Infrastructure Mode

Wireless networks running in infrastructure mode use one or more WAPs to connect the wireless network nodes centrally. This configuration is similar to the star topology of a wired network. You also use infrastructure mode to connect wireless network segments to wired segments. If you plan to set up a wireless network for a large number of PCs, or you need to have centralized control over the wireless network, infrastructure mode is what you need.

A single WAP servicing a given area is called a Basic Service Set (BSS). This service area can be extended by adding more access points. This is called, appropriately, an Extended Service Set (ESS).

NOTE A lot of techs have dropped the word "basic" from the Extended Basic Service Set, the early name for an infrastructure-mode wireless network with more than one WAP. Accordingly, you'll see the initials for the Extended Basic Service Set as ESS. Using either EBSS or ESS is correct.

Wireless networks running in infrastructure mode require a little more planning- such as where you place the WAPs to provide adequate coverage-than ad hoc mode networks, and they provide a stable environment for permanent wireless network installations. Infrastructure mode is better suited to business networks, or networks that need to share dedicated resources such as Internet connections and centralized databases. (See "Implementing Wi-Fi" later in this tutorial.)