2. WLAN (Wireless Local Area Network)

The IEEE 802.11 standard describes the characteristics of a wireless local area network (WLAN). The name Wi-Fi (Wireless Fidelity) originally came from the name given to the certification issued by the Wi-Fi Alliance, which is responsible for maintaining interoperability between 802.11-compliant equipment.

The IEEE 802.11 standard offers two modes of operation: an infrastructure mode and an ad hoc mode. In ad hoc mode, two wireless stations can communicate directly with each other when they are physically within the same propagation radius (see section ). In contrast, in infrastructure mode, the basic entity of a wireless network is the cell controlled by an access point. The access point is generally equipped with two network interfaces:

• a wireless interface through which it receives all the frames...