MAC Layer

The Medium Access Control (MAC) header encapsulates an Logical Link Control (LLC) frame whose size is less than or equal to 2,304 bytes. The basic service set identifier (BSSID) field contains the MAC address of the access point and the transmitter address (TA) field of the station. The transmission of several frames is separated by an inter‐frame interval. The security of the radio interface started with the Wired Equivalent Privacy (WEP) mechanism. The three mechanisms WEP, (Wi‐Fi Protected Access) WPA1 and WPA2 specifically implement third‐party access control and data protection services. The security policies supported by the access point are transmitted in BEACON and PROBE RESPONSE frames during the scanning phase. The MAC header of the traffic frame inserts the two‐byte Quality of Service (QoS) Control field following the Address 4 field.