ESS
Mobile wireless clients can roam around within the same network if you set all your access
points to the same SSID. Doing this creates an ESS. Figure 9.6 shows four APs configured with
the same SSID in an office thereby creating the ESS network.
For users to be able to roam throughout the wireless network—from AP to AP without losing
their connection to the network—all APs must overlap by at least 10 percent or more, and the
channels on each AP shouldn’t be set the same either. And remember, in an 802.11b/g network,
there are only three nonoverlapping channels (1, 6, 11), so design is really important here!