At a base level, WiFi is a way of getting broadband internet to a device using wireless transmitters and radio signals. Once a transmitter receives data from the internet, it converts the data into a radio signal that can be received and read by WiFi enabled devices. Information is then exchanged between the transmitter and the device.
This is technology that allows a PC, laptop, mobile phone, or tablet device to connect at high speed to the internet without the need for a physical wired connection.
How it works?
A small device known as a wireless transmitter, or hub, is required which receives information from the internet via a broadband connection. This transmitter (often referred to as a Wireless Access Point, or WAP) then converts this information into radio waves and emits it, effectively creating a small, local area around itself, within which devices can receive these radio signals if they are fitted with the correct kind of wireless adapter. This area is often termed a Wireless Local Area Network, or WLAN for short. The radio signals aren’t very strong, which is why the Wi-Fi signal doesn’t travel very far; it will travel far enough to cover throughout the average home and to the street directly outside, for example, but not much further. One wireless hub is usually enough to enable you to connect to the internet in any room in a building, though the signal will be stronger the nearer the hub you are.
Since its inception, WiFi has played an integral role in keeping us connected at home and in public. We’ve come to expect a standard degree of connectivity wherever we go, and regularly rely on WiFi to maintain our productivity, our organization, our health, and even our protection. Recent advances in WiFi technology has greatly contributed to the Internet of Things, allowing us to be even more connected than ever before.
In 1971, ALOHAnet connected the Hawaiian Islands with a UHF wireless packet network. ALOHAnet and the ALOHA protocol were early forerunners to Ethernet, and later the IEEE 802.11 protocols, respectively.
Vic Hayes is often regarded as the “father of Wi-Fi.” He started such work in 1974 when he joined NCR Corp., now part of semiconductor components maker Agere Systems.
A 1985 ruling by the U.S. Federal Communications Commission released the ISM band for unlicensed use – these are frequencies in the 2.4GHz band. These frequency bands are the same ones used by equipment such as microwave ovens and are subject to interference.
In 1991, NCR Corporation with AT&T Corporation invented the precursor to 802.11, intended for use in cashier systems. The first wireless products were under the name WaveLAN. They are the ones credited with inventing Wi-Fi.
In 1992 and 1996, CSIRO obtained patents for a method later used in Wi-Fi to “unsmear” the signal.
The first version of the 802.11 protocol was released in 1997 first released for consumers, and provided up to 2 Mbit/s link speeds. This sparked a development in prototype equipment (routers) to comply with IEEE802.11, and was updated in 1999 with 802.11b to permit 11 Mbit/s link speeds, and this proved to be popular and also WiFi was introduced for home use.
WiFi uses electromagnetic waves to communicate data that run at two main frequencies: 2.4Ghz (802.11b) and 5Ghz (802.11a). For many years, 2.4Ghz was a popular choice for WiFi users, as it worked with most mainstream devices and was less expensive than 11a.
In 2003, faster speeds and distance coverage of the earlier WiFi versions combined to make the 802.11g standard. The then-proposed 802.11g standard was rapidly adopted in the market starting in January 2003, well before ratification, due to the desire for higher data rates as well as to reductions in manufacturing costs. Routers were getting better too, with higher power and further coverage than ever before. WiFi was beginning to catch up – competing with the speed of the fastest wired connections. By summer 2003, most dual-band 802.11a/b products became dual-band/tri-mode, supporting a and b/g in a single mobile adapter card or access point. Details of making b and g work well together occupied much of the lingering technical process; in an 802.11g network, however, activity of an 802.11b participant will reduce the data rate of the overall 802.11g network.
2009 saw the final version of the 802.11n, which was even faster and more reliable than its predecessor. 802.11n was an amendment that improves upon the previous 802.11 standards by adding output antennas (MIMO). 802.11n operates on both the 2.4 GHz and the 5 GHz bands. Support for 5 GHz bands was optional. It operates at a maximum net data rate from 54 Mbit/s to 600 Mbit/s. This allowed for significant increases in data without the need for higher bandwidth or transmit power. The IEEE has approved the amendment, and it was published in October 2009.
The 2.4 Ghz extended range meant that an increasing number of devices (from baby monitors to bluetooth) were using the same frequency, causing it to become overcrowded and slower. Consequently, 5Ghz became the more attractive option.
