Why there are four addresses in ESS frame header?

Answer 1

In an IEEE 802.11 ESS (Extended Service Set) frame header, there are four addresses to facilitate communication across multiple access points in a wireless network. These addresses include the source address (STA), destination address (STA), BSSID (Basic Service Set Identifier), and the transmitter address. This structure allows for proper routing of frames between different stations and access points, enabling efficient communication and ensuring that data is directed correctly within the extended service set. The use of four addresses helps manage the complexities of wireless networking, especially in environments with multiple devices and access points.