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Wi-Fi

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Wi-Fi is a family of wireless network protocols used for local area networking.

TP-Link AX1500 Wi-Fi 6 Router Front
TP-Link AX1500 Wi-Fi 6 Router Front

These protocols allow digital devices to exchange data using radio waves. This technology provides internet access in homes, small offices, and public spaces. You can find Wi-Fi in coffee shops, hotels, libraries, and airports. It is one of the most widely used computer networks in the world. Because it is so common, over 3.05 billion Wi-Fi-enabled devices are shipped globally every year.

Metro Wireless Node
Metro Wireless Node

To understand how Wi-Fi works, we must look at radio waves. Devices use specific radio bands, such as the Ultra High Frequency (UHF) and Super High Frequency (SHF) bands. These bands are divided into many different channels.

2.4 GHz spectrum example Screenshot
2.4 GHz spectrum example Screenshot

A single transmitter can use a channel at one time within its range. Radio waves work best with a clear line-of-sight. Physical objects like walls, pillars, or appliances can reduce the signal range. However, these obstructions also help minimize interference between different networks in crowded areas. Newer generations of the standard even use the 6 gigahertz SHF band.

There are different ways for devices to organize themselves on a network. A service set is the collection of all devices associated with a specific network.

SSID ESS
SSID ESS

Each service set has a unique 32-byte identifier called an SSID. One type is a basic service set (BSS), which is a group of stations sharing a channel and SSID. These stations usually connect to the same access point. Devices can also operate in infrastructure mode. In this mode, all communications go through a central base station. Alternatively, devices can use ad hoc mode to communicate directly with each other without an access point.

To connect to a network, a computer needs a wireless network interface controller. The combination of the computer and this controller is called a station.

Every station is identified by one or more MAC addresses. The technology is designed to work well with its wired sibling, Ethernet. While different versions of Wi-Fi use different radio technologies, they are often compatible. This allows devices to network with both wireless access points and wired devices. This connectivity is essential for modern internet access.

The history of Wi-Fi is a global story with many contributors. In 1985, the U.S. Federal Communications Commission released parts of the ISM bands for unlicensed use. These bands include the 2.4 GHz frequency used by microwave ovens. In 1991, the NCR Corporation and AT&T invented WaveLAN in Nieuwegein, Netherlands. This was a precursor to the modern 802.11 standard.

Apple Airport Extreme 802.11g card
Apple Airport Extreme 802.11g card

In Australia, a team at the CSIRO led by John O'Sullivan developed a wireless LAN prototype. They lodged a patent for Wi-Fi in 1992. Because of these developments, Australia, the United States, and the Netherlands all claim to have invented Wi-Fi.

Key individuals helped turn these inventions into a global standard. Vic Hayes and Bruce Tuch worked with the IEEE to design the initial 802.11a and 802.11b specifications. Vic Hayes served as the chair of IEEE 802.11 for ten years. Both men have been inducted into the Wi-Fi NOW Hall of Fame. A major commercial breakthrough occurred in 1999 when Apple adopted Wi-Fi for its iBook laptops.

Apple-Airport-Extreme-80211g-WiFi-Card
Apple-Airport-Extreme-80211g-WiFi-Card

This was the first mass consumer product to offer Wi-Fi connectivity. The Wi-Fi Alliance was also formed in 1999 to manage the trademark.

The Wi-Fi Alliance ensures that different products can work together through certification.

Wifi certified logo
Wifi certified logo

This process is called interoperability testing. If a product passes, it can use the official Wi-Fi logo. The certification requires following IEEE 802.11 radio standards and security standards like WPA and WPA2. The name "Wi-Fi" was actually created by a branding firm called Interbrand. They wanted a name catchier than the technical IEEE 802.11b designation. The name sounds similar to "Hi-Fi," which people associate with high quality.

Modern Wi-Fi continues to evolve with faster speeds and better efficiency. The Wi-Fi Alliance now uses generational numbering to simplify things for users. This includes Wi-Fi 4, Wi-Fi 5, and Wi-Fi 6.

5 GHz Wi-Fi spectrum screenshot
5 GHz Wi-Fi spectrum screenshot

These generations are designed to be backward compatible with older versions. Some versions can achieve speeds of one gigabit per second when running on suitable hardware. Whether it is a small room or many square kilometers, Wi-Fi connects our digital world.

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🖼️ Images & Media (25)
File:TP-Link_AX1500_Wi-Fi_6_Router_Front.jpg
TP-Link_AX1500_Wi-Fi_6_Router_Front.jpg
File:Apple Airport Extreme 802.11g card.jpg
Apple Airport Extreme 802.11g card.jpg
File:Wifi certified logo.png
Wifi certified logo.png
File:SSID ESS.svg
SSID ESS.svg
File:Metro Wireless Node.jpg
Metro Wireless Node.jpg
File:2.4 GHz spectrum example Screenshot.png
2.4 GHz spectrum example Screenshot.png
File:5 GHz Wi-Fi spectrum screenshot.png
5 GHz Wi-Fi spectrum screenshot.png
File:Netgear-Nighthawk-AC1900-WiFi-Router.jpg
Netgear-Nighthawk-AC1900-WiFi-Router.jpg
File:Huawei 4G+ Modem.jpg
Huawei 4G+ Modem.jpg
File:802.11 MAC Frame.svg
802.11 MAC Frame.svg
File:Wi-Fi.gif
Wi-Fi.gif
File:802.11 Beacon frame.gif
802.11 Beacon frame.gif

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