WiFi: IEEE 802.11 Wireless LAN

This chapter discusses the technology evolution of IEEE 802.11, more popularly known as WiFi. It describes the MAC layer and the physical layer, which have some unique features when compared to cellular systems. The MAC layer consists of two major functional entities: the MAC sublayer and the MAC layer management entity (MLME). The core functions of channel access, retransmissions, packet fragmentation and encryption are handled by the MAC sublayer. The MLME handles higher MAC functions such as synchronization, power management, and connection management, which include association and authentication. The chapter talks about some of these functions. It explains in detail the physical‐layer enhancements, as well as MAC enhancements. The widespread proliferation of WiFi networks has given rise to an entire industry catering to the design, control, operation, and management of networks with tens to hundreds of access points (APs).