A basic service area (BSA), or cell, is the area around an access point where clients can successfully communicate with it. In a basic service set, clients send frames through the AP rather than directly to one another. section 18.3.2 section 18.5
Keep these wireless LAN relationships distinct:
- A BSS identifies the wireless network served by an AP; its SSID is user-facing, while its BSSID uniquely identifies the BSS, usually through the AP radio’s MAC address. section 18.3.2
- One AP can provide multiple BSSs, but a single-radio AP places them on the same channel, so they do not reduce channel congestion. section 18.3.2
- An ESS links multiple BSSs through a distribution system, expanding coverage; overlapping cells support roaming between APs. section 18.5
Figure 18.14 A BSS consisting of an AP and three clients. Clients cannot send frames directly to each other; they must communicate via the AP.
Use the topology figure to see why clients in one BSS communicate through the AP instead of sending frames directly. section 18.3.2
