Wireless Networking Using 802.11b
Roaming
More than one WAP can be used to increase the wireless coverage in a wireless LAN. The diagram below shows two WAPs configured to extend coverage beyond that of a single WAP. The overlapping area of each BSS is called an Extended Service Set (ESS). When a wireless computer enters the ESS, the signal strength and link quality is evaluated by the computer and the computer chooses the WAP with the best quality signal and link. This activity is known as roaming. To configure WAPs to allow roaming inside of the wireless network, each WAP will be assigned the same Service Set Identifier (SSID). Strategically placing multiple WAPs around an office or inside of the home can extend the wireless coverage to the entire premise. The illustration below shows two Basic Service Sets overlapping to form an Extended Service Set.
Desktop PC
Desktop PC | Switch |
BSS2
Wireless
Access Point
ESS
Wireless
Access Point BSS1
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