MRV Communications MRW55, User Manual

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Access Point Topologies
2-3
2
Infrastructure Wireless LAN for Roaming Wireless PCs
The Basic Service Set (BSS) defines the communications domain for each access
point and its associated wireless clients. The BSS ID is a 48-bit binary number
based on the access point’s wireless MAC address, and is set automatically and
transparently as clients associate with the access point. The BSS ID is used in
frames sent between the access point and its clients to identify traffic in the service
area.
The BSS ID is only set by the access point, never by its clients. The clients only
need to set the Service Set Identifier (SSID) that identifies the service set provided
by one or more access points. The SSID can be manually configured by the clients,
can be detected in an access point’s beacon, or can be obtained by querying for the
identity of the nearest access point. For clients that do not need to roam, set the
SSID for the wireless card to that used by the access point to which you want to
connect.
A wireless infrastructure can also support roaming for mobile workers. More than
one access point can be configured to create an Extended Service Set (ESS). By
placing the access points so that a continuous coverage area is created, wireless
users within this ESS can roam freely. All wireless network card adapters and
wireless access points within a specific ESS must be configured with the same
SSID.
Server
Switch
Desktop PC
Access Point
<BSS2>
Seamless Roaming
for Wireless Clients
<ESS>
Switch
Access Point
<BSS1>
PC with Wireless
PCI Adapter
Notebook with Wireless
PC Card Adapter
Notebook with Wireless
PC Card Adapter