Siemens CP 1515 - Manual (Page 130)

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130 Industrial Ethernet Wireless LAN RLM Manager, CP 1515 Manager
C79000-G8976-C171-01
• When the number of
2XW HUURUV
is 1% or more of the
%ULGJH RXW
SDFNHWV
, it is likely that one or more stations suffer form a poor link
quality.
3. Compare the number of packets
2XW FROOLVLRQV
with the number of
%ULGJH RXW SDFNHWV
.
• If the number of
2XW FROOLVLRQV
is 1% or more of the
%ULGJH RXW
SDFNHWV
, it is likely that the wireless medium is very busy. This
might be caused by many retransmitted frames, but it could also
refer to many stations trying to communicate at the same time.
4. You can also use the RLM Manager remote link test to analyze whether
one or more stations show a poor link quality:
• When the poor link quality is caused by a low signal level, the
station is almost out of range of the Access Point RLM.
• When the poor link quality is caused by a high noise level, there is a
source of interference in the signal path between the station and
the Radio Link Module.
5. When one or more stations show a poor link quality, re-transmissions of
frames will disturb overall statistics and performance.
• You may be able to solve the problem by either moving the
station(s) or eliminating the source of interference.
• If the problem is a poor signal you may consider:
— Connecting a range extending antenna to the station or access point
that suffers from poor radio performance.
— Adding an extra Access Point RLM to the network, or
— Adjusting the placement of your Access Points RLMs to provide
coverage for all wireless stations.