8.5.Types of WLANs

• WLANs can be categorized based on their use of wireless APs.

• The three main categories are

  1. independent basic service set (IBSS)

  2. basic service set (BSS)

  3. extended service set (ESS)

1.IBSS

• As shown in Figure , a WLAN can be created without the use of an AP. Such a configuration, called an IBSS, is said to work in an ad hoc fashion.

• An ad hoc WLAN is useful for temporary connections between wireless devices.

  • For example, you might temporarily interconnect two laptop computers to transfer a few files.

2.BSS

• WLANs that have just one AP are called BSS WLANs.

• BSS WLANs are said to run in infrastructure mode because wireless clients connect to an AP, which is typically connected to a wired network infrastructure.

• A BSS network is often used in residential and SOHO locations,

  where the signal strength provided by a single AP is sufficient to service all the

  WLAN’s wireless clients.

ESS

• WLANs containing more than one AP are called ESS WLANs .

• Like BSS WLANs, ESS WLANs operate in infrastructure mode.

• When you have more than one AP, take care to prevent one AP from interfering with another.