ZyXEL Communications Wireless Access Point ZyAIR B-500 User Manual page 185

ZyAIR B-500 Wireless Access Point User's Guide
The Extended Service Set (ESS) shown in the next figure consists of a series of overlapping BSSs (each
containing an Access Point) connected together by means of a Distribution System (DS). Although the DS
could be any type of network, it is almost invariably an Ethernet LAN. Mobile nodes can roam between
access points and seamless campus-wide coverage is possible.
Diagram D-2 ESS Provides Campus-Wide Coverage
Wireless LAN and IEEE 802.11 D-3