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Wi-Fi

lastmod 2026-08-28created 2017-03-0227 edits

Wi-Fi (WiFi) is a technology that allows electronic devices to connect to a wireless LAN (WLAN), mainly using the 2.4 gigahertz (12 centimeter) UHF and 5 gigahertz (6 centimeter) SHF ISM radio bands. A WLAN is usually password-protected, but it can also be left open so that any device within range can access the resources of the WLAN network.

The Wi-Fi Alliance defines Wi-Fi as any "wireless local area network" (WLAN) product based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards. Wi-Fi is a trademark of the Wi-Fi Alliance. The Wi-Fi Certified trademark can be used only by Wi-Fi products that have fully passed the Wi-Fi Alliance interoperability certification testing.

Devices that use Wi-Fi technology include personal computers, video game consoles, smartphones, digital cameras, tablet computers, digital audio players, and modern printers. Wi-Fi compatible devices can connect to the Internet via a WLAN network and a wireless access point. Such an access point (hotspot) has a range of about 20 meters (66 feet) indoors and a greater range outdoors. Hotspot coverage can be as small as a single room with walls that block radio waves, or as large as several square kilometers by using multiple overlapping access points.

Wi-Fi tends to be less secure than wired connections such as Ethernet, because an intruder does not need a physical connection. Web pages that use TLS are secure, but unencrypted Internet access can easily be detected by intruders. For this reason, Wi-Fi has adopted various encryption technologies. The early encryption, WEP, could be broken easily. Higher-quality protocols (WPA, WPA2) were added later. Wi-Fi Protected Setup (WPS), an optional feature added in 2007, had a serious flaw that allowed an attacker to recover the router's password. Since then, the Wi-Fi Alliance has updated its test plan and certification program to ensure that newly certified devices resist the attack.

How to check device information

You can print a list using nmcli. 

nmcli device wifi list

To check the Wi-Fi standard (802.11a/b/g/n/ac/ax, etc.) with the iw command, you can use the following command: 

iw list

This command prints detailed information about the wireless interface. In the output, look for the "Supported interface modes" or "Supported bands" sections. There you can check the supported frequency bands (2.4GHz or 5GHz), maximum speed, and channel bandwidth. Also, if an entry such as HE (High Efficiency) appears, it means Wi-Fi 6 (Wi-Fi 802.11ax) is supported.

The iwconfig command shows the wireless settings of network interfaces. However, it does not provide detailed information, so it is mainly useful for quickly checking basic information about a wireless interface. 

iwconfig

The lshw command shows hardware information for network devices. Another approach is to check the model name and manufacturer of the wireless device and search the Internet for its specs. 

sudo lshw -C network

Peak wireless speed

Peak wireless speed refers not to the sum of the speeds supported on the 2.4GHZ, 5GHz, and 6GHz frequencies, but to the speed of the fastest radio frequency supported on a single frequency.

The peak wireless speed for each wireless standard is as follows:

Router single peak speed by wireless standard (edit)

Wireless standard

Single peak speed

  • BE33000

11520Mbps

  • AXE16000
  • AXE11000
  • AXE6600
  • AX11000
  • AX9000
  • AX6600
  • AX6000
  • AX5700
  • AX5400

4804Mbps

  • AXE5400
  • AX5300
  • AX4200
  • AX3000

2402Mbps

  • AC5300
  • AC3150
  • AC3100
  • AC2900

2167Mbps

  • AC4300
  • AC3000
  • AC2600
  • AC2400
  • AC2000

1733Mbps

  • AC2300

1625Mbps

  • AC3200
  • AC2200
  • AC1900
  • AC1750
  • AC1700
  • AC1600

1300Mbps

  • AX1800
  • AX1500

1201Mbps

  • AC2100
  • AC1500
  • AC1350
  • AC1300
  • AC1200

867Mbps

  • N900
  • N750
  • N450

450Mbps

  • AC750
  • AC600

433Mbps

  • N600
  • N300

300Mbps

  • N150

150Mbps

Maximum supported wireless speed

This indicates the maximum speed a wireless device supports, expressed as the sum of the 802.11n and 802.11ac standard speeds.

