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Manual Datafox ZK-MasterIV
3.5.8 WLAN
3.5.8.1 General information
There are two possibilities to configure the match port. Either via the TCP/IP with the DeviceInstaller TM
of Lantronix
R
or via the RS232 using the tool WLANConfig and the DatafoxStudio (from version
04.01.06.xx on).
3.5.8.2 Terms and explanations
3.5.8.2.1 Infrastructure Mode
(Loose translation of an excerpt from the German version Wikipedia, the free encyclopaedia)
The Infrastructure mode is similar to the structure of the mobile communications network: A special base
station (Access Point) is used to coordinate the other network nodes (Clients). The base station sends
small data packets (so called Beacons) in adjustable intervals (ten times per second by default) to all
stations being in the footprint. The beacons contain among others the following information: Network
name ("Service Set identifier", SSID), List of supported transfer rates, Type of encryption.
This beacons ease the connection establishment, because the clients just have to know the network name
and optional some parameters for the encryption. The permanent sending of beacon-packets also allows
a control of the reception quality - also when no user data are sent or received. The beacons are always
sent with the lowest transfer rate (1 MBit/s), the successful reception of the beacons does not guarantee
a steady connection to the network.
3.5.8.2.2 Ad-hoc Mode
(Loose translation of an excerpt from the German version Wikipedia, the free encyclopaedia)
In the Ad-hoc mode (lat.: "created for this moment") no station is favoured; they all are on a par. Ad-hoc
networks can be established quickly and without great effort. But for a spontaneous networking of a few
terminals other techniques (Bluetooth, Infrared) are commonly used.
The preconditions for using the Ad-hoc mode are the same as for the Infrastructure mode: All stations
use the same network name ("Service Set Identifier", SSID) and optionally also the same settings for the
encryption. Because there is no central instance for this operating mode and because no beacon-packets
are sent, a client cannot determine, whether there are other stations (using the same settings) within
reach, who is part of the network or how good the connection quality is. Therefore, the Ad-hoc mode is
suitable only for a small number of stations, that have to be close to each other because of the limited
reach of the transmitter. Otherwise, it is possible, that a station cannot communicate with the other
stations, because they simply do not receive a signal.
Forwarding data packets between the stations is not intended and not possible without further ado in
practice, because in the Ad-hoc mode no information are exchanged, that might give the single stations
an overview over the network. Gathering and exchanging these information is part of the upgrading of an
Ad-hoc network to a mobile Ad-hoc network: Software components on each stations collect data (e.g. for
visibility of other stations, connection quality etc.), exchange them among each other and make decisions
concerning the forwarding of the user data. The development in this field is not finished yet. By now
Version: 04.01.07.00 Page
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