Wireless Room Sensor Solution
Table 9 lists RSX parameters used to determine link quality.
Table 9. COMM RSX Parameters.
Parameter
Indicates
Good Quality if
value is:
To improve quality:
Mac