Wireless Network Modes

The simplest wireless network consists of two or more PCs communicating directly with each other without cabling or any other intermediary hardware. More complicated wireless networks use an access point to centralize wireless communication, and to bridge wireless network segments to wired network segments. These two different methods, or modes, are called ad hoc mode and infrastructure mode.

Ad Hoc Mode Ad hoc mode is sometimes called peer-to-peer mode, with each wireless node in direct contact with each other node in a decentralized free-for-all. Ad hoc mode does not use an access point and instead uses a mesh topology.

Two or more wireless nodes communicating in ad hoc mode form what's called an Independent Basic Service Set (IBSS). This is a basic unit of organization in wireless networks. Think of an IBSS as a wireless workgroup and you're not far off the mark.

Ad hoc mode networks work well for small groups of computers (fewer than a dozen or so) that need to transfer files or share printers. Ad hoc networks are also good for temporary networks, such as study groups or business meetings.

Hardly anyone uses ad hoc networks for day-to-day work, simply because you can't use an ad hoc network to connect to other networks unless one of the machines is running Internet Connection Sharing (ICS) or some equivalent. More commonly, you'll find wireless networks configured in infrastructure mode.

NOTE Infrastructure mode is so much more commonly used than ad hoc mode that most wireless NICs come preconfigured to run on an infrastructure mode network. Getting them to run in ad hoc mode usually requires reconfiguration.