802.11 Protocol Architecture
Between stations in the BSS (for communication within the
BSS)
Between stations in the BSS and the portal (for communication
with devices outside the ESS)
Figures 2.1 illustrates Intra-BSS Communication.
FIGURE 2.1
Intra-BSS Communication
An ESS that consists of multiple BSSs has a more complex DS. The
DS is in each access point and in the wired or wireless DS medium
(DSM) across which the access points distribute messages to each
other. The
DS medium is sometimes incorrectly equated to the DS itself.
If the DS medium is Ethernet, then access points transport messages to
each other using their portals and Ethernet ports (called the Integrated
LAN). While the messages distributed between access points actually
leave the ESS while traversing the integrated LAN, abstractly the