Since the maximum supported speed is the sum of the speeds of all supported standards, the speed of a single device may be lower than the maximum supported speed.

#Wi-Fi 7
Prefixed with "BE".
BE33000, BE30000, BE25000, BE19000, BE11000, BE9700, BE9300, BE7200, BE6800, BE6500, BE5000, BE3600
#Wi-Fi 6E
Prefixed with "AXE".
AXE16000, AXE11000, AXE7800, AXE6600, AXE5400, AX7800
#Wi-Fi 6
Prefixed with "AX".
AX11000, AX9000, AX6600, AX6000, AX5700, AX5400, AX4200, AX3600, AX3200, AX3000, AX2700, AX1800, AX1500
#Wi-Fi 5
Prefixed with "AC".
AC4300, AC3200, AC3150, AC3000, AC2600, AC2400, AC2300, AC2200, AC2100, AC2000, AC1900, AC1750, AC1600, AC1350, AC1300, AC1200, AC900, AC750
#Wi-Fi 4
Prefixed with "N".
N900, N450, N300, N150

Others: G54 and below

Performance comparison

Feature

802.11ac (Wi-Fi 5)

802.11ax (Wi-Fi 6)

802.11ax with 6GHz (Wi-Fi 6E)

802.11be (Wi-Fi 7)

Frequency band

5GHz

Supports both 2.4GHz and 5GHz

2.4GHz, 5GHz, plus 6GHz

2.4GHz, 5GHz, 6GHz

Maximum theoretical speed

Up to 3.5 Gbps

Up to 9.6 Gbps

Up to 9.6 Gbps

Up to 46 Gbps

Channel efficiency

Low; the AP cannot communicate with multiple devices simultaneously

Can communicate with multiple devices simultaneously via OFDMA

Can handle more devices with OFDMA and the 6GHz band

Band aggregation and optimization via MLO (Multi-Link Operation)

Battery efficiency

No battery-saving features

Battery saving via the TWT (Target Wake Time) feature

TWT support, even more efficient with the 6GHz band

TWT and further improved power saving

MU-MIMO

Downlink only

Supports both uplink and downlink

Supports uplink and downlink

Enhanced MU-MIMO, supports more simultaneous connections

Congestion management

Performance degrades in congested environments

BSS Coloring improves performance even in congested network environments

The 6GHz band reduces interference and allows wider channels

Adds improved BSS Coloring, Preamble Puncturing, and more

Interference reduction

High chance of interference

Improved interference reduction

Minimal interference with the 6GHz band

Reduced interference and maximized speed by using multiple frequency bands simultaneously

Real-world use cases

Suitable for typical home networks and basic streaming

Suitable for IoT, smart homes, high-speed game streaming, and environments with many connections

Suitable for high-bandwidth environments such as ultra-fast connections, AR/VR, and smart cities

Ideal for ultra-high-resolution video, AR/VR, and large-scale IoT environments

Wi-Fi Generations Comparison

Generation

IEEE Standard

Adopted

Maximum Link Rate (Mb/s)

Radio Frequency (GHz)

(Wi-Fi 0*)

802.11

1997

1–2

2.4

(Wi-Fi 1*)

802.11b

1999

1–11

2.4

(Wi-Fi 2*)

802.11a

1999

6–54

5

(Wi-Fi 3*)

802.11g

2003

1–54

2.4

Wi-Fi 4

802.11n

2009

6.5–600

2.4, 5

Wi-Fi 5

802.11ac

2013

6.5–6933

5

Wi-Fi 6

802.11ax

2021

0.4–9608

2.4, 5

Wi-Fi 6E

802.11ax

2021

0.4–9608

2.4, 5, 6

Wi-Fi 7

802.11be

exp. 2024

0.4–23,059

2.4, 5, 6

Wi-Fi 8

802.11bn

exp. 2028

100,000

2.4, 5, 6

  • Wi‑Fi 0, 1, 2, 3 were named by retroactive inference. They do not exist in the official nomenclature.

