OTC Wireless WiSER2400 - Manual (Page 18)

Poor Link Quality
If the Signal Strength indicator is reasonably high (>20%) and the Link Quality is
not zero, but the “Link Quality” stays in the Poor range, it could be due to one of
the following reasons:
• Make sure that radio interference is not present in the radio network.
• Make sure that the radio is not surrounded by many strongly reflecting
(metallic) surfaces. With multiple reflecting surfaces between the radio in
question and the target radio, a severe
multi-path problem may introduce
high bit error rate despite a strong Signal Strength.
• Make sure that there no severe packet collision caused by a “hidden
node” problem. A “hidden node” problem is the situation where the RF
signal from two or more Station radios cannot reach each other (but can
reach the AP). In such situation, multiple Stations may attempt to transmit
data packet to the AP at the same time and therefore cause packet
collision. To solve this problem, either re-arrange the Stations in question
such that the RF signals are mutually sensible by all Stations, or turn-on
the RTS/CTS protocol by setting the “
RTS threshold ” on the “Station” sub-
tab to a reasonably small value (500, for example). There is no guarantee
that the packet collision can be entirely eliminated by invoking RTS/CTS
protocol, but the severity can be reduced enough to see visible
improvement of the link quality.
Radio Interference
You may be able to minimize RF interference by doing the following:
• Although WiSER2400, when properly configured, seeks a clear channel to
use, it cannot avoid interference if too many 2.4GHz interference sources
are present. A “clear” channel should be at least 20MHz, but preferably
30MHz, apart from any other channel in use. Find out other usages in this
frequency band in the vicinity and try to coordinate the channel
assignment with other users.
• Reseat the WiSER2400 radio to a location where the interference is
minimized; in general, increasing the distance between the radio pair may
cause radio interference.
• Avoid using 2.4GHz cordless phone in the vicinity of the radios
• Keep the computer with the WiSER2400 radio away from the microwave
oven and large metal objects.
• Consult the dealer or an experienced radio technician for help and
assistance.
15