Simultaneous Dual-Band Routers
To solve this issue, dual-band routers were created. These routers contained two types of wireless radios that could simultaneously support connections on both 2.4 GHz and 5GHz links. By default, devices in range of a dual-band router would automatically connect to the faster, more efficient 5GHz frequency. However, if a device was further away or behind walls, the 2.4Ghz could be used as a backup.
801.11ac aimed to make the 5Ghz range better: it had four times the speed of WiFi 801.11n, a greater width, and the ability to support more antennas, meaning data could be sent more quickly. 2012 also saw the birth of the Beamforming concept, which is explained by Eric Geier as focusing signals and concentrating data transmission so that more data reaches the target device. He notes: ‘Instead of broadcasting a signal to a wide area, hoping to reach your target, why not concentrate the signal and aim it directly at the target?’
Future WiFi enhancements and upgrades:
IEEE 802.11ah defines a WLAN system operating at sub-1 GHz license-exempt bands, with final approval slated for September 2016.
Due to the favourable propagation characteristics of the low frequency spectra, 802.11ah can provide improved transmission range compared with the conventional 802.11 WLANs operating in the 2.4 GHz and 5 GHz bands. 802.11ah can be used for various purposes including large scale sensor networks, extended range hotspot, and outdoor Wi-Fi for cellular traffic offloading, whereas the available bandwidth is relatively narrow. The protocol intends consumption to be competitive with low power Bluetooth, at a much wider range.
IEEE 802.11ai is an amendment to the 802.11 standard that will add new mechanisms for a faster initial link setup time.
IEEE 802.11aj is a rebanding of 802.11ad for use in the 45 GHz unlicensed spectrum available in some regions of the world (specifically China).
IEEE 802.11aq is an amendment to the 802.11 standard that will enable pre-association discovery of services. This extends some of the mechanisms in 802.11u that enabled device discovery to further discover the services running on a device, or provided by a network.
IEEE 802.11ax is the successor to 802.11ac, and will increase the efficiency of WLAN networks. Currently in development, this project has the goal of providing 4x the throughput of 802.11ac.
IEEE 802.11ay is a standard that is being developed. It is an amendment that defines a new physical layer for 802.11 networks to operate in the 60 GHz millimeter wave spectrum. It will be an extension of the existing 11ad, aimed to extend the throughput, range and use-cases. The main use-cases include: indoor operation, out-door back-haul and short range communications. The peak transmission rate of 802.11ay is 20 Gbit/s. The main extensions include: channel bonding (2, 3 and 4), MIMO and higher modulation schemes.
IEEE 802.11-2016 is a revision based on IEEE 802.11-2012, incorporating 5 amendments (11ae, 11aa, 11ad, 11ac, 11af). In addition, existing MAC and PHY functions have been enhanced and obsolete features were removed or marked for removal. Some clauses and annexes have been renumbered.
Outdoor Grade WiFi and Hotspots
Some vendors have extended WiFi technology to include Outdoor WiFi and proprietary extensions such as Mesh and other features. These devices allow greater use access to WiFi in public spaces.
The use of WiFi today is summed up nicely by Rethink Wireless: “WiFi performance continues to improve and it’s one of the most ubiquitous wireless communications technologies in use today. It’s easy to install, simple to use and economical too. WiFi Access Points are now set up at home and in public hotspots, giving convenient internet access to everything from laptops to smartphones. Encryption technologies make WiFi secure, keeping out unwanted intruders from these wireless communications.”
But WiFi is more about simply getting online to check email or browse social feeds. It has also enabled a mind-blowing number of consumer electronics and computing devices to become interconnected and exchange information – a phenomenon known as Internet of Things. According to Wi-FI.org, the IoT is “one of the most exciting waves of innovation the world has witnessed” and that “its potential has only just begun to emerge.”
It’s clear that WiFi is no longer a one-way street – it has become an essential part of our personal and professional day-to-day, and is constantly improving our efficiency, our communication, and is persistently encourages the technology industry to push the boundaries of what’s possible.
All in all, the capabilities of WiFi are endless, and with the way things are going, we are incredibly excited to see what the future holds.