 802.11ac.
Having WiFi performance and efficiency improved over the years will enable the realisation of having true IoT (Internet of Things) across the world, where all the appliances, including your refrigerator, fan, coffee machine etc. will be connected to the internet and can be controlled through devices such as mobile phones or computers.