Wi-Fi works by a router sending and receiving data as radio waves to the wireless adapters in your devices.
Basics
Wi-Fi sends data as radio waves between a wireless router and device adapters. The router connects to the internet via a modem.
Frequencies
Wi-Fi uses 2.4 GHz, 5 GHz and 6 GHz bands. The 2.4 GHz band has longer range, and 5 and 6 GHz are faster.
Standards
IEEE 802.11: Wi-Fi 4 (n), 5 (ac), 6 (ax), 7 (be).
Steps
- Your device encodes data into radio signals.
- The router receives, decodes and passes it to the internet.
- The reply returns the same way.
Security
WPA2 and WPA3 encrypt traffic.
Range
Typically 150 feet indoors.
Interference
Walls, microwaves and other networks reduce speed.
Basic idea
Wi-Fi is a wireless technology that uses radio waves to move data between a device and a router, which is connected to the internet by cable or fiber. Information is split into packets, turned into radio signals and sent over a channel. The name Wi-Fi is a trademark of the Wi-Fi Alliance, which certifies devices that follow the IEEE 802.11 standards.
Frequencies
Wi-Fi uses three main bands. The 2.4 GHz band reaches farther and passes through walls better, but is slower and crowded. The 5 GHz band offers higher speeds over shorter ranges. The 6 GHz band, added with Wi-Fi 6E, has the most free channels and lowest interference, with the shortest range. Wi-Fi 7 uses all three bands together.
Standards and speeds
- Wi-Fi 4 (802.11n, 2009): up to 600 Mbps in theory.
- Wi-Fi 5 (802.11ac, 2014): up to about 3.5 Gbps.
- Wi-Fi 6 (802.11ax, 2019): up to about 9.6 Gbps, and better handling of many devices.
- Wi-Fi 6E: Wi-Fi 6 with the 6 GHz band.
- Wi-Fi 7 (802.11be, 2024): up to about 46 Gbps in theory.
Real speeds are far lower than the theoretical maximums, often half or less.
How a connection forms
A device scans for networks, which advertise by name (SSID). It sends an authentication request and then associates with the router. After exchanging security keys, the router assigns an IP address using DHCP. Data is then sent in frames, with devices taking turns on the channel and checking for collisions.
Security
WPA3, introduced in 2018, is the current standard and protects against password guessing attacks. WPA2 with AES is still acceptable. WEP and the original WPA are broken and should not be used. Use a long, unique password, change the default router login, update firmware, and turn off WPS.
Range
A typical home router covers 30 to 50 meters indoors at 2.4 GHz and around 15 to 25 meters at 5 GHz. Walls, floors, metal and water reduce signal. Place the router in a central, elevated location, and use mesh systems or access points for larger homes.
Interference
Microwaves, Bluetooth devices, cordless phones and neighboring networks on the same channel can reduce performance. Choose less crowded channels, use 5 GHz for close devices, and keep the router away from other electronics.
Health
Wi-Fi uses non-ionizing radiation at a power far lower than a cell phone, usually under 100 milliwatts, and the World Health Organization has found no confirmed health effects at these levels.
Channels and standards in numbers
Wi-Fi works by sending data as radio waves between a router and devices. Routers use 2.4 GHz, 5 GHz and, with Wi-Fi 6E and 7, 6 GHz bands. Wi-Fi 4 (802.11n) reaches up to 600 Mbps in theory, Wi-Fi 5 (802.11ac) up to 3.5 Gbps, Wi-Fi 6 (802.11ax) up to 9.6 Gbps and Wi-Fi 7 (802.11be) up to 46 Gbps. The 2.4 GHz band travels farther but is slower and crowded with only three non-overlapping channels (1, 6 and 11 in the US). WPA3 is the current security standard, and WEP is obsolete and easily cracked. Place the router centrally and off the floor to improve coverage. The Wi-Fi Alliance introduced the brand in 1999.
Based on data from the Wi-Fi Alliance and IEEE standards
