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WiFi (Wide fidelity) fundamentals/Basics





Wi-Fi stands for wireless Fidelity. WiFi is based on the IEEE 802.11 family of standards. Wi-Fi uses (RF)electromagnetic signal to transmit and receive data. Frequency band 2.4, 3.6, 5, and 60 GHz
Why Wi-Fi is half Duplex?
All Wi-Fi networks are contention-based TDD systems, where the access point and the mobile stations use the same channel. Because of the shared media operation, all Wi-Fi networks are half duplex.

How does wifi client connects to Wifi access point:

 it is important to understand how an Access Point and wireless client start their initial communication. Once the wireless network is up and running, WLAN clients connect to an Access Point that provides it the best connection and data rate possible. Before a client connects to an AP, the client must first figure out to which AP it should connect. 802.11 WLANs consist of multiple elements and behaviors which make up the foundation of the 802.11 protocol. A key part of the protocol discovers the appropriate WLAN and establishes a connection with that WLAN. The primary components of this process are: 
• Beacons—Used by the WLAN network to advertise its presence. 
• Probes—Used by WLAN clients to find their networks. 
• Authentication—An artifact from the original 802.11 standard. 
• Association—Establishes the data link between an AP and a WLAN client.



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