802.11 The evolution of WI-Fi standards: A brief history

1. 802.11
The evolution
of Wi-Fi
BONEY MAUNDU

2. What is IEEE 802.11?
IEEE 802 is a collection of Local Area networking standards that specify and describe communication
protocols for technologies such as Ethernet and wireless.
802.11 is therefore a standard that describes procedures, values, algorithms, and limits to establish a
Wireless Local Area Network connection, what has come to be popularly referred to simply as Wi-Fi.
IEEE 802.11 is the foundation for Wi-Fi devices. The Wi-Fi Alliance owns the trademark Wi-Fi, which verifies the
interoperability of all products using the Wi-Fi trademark using established testing.
Since its inception in 1997, Wi-Fi standards have changed throughout time, bringing with them improvements to data
transfer rates, signal ranges, and connections that are more reliable and secure.
802.11
It’s the pioneering Wi-Fi standard, introduced in 1997 and operating at 2.4 GHz. It’s the basis for all
subsequent Wi-Fi wireless network standards, the world's most widely used wireless computer networking
protocols.
It uses the CSMA/CA protocol (Carrier Sense Multiple Access with Collision Avoidance), which supports
data rates of up to 2 mbps and two transmission technologies: Frequency Hopping Spread Spectrum and
Direct Sequence Spread Spectrum. This standard is now all but obsolete.
802.11b (Wi-Fi 1)
First introduced in 1999, it had a theoretical maximum data rate of 11 Mbps and also used the CSMA/CA
medium access method as its predecessor. The substantial increase in throughput encouraged its wide
uptake as a wireless technology.
This standard shares the same frequency bandwidth as other wireless standards and can be susceptible to signal
interference in a home setting with other wireless devices like cordless phones, microwave ovens, and blue tooth
devices.
802.11a (Wi-Fi 2)
Also introduced in 1999, it operates at 5 GHz and uses Orthogonal Frequency Division Multiplexing (OFDM) with a
maximum theoretical data rate of 54 Mbps.
The 5 GHz frequency gave it a significant advantage over its predecessor with the 2.4 GHz Frequency due
to its lower susceptibility to signal interference, but the downside was that its overall range was shorter,
and it was therefore not widely accepted because of this fact. In addition, 5 GHz devices were costlier and
incompatible with 802.11b.

3. 802.11g (Wi-Fi 3)
Introduced in 2003. Like its predecessor, it uses OFDM and supports a maximum theoretical rate of 54
Mbps, but it operates on a 2.4 GHz frequency, which gives it better range but makes it more susceptible to
interference. It’s also backwards compatible with 802.11b, which means 802.11b devices can connect to an
802.11g access point.
802.11n (Wi-Fi 4)
The introduction of 802.11n in 2009 made Wi-Fi quicker and more dependable by adopting MIMO (Multiple-
Input, Multiple-Output), a technique for increasing a radio link's capacity by using multiple transmit and
receive antennas to take advantage of multipath signal propagation.
It can support maximum theoretical throughput of 600 Mbps and operates on both 2.4 GHz and 5 GHz
frequencies and its backwards compatible to Wi-Fi 3, 2 and 1.
802.11ac (Wi-Fi 5)
It was introduced in 2013 and could support a maximum theoretical throughput of 3.5 Gbps, a feat that
was achieved by improving 802.11n concepts that included wider bandwidth, MU-MIMO (multi-use MIMO),
beam forming, and high density modulations.
Wi-Fi 5 operates exclusively on a 5 GHz frequency.
802.11ax (W-Fi 6)
It’s the sixth generation of Wi-Fi and the most recent, having been introduced in 2021. Its theoretical data
rate is 9.6 Gbps, though its main strength is its ability to work well in places with dense, pervasive Wi-Fi
traffic, like concert halls and stadiums or even homes with a lot of wireless devices, where 2.4 GHz and 5
GHz frequencies would greatly degrade due to over-interference.
It achieves this through denser modulation, mechanisms to support longer-range outdoor deployments,
and reduced subcarrier spacing, even though it operates on both 2.4 GHz and 5 GHz frequencies. It’s also
backwards compatible with 802.11a/g/n/ac devices.
Wi-Fi 6E is an extension of Wi-Fi 6 and uses the 6 GHz frequency band, but it's only limited to 6 GHz-capable
devices and applications.
802.11be (Wi-Fi 7)
Wi-Fi 7, which is still under development, is slated for deployment in 2024 and might achieve data rates of
about 40 Gbps and almost double the bandwidth of Wi-Fi 6.
Wi-Fi 7 technology will be substantially quicker, have much lower latency, support many more devices, and
perform much better in crowded Wi-Fi locations and where Wi-Fi networks overlap as a result of all these
technical advancements.