How Does Wi-Fi Work?

What Wi-Fi is and how the parts fit together

Wi-Fi is a wireless local area network (WLAN) technology, based on the IEEE 802.11 standards, that lets devices within a certain area communicate using radio waves.^[1] The first 802.11 standard was published in 1997 and sent data at up to 2 megabits per second (Mbit/s) over unlicensed radio spectrum at 2.4 GHz.^[1]

The 802.11 standard has two basic building blocks.^[6] The devices, which NIST calls stations, are wireless endpoints such as laptops and mobile phones.^[6] An access point connects them to a distribution system, usually a wired network, which is how they reach outside networks such as the internet.^[6] Devices can also link directly without an access point, in what is called ad hoc mode, but the access-point setup is the most common.^[6] The FCC says most households with home internet service use the Wi-Fi on their home router.^[5]

2.4 GHz, 5 GHz and 6 GHz: range versus speed

Modern routers often broadcast two or more Wi-Fi signals, one in the 2.4 GHz band and one in the 5 GHz band.^[5] According to the FCC, 2.4 GHz connections generally cover a wider area but move data less quickly, while 5 GHz connections are faster but reach a shorter range.^[5] Many household devices also use 2.4 GHz, and the 5 GHz band may be less crowded by neighboring networks.^[5] The IEEE notes that the 802.11b version of Wi-Fi used special modulation schemes partly to reduce interference from microwave ovens, cordless phones and baby monitors.^[1]

Wi-Fi 6 added a third band, 6 GHz, to the 2.4 and 5 GHz bands of earlier generations.^[2] In the United States, the FCC adopted rules on April 23, 2020, that made 1,200 megahertz of spectrum between 5.925 and 7.125 GHz available for unlicensed use, which it said would increase the spectrum available for Wi-Fi by nearly a factor of five.^[4] Those rules let low-power indoor devices use all 1,200 megahertz and standard-power access points use 850 megahertz, with an automated coordination system to keep them from interfering with existing users of the band, such as microwave links for utilities and public safety.^[4]

The Wi-Fi Alliance, a non-profit industry group of equipment and software makers, says 6 GHz suits Wi-Fi because it sits next to the 5 GHz band, has room for wider channels and has less interference from older Wi-Fi 4 and Wi-Fi 5 devices.^[3][6] It counted space for 14 extra 80 MHz channels and 7 extra 160 MHz channels.^[3] Outside these three bands, the Alliance also certifies Wi-Fi HaLow, which uses spectrum below 1 GHz for long-range, low-power sensors, and WiGig, which uses the 60 GHz band.^[2]

How far Wi-Fi reaches and why walls weaken it

Wi-Fi networks serve devices within a fairly limited range, such as an office building.^[6] The IEEE gave the reach of the early 802.11b version as about 38 meters indoors and about 140 meters outdoors.^[1]

Building materials also weaken the signal.^[7] In a 1997 report, the U.S. National Institute of Standards and Technology (NIST) measured signal loss through brick, masonry block, concrete, glass, plywood, lumber, drywall and reinforced concrete, at frequencies from 0.5 to 2 GHz and from 3 to 8 GHz.^[7] It found that, in general, the loss per millimeter of material increases as the frequency rises, so higher-frequency signals tend to lose more strength passing through the same wall.^[7]

Wi-Fi 4, 5, 6, 6E and 7: what the numbers mean

To help the public tell the IEEE versions apart, the Wi-Fi Alliance created generation names.^[1]

Dates differ by source: the IEEE says 802.11ac was introduced in 2013 and 802.11ax was published in 2021, while the Wi-Fi Alliance dates Wi-Fi 5 to 2014 and Wi-Fi 6 to 2018.^[1][2] The IEEE approved 802.11be, the standard behind Wi-Fi 7, in September 2024 and published it in July 2025; it defines at least one mode with a maximum throughput of at least 30 Gbit/s.^[1][9] The Alliance's current generations page also lists 6 GHz under Wi-Fi 6 itself, although its 2020 announcement introduced Wi-Fi 6E as the name for Wi-Fi 6 devices that can use 6 GHz.^[2][3] The IEEE says each 802.11 amendment is designed to be backward compatible, so a modern device can communicate with older products.^[1]

Wi-Fi 6 was not mainly about raw speed: it targets crowded places, such as stadiums and homes full of gadgets, by splitting its capacity among many devices.^[1] Wi-Fi 7 doubles the widest channel to 320 MHz, from 160 MHz in Wi-Fi 6, and the Wi-Fi Alliance says these channels give twice the throughput of Wi-Fi 6.^[1][2] The Alliance describes Wi-Fi 8 as the next generation, focused on reliability.^[2]

The chart shows the maximum or theoretical rates the IEEE gives in its history of the standards, with gigabit figures converted to Mbit/s.^[1]

• 802.11 (1997)2 Mbit/s
• 802.11b (1999)11 Mbit/s
• 802.11g (2003)54 Mbit/s
• 802.11n (2009)600 Mbit/s
• 802.11ac (2013)3,500 Mbit/s
• 802.11ax (2021)9,600 Mbit/s

Source: IEEE Standards Association [1]

How WPA2 and WPA3 keep Wi-Fi private

NIST notes that most wireless network threats involve an attacker with access to the radio link between a device and its access point, and that wireless traffic is relatively easy to intercept.^[6] Early Wi-Fi relied on a security method called Wired Equivalent Privacy (WEP), which has several well-documented security problems.^[6] To fix them, the IEEE approved the 802.11i amendment in 2004, and in September 2004 the Wi-Fi Alliance launched WPA2, its certification for products that support the complete 802.11i standard.^[6] 802.11i defines two protocols for keeping data confidential and intact, TKIP and CCMP, and only CCMP uses the Advanced Encryption Standard (AES).^[6]

On June 25, 2018, the Wi-Fi Alliance introduced WPA3 as the next generation of Wi-Fi security, building on more than a decade of WPA2 use.^[8] WPA3-Personal, for password-protected networks, uses a key-exchange method called Simultaneous Authentication of Equals (SAE) to give stronger protection against people trying to guess the password.^[8] WPA3-Enterprise offers the equivalent of 192-bit cryptographic strength for networks carrying sensitive data, such as in government or finance.^[8] WPA3 still works with WPA2 devices through a transitional mode.^[8]