Versions and generations

The most important standards affecting Wi-Fi are as follows

  • 802.11a
  • 802.11b
  • 802.11g
  • 802.11n (Wi-Fi 4)
  • 802.11h
  • 802.11i
  • 802.11-2007
  • 802.11–2012
  • 802.11ac (Wi-Fi 5)
  • 802.11ad
  • 802.11af
  • 802.11-2016
  • 802.11ah
  • 802.11ai
  • 802.11aj
  • 802.11aq
  • 802.11ax (Wi-Fi 6)
  • ???
  • 802.11ax with 6GHz (Wi-Fi 6E)
  • ???
  • 802.11ay
  • ???
  • 802.11be (Wi-Fi 7)
  • ???

Wi-Fi 7

Uses "BE".

Wi-Fi 6E

Uses "AXE".

Wi-Fi 6

Uses "AX". Also called HE (High Efficiency).

Wi-Fi 5

Uses "AC".

Wi-Fi 4

Uses "N".

OFDMA

See Orthogonal frequency-division multiple access.

Wi-fi location tracking

A browser's location permission request does not just estimate location from the IP; it performs precise positioning using information about nearby Wi-Fi access points

  • In this process, the browser collects data such as SSID, BSSID, and signal strength (RSSI) and matches it against the databases of service providers such as Google
  • These databases were built through past wardriving and continuous data transmission from users' devices
  • There have been several privacy controversies, such as the incident in which Google Street View cars collected unencrypted data
  • Today most devices use this system by default; you can opt out by registering your BSSID or adding ‘_nomap’ to your SSID

How useful is hiding the SSID for security?

Hiding the SSID is almost meaningless for security and even has some slight drawbacks, so leaving it visible is recommended.

Why hiding doesn't work

  • The SSID is only removed from beacon frames; it is still included in plaintext in the probe/association request packets sent by connected devices. Wireless sniffing tools (airodump-ng, etc.) reveal it in a few seconds.
  • What attackers actually want is not the SSID but to crack the encryption key or exploit vulnerabilities, so hiding the name provides no defense.

Drawbacks

  • A device saved to connect to a hidden SSID keeps sending probe requests asking "Is that SSID here?" wherever it goes. In effect, it broadcasts your home SSID even at cafés and airports, which is worse for tracking and privacy. With a normal SSID, the device just quietly listens for beacons, so there is no such problem.
  • There are also side effects such as compatibility problems with some devices, roaming delays, and more cumbersome connection setup.
  • The 802.11 standard itself does not define hiding as a security feature.

What actually helps security

  • Use WPA3 (or WPA2-AES if not available), disable WPS
  • A long, random password (20+ characters)
  • Keep router firmware up to date, turn off remote management
  • Separate IoT devices onto a guest network/separate VLAN
  • Do not put personal information (name, unit number, router model name) in the SSID

Summary

In short, hiding the SSID is "inconvenience, not security", and the key is WPA3 + a strong password + WPS off.

See also

Favorite site

  • Wikipedia (en) Wi-Fi
  • Wi-Fi Alliance
  • Why faster Wi-Fi speeds make quality worse | GeekNews
    • The best experience on the 5 GHz band comes from narrow 20/40 MHz channel widths, but consumer products default to wide channel widths of 80MHz or more, causing more interference and latency
    • Because consumers prefer faster speeds, manufacturers/ISPs stick to wide channels for fear of dropping in benchmark rankings if they ship with narrow channel settings
    • Running a Wi-Fi speed test itself consumes the network's shared bandwidth, degrading responsiveness, and other devices on the network suffer latency and packet loss
    • IEEE's next-generation Wi-Fi 8 (802.11bn) aims to improve reliability and responsiveness rather than speed, but standardization is not expected to be complete until 2028
    • Significant improvements are possible just by changing the settings of currently deployed hardware
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