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Wi-Fi (Wireless Fidelity - IEEE 802.11)

Wi-Fi is a wireless networking technology that allows devices to connect to a local area network (LAN) without physical cables. It is based on IEEE 802.11 standards and is commonly used in homes, businesses, and public spaces.

1. Wi-Fi Standards and Speeds

Wi-Fi has evolved through multiple generations, each improving speed, range, and efficiency.

Standard Frequency Max Speed Range (Indoor) Common Use
802.11a 5 GHz 54 Mbps ~35m Early enterprise Wi-Fi
802.11b 2.4 GHz 11 Mbps ~35m Early consumer Wi-Fi
802.11g 2.4 GHz 54 Mbps ~38m Home & small offices
802.11n (Wi-Fi 4) 2.4 & 5 GHz 600 Mbps ~70m First MIMO-based Wi-Fi
802.11ac (Wi-Fi 5) 5 GHz 6.9 Gbps ~35m Modern home & business Wi-Fi
802.11ax (Wi-Fi 6) 2.4 & 5 GHz 9.6 Gbps ~40m High-density areas, IoT
802.11be (Wi-Fi 7) 2.4, 5 & 6 GHz 40+ Gbps ~40m Future ultra-high-speed networks

Wi-Fi 6E and Wi-Fi 7 introduce the 6 GHz band, reducing congestion and increasing speeds.

2. Frequency Bands

Wi-Fi operates on different frequency bands, each with trade-offs in speed and range.

  • 2.4 GHz:
  • Pros: Longer range, better penetration through walls.

  • Cons: Slower speeds, more interference (due to Bluetooth, microwaves, etc.).

  • 5 GHz:

  • Pros: Faster speeds, less interference.

  • Cons: Shorter range, struggles with obstacles.

  • 6 GHz (Wi-Fi 6E & Wi-Fi 7):

  • Pros: High speed, low latency, minimal interference.
  • Cons: Shortest range, requires compatible hardware.

3. Wi-Fi Network Components

  • Access Point (AP): Broadcasts Wi-Fi signals for devices to connect.
  • Router: Connects the Wi-Fi network to the internet.
  • Mesh Systems: Multiple nodes that extend coverage seamlessly.
  • Client Devices: Laptops, smartphones, IoT devices that use Wi-Fi.

4. Wi-Fi Security Protocols

Protocol Encryption Security Level Status
WEP (Wired Equivalent Privacy) RC4 Weak Obsolete
WPA (Wi-Fi Protected Access) TKIP Moderate Deprecated
WPA2 AES Strong Widely used
WPA3 AES-CCMP, SAE Strongest Latest standard

WPA3 enhances security with Simultaneous Authentication of Equals (SAE), preventing brute-force attacks.

5. Wi-Fi Connection Methods

  • Infrastructure Mode: Devices connect via an access point (most common).
  • Ad-Hoc Mode: Devices connect directly to each other (P2P).
  • Wi-Fi Direct: Direct device-to-device communication without a router.
  • Hotspots: Public Wi-Fi access points in cafes, airports, etc.

6. Wi-Fi Performance Factors

  • Interference: From other Wi-Fi networks, Bluetooth, microwaves.
  • Obstacles: Walls, furniture, and metal objects weaken signals.
  • Bandwidth Sharing: Multiple devices can slow down the network.
  • Channel Selection: Overlapping channels (e.g., in 2.4 GHz) cause congestion.

7. Wi-Fi vs. Ethernet

Factor Wi-Fi Ethernet
Speed Slower (max ~10 Gbps) Faster (up to 100 Gbps)
Latency Higher Lower
Stability Prone to interference More reliable
Mobility High Limited to cable length
Security Requires encryption More secure (physical access needed)

Wi-Fi is best for mobility and convenience, while Ethernet excels in speed and reliability.