Fujitsu Siemens Computers STYLISTIC ST41 Series, User Manual

Page: 41 / 71

A26391-K129-Z121-1-7619
English - 35
Wireless LAN
Your Tablet PC can be upgraded with an integrated wireless LAN module (PRISM Wireless LAN) as
an option. The
PRISM Configuration Utility
is provided for configuration and status displays of the
network card.
This chapter describes how to install the drivers and the configuration utility and how to make
settings for your wireless LAN.
Wireless network as per IEEE 802.11 standard
The "PRISM Wireless LAN" network card operates in accordance with the IEEE 802.11 standard.
The 2.4 GHz ISM frequency band is used as a communications medium. The wireless networks
operating in accordance with 802.11 can easily be connected to existing Ethernet networks. With
the exception of a few additional parameters, wireless network cards that operate in accordance
with 802.11 are one system with a normal Ethernet card. This means that you can use all protocols
via a 802.11 wireless network just as with a cable-connected Ethernet (IP, IPX, NetBIOS,...). The
only difference is that you need not lay cables between the computers. The number of all wireless
LAN stations that can reach each other directly is generally referred to as a cell. The IEEE standard
offers two operating modes - the adhoc mode (peer-to-peer) and the infrastructure mode.
Adhoc mode
A wireless LAN in the adhoc mode, also called peer-to-peer mode, consists of a single closed cell.
Adhoc wireless networks result when a workgroup comes together with its systems and would like to
interconnect these for data exchange. Any number of systems can be added to this type of network
and can leave it again.
So that several adhoc wireless networks do not interfere with each other in radio traffic, there is a
unique network name, the SSID (Service Set Identifier). The SSID is used for addressing so that a
data packet can always be assigned to a certain cell.
If you want to join an existing cell, you require the network name (SSID), which you enter in the
settings for the network card. The driver searches for a wireless network with this ID during start-up.
When the driver has found a wireless network, it connects to it and you can communicate with the
systems in this wireless network. If two cells are very close together, the channels of these networks
should be 4 to 5 channels apart.
Infrastructure mode
In the infrastructure mode, a base station, referred to as an AccessPoint, exists in addition to the
mobile stations. In the infrastructure mode the AccessPoint assumes the function of a "guard". In
contrast to the adhoc mode, each system must log on to the AccessPoint before it is allowed to
exchange data in the cell.
Another task of the AccessPoint is the connection of the cells with a cable-connected Ethernet. As
due to the logon requirement, the AccessPoint knows at all times exactly which stations are on the
radio side, it can decide exactly which data must be sent to it and which don't. This process is also
referred to as bridging.