SMC Networks EliteConnect SMC2555W-AG User Manual page 47

A wireless infrastructure can also support roaming for mobile
workers. More than one access point can be configured to create
an Extended Service Set (ESS). By placing the access points so
that a continuous coverage area is created, wireless users within
this ESS can roam freely. All SMC wireless network card
adapters and SMC2555W-AG wireless access points within a
specific ESS must be configured with the same SSID.
Desktop PC
Switch
Access Point
PC with Wireless
PCI Adapter
File
Server
Switch
Access Point
Notebook with Wireless
PC Card Adapter
<ESS>
<BSS1>
Seamless Roaming
Network Topologies
Notebook with Wireless
PC Card Adapter
<BSS2>
3-5