IEEE 802.11 defines two operating modes:

• Ad hoc mode and
• Infrastructure mode.

In ad hoc mode, also known as peer-to-peer mode, wireless clients communicate directly with each other (without the use of a wireless AP). Two or more wireless clients who communicate using ad hoc mode form an Independent Basic Service Set (IBSS). Ad hoc mode is used to connect wireless clients when a wireless AP is not present.

In infrastructure mode, there is at least one wireless AP and one wireless client. The wireless client uses the wireless AP to access the resources of a wired network. The wired network can be an organisation intranet or the Internet, depending on the placement of the wireless AP.