Lesson 48: Basic Wireless LAN Concepts

Wireless Local Area Networks (WLANs) use radio frequency (RF) to connect devices based on the IEEE 802.11 standards (Wi-Fi).

Key Components

1. STA (Station): The client device (laptop, phone).
2. AP (Access Point): Connects wireless devices to the wired LAN infrastructure.
3. WLC (Wireless LAN Controller): In enterprise environments, WLCs manage hundreds or thousands of APs centrally.

WLAN Operation

• SSID (Service Set Identifier): The name of the Wi-Fi network (e.g., 'GuestNet').
• Channel: The specific frequency band used for transmission (2.4 GHz or 5 GHz).
• CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance): Unlike wired Ethernet (CSMA/CD), wireless uses collision avoidance because devices cannot easily detect collisions.

Authentication and Security

• WPA2/WPA3 (Enterprise): Uses 802.1X and RADIUS servers for stronger security, requiring unique credentials for each user.
• WPA2/WPA3 (Personal/PSK): Uses a shared passphrase.