Cabletron Systems RoamAbout Access Point Manual page 18

Wireless Infrastructure Network
Multiple Access Points
A wireless infrastructure network can consist of multiple Access Points. This extends the
coverage area of the wireless network. To allow roaming, each Access Point in the wireless
network must use the same Wireless Network Name.
In this configuration, the wireless network consists of cells. A cell is a single Access Point
and its wireless clients within a network of multiple Access Points.
Figure 1-1 shows two Access Points in the same wireless network.
Figure 1-1: Cells Within a Wireless Infrastructure Network Configuration
To allow wireless clients to physically move within a wireless network, the coverage areas
should overlap. In Figure 1-1, Cell 1 and Cell 2 share overlapping areas of coverage. As a
wireless client moves from Cell 2 to Cell 1, the necessary infrastructure network
information is passed from AP1 to AP2 while maintaining LAN connectivity. The
capability of moving from one Access Point to another without losing the network
connection is called roaming.
When a wireless client (such as the laptop computer in Figure 1-1) approaches the outside
boundary of a coverage area, the client can sense that another Access Point using the same
Wireless Network Name is providing a better quality signal. The client then automatically
switches to the other Access Point. If the other Access Point is using a different channel,
the client automatically switches to that channel.
1-6 Wireless Network Configurations