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wlan tutorial

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A Wireless Local Area Network (WLAN) is a type of local area network that uses wireless communication to connect devices within a limited geographical area, such as a home, office, or campus. WLAN, including its architecture, protocols, security mechanisms, and configuration.

1. WLAN Architecture:

  • Access Points (APs): Access points act as the central communication hub for wireless clients. They facilitate communication between wireless devices and can be standalone devices or integrated into routers.
  • Wireless Clients: Devices like laptops, smartphones, tablets, and IoT devices that connect to the WLAN.

2. Wireless Standards and Protocols:

  • 802.11 Standards: The IEEE 802.11 family of standards defines the specifications for WLANs.
  • Common Standards:
    • 802.11a/b/g/n/ac/ax: Different versions with varying data rates and frequency bands.
  • Wi-Fi Alliance: Ensures interoperability between different vendors' devices through certification programs.

3. Frequency Bands:

  • WLANs operate in the 2.4 GHz and 5 GHz bands.
  • 2.4 GHz: Better range but more susceptible to interference.
  • 5 GHz: Higher data rates and less interference but shorter range.

4. Wireless Security:

  • WEP (Wired Equivalent Privacy): Weak and easily crackable. Obsolete and not recommended.
  • WPA (Wi-Fi Protected Access): Improved security with TKIP (Temporal Key Integrity Protocol).
  • WPA2: Enhanced security with AES (Advanced Encryption Standard).
  • WPA3: Latest security standard, offering stronger encryption and protection against attacks.

5. Authentication and Key Management:

  • Open System Authentication: No authentication (not recommended for security).
  • Shared Key Authentication: Basic challenge-response mechanism.
  • WPA/WPA2-PSK (Pre-Shared Key): Uses a pre-shared passphrase for authentication.
  • 802.1X/EAP: Enterprise-level authentication using a RADIUS server.

6. Wireless Configuration:

  • SSID (Service Set Identifier): Network name broadcasted by APs.
  • BSSID (Basic Service Set Identifier): MAC address of the AP.
  • Channel Allocation: Avoid interference by selecting non-overlapping channels.
  • Wireless Modes: Infrastructure (AP-based) or ad-hoc (device-to-device).

7. Roaming:

  • Seamless Roaming: The ability of a device to maintain a connection while moving between APs.
  • Fast BSS Transition (FT): Speeds up the roaming process.

8. Quality of Service (QoS):

  • Prioritizes certain types of traffic for better performance.
  • Helps in delivering a consistent level of service for time-sensitive applications like voice and video.

9. Wireless Site Survey:

  • Conducted to analyze the RF (Radio Frequency) environment.
  • Helps optimize AP placement and channel selection for optimal performance.

10. Emerging Technologies:

  • Wi-Fi 6 (802.11ax): Improves efficiency, capacity, and performance in crowded environments.
  • 6 GHz Band (802.11ay): Additional spectrum for increased bandwidth.