Date Added: Apr 2010
The majority of Wireless Local Area Network (WLAN) technologies, including the Wireless Fidelity (WiFi) standard IEEE 802.11, is characterized by the use of a single shared channel. The use of a single channel is very different from most wireless cellular technologies [for example, Global System for Mobile communications (GSM)], where communications simultaneously occur in independent wireless channels deployed in different time slots and frequency bands. Indeed, the use of a shared channel necessitates the specification of some access rules to guarantee that terminals transmit in different time intervals without collision. These rules are defined in the Medium Access Control (MAC) layer, which represents a fundamental part of every WLAN standard.