3com 3CRWE52196 Betriebsanweisung

Seite von 120
78
C
HAPTER
 6: T
ROUBLESHOOTING
Ensure that the Wireless Clients are using the same SSID or Service 
Area Name as the Gateway. The SSID is case-sensitive
Ensure that you are using the same level of security on all of your 
wireless computers (None, 40/64 or 128 bit) and that all devices are 
using the same keys, and the same order of keys where appropriate.
Ensure that you have the Wireless computer enabled in the list of 
allowed MAC addresses if you are using Wireless Connection control 
on the Gateway. 
If you are having difficulty connecting or are operating at a low speed 
try changing the antenna positions on the rear of the Gateway. For 
more effective coverage you can try reorientating your antennae. 
Place one antenna vertically and one horizontally to improve coverage. 
Additionally consider moving the wireless computer closer to the 
Gateway to confirm that the building structure or fittings are not 
adversely affecting the connectivity. If this resolves the problem 
consider relocating the Wireless computer or the Gateway, or trying a 
different channel on the Gateway.
Sources of interference: The 2.4Ghz ISM band is used for 802.11b. 
This is generally a licence free band for low power applications, and 
you may have other devices at your location that operate in this 
frequency band. You should take care to ensure that there are no 
devices like microwave ovens for example close to the Gateway or 
wireless computers as this could affect receiver sensitivity and reduce 
the performance of your network. If you are unsure try relocating both 
the wireless computers and the Gateway to establish whether this 
problem exists.
Most wireless computer Adapters will scan the channels for the 
wireless Gateway. If a wireless computer has not located the Gateway 
then try initiating a search manually if the client software supports this 
feature or manually set the channel on your wireless computer to 
correspond to the Gateway channel number. Please refer to your 
Wireless computer adapter documentation and vendor to do this.
Speed of connection: The 802.11b standard will automatically choose 
the best speed depending on the quality of your connection. As the 
signal quality weakens then the speed falls back to a lower speed. The 
speeds are 11Mbps, 5.5Mbps, 2Mbps and 1Mbps. In general the 
closer you are to the Gateway the better the speed. If you are not 
achieving the speed you had anticipated then try moving the antenna 
on the Gateway or moving the Wireless computer closer to the 
Gateway. In an ideal network the Gateway should be located in the