• Current and older Wifi standards
  • 802.11a
  • 802.11b
  • 802.11g
  • 802.11n
• Wifi 6
• Wifi Components
  • wireless access point (AP)
  • Wireless routers
  • Mobile Hotspot
• Wifi performance
  • Transmitter power
  • Antenna
• Wifi Security
  • WEP (Wired Equivalent Privacy) 
  • WiFi Protected Access version 2 (WPA2) 
  • WiFi Protected Setup (WPS) 
  • WPA3  
  • WPA3-Enterprise

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Wi‑Fi is a trademark of the Wi-Fi Alliance. It belongs to the family of radio technologies commonly used for wireless local area networking (WLAN) devices.

Current and older Wifi standards

Standards operate on varying frequencies, deliver different bandwidths, and support different numbers of channels.

802.11a

Transmits at 5 GHz frequency band of the radio spectrum with 54 megabits of data per second.

Orthogonal frequency-division multiplexing (OFDM) splits radio signals into several sub-signals before they reach a receiver to reduce interference.

802.11b

Transmits at 2.4 GHz with a speed of 11 megabits of data per second

Complementary code keying (CCK) modulation to improve speeds

802.11g

Transmits at 2.4 GHz but faster up to 54 megabits of data per second. It uses OFDM coding.

802.11n

Speeds 140 megabits per seconds. Backward compatible with a, b and g. 

Transmit up to 4 streams of data, each at a maximum of 150 megabits per second, but most routers only allow for 2 or 3 streams.

Backward compatible with 802.11n and thus others. 450 megabits per second on a single stream. It is also called 5G WiFi because of its frequency band .

(+) Very High Throughput (VHT)

Wifi 6

Wi-Fi CERTIFIED 6 networks enable lower battery consumption in devices, making it a solid choice for any environment, including smart home and Internet of Things (IoT) uses.

Wifi Components

• wireless access point (AP) allows wireless devices to connect to the wireless network.
  takes the bandwidth coming from a router and stretches it so that many devices can go on the network from farther distances away. Gives useful data about the devices on the network, provide proactive security, and serve many other practical purposes.
• Wireless routers are hardware devices that Internet service providers use to connect you to their cable or xDSL Internet network.
  combines the networking functions of a wireless access point and a router.
• Mobile hotspot – feature on smartphones with both tethered and untethered connections
  share your wireless network connection with other devices

Wifi performance

Wi-Fi operational range depends on factors such as the frequency band, radio power output, receiver sensitivity, antenna gain and antenna type as well as the modulation techniquea and propagation charestristics of the signal

Transmitter power
Compared to cell phones and similar technology, Wi-Fi transmitters are low power devices. In general, the maximum amount of power that a Wi-Fi device can transmit is limited by local regulations, such as FCC Part 15 in the US. Equivalent isotropically radiated power (EIRP) in the European Union is limited to 20 dBm (100 mW).

Antenna
An access point compliant with either 802.11b or 802.11g, using the stock omnidirectional antenna might have a range of 100 m.

Wifi Security

WEP (Wired Equivalent Privacy) 

The client connects to a WEP-protected network, the WEP key is added to some data to create an “initialization vector” IV

WiFi Protected Access version 2 (WPA2) 

Successor to WEP and WPA. It uses either TKIP or Advanced Encryption Standard (AES) encryption.

WiFi Protected Setup (WPS) 

WPS ties a hard-coded PIN to the router for setup is vulnerable for exploitation by hackers

WPA3  

WPA3 uses the latest security methods, higher grader security protocols

Disallow outdated legacy protocols

Require use of Protected Management Frames (PMF)

• (+) Increased protection from password guessing attempts
• Better password protection through Simultaneous Authentication of Equals (SAE), which replaces Pre-shared Key (PSK) in WPA2-Personal.

WPA3-Enterprise

192-bit minimum-strength security protocols and cryptographic tools

Authenticated encryption: 256-bit Galois/Counter Mode Protocol (GCMP-256)

Key derivation and confirmation: 384-bit Hashed Message Authentication Mode (HMAC) with Secure Hash Algorithm (HMAC-SHA384)

Key establishment and authentication: Elliptic Curve Diffie-Hellman (ECDH) exchange and Elliptic Curve Digital Signature Algorithm (ECDSA) using a 384-bit elliptic curve

Robust management frame protection: 256-bit Broadcast/Multicast Integrity Protocol Galois Message Authentication Code (BIP-GMAC-256)

References :
[1] wi-fi.org https://www.wi-fi.org/
[2] Wikipedia https://en.wikipedia.org/wiki/Wi-Fi
[3] wi-fi.org https://www.wi-fi.org/discover-wi-fi/wi-fi-certified-6