What is the difference between a Basic Service Set (BSS) and an Extended Service Set (ESS)?

What is the difference between a Basic Service Set (BSS) and an Extended Service Set (ESS)?

• A. A BSS covers multiple APs; an ESS is a single AP.
• B. BSS is a single AP's network; ESS is a set of BSSs interconnected via a distribution system for seamless roaming.
• C. BSS and ESS are identical concepts.
• D. ESS operates at layer 2; BSS operates at layer 3.

Answer: (B)

The idea being tested is how a single AP’s wireless area and a network of APs relate to BSS and ESS. A Basic Service Set is the wireless network that a single access point serves—the AP and all stations connected to it form one BSS. It defines one BSSID for that AP, and devices in this area communicate through that AP. When you have two or more BSSs, each with its own AP and its own BSSID, and you connect them over a distribution system (the wired backbone or a similar link), you create an Extended Service Set. The ESS covers a larger area by linking these BSSs, and devices can roam from one BSS to another within the same ESS while keeping the same network identity (same SSID), thanks to the distribution system coordinating handoffs. So, a BSS is a single AP plus its clients; an ESS is a collection of interconnected BSSs that lets devices roam across APs within the same network.

The idea being tested is how a single AP’s wireless area and a network of APs relate to BSS and ESS. A Basic Service Set is the wireless network that a single access point serves—the AP and all stations connected to it form one BSS. It defines one BSSID for that AP, and devices in this area communicate through that AP.

When you have two or more BSSs, each with its own AP and its own BSSID, and you connect them over a distribution system (the wired backbone or a similar link), you create an Extended Service Set. The ESS covers a larger area by linking these BSSs, and devices can roam from one BSS to another within the same ESS while keeping the same network identity (same SSID), thanks to the distribution system coordinating handoffs.

So, a BSS is a single AP plus its clients; an ESS is a collection of interconnected BSSs that lets devices roam across APs within the same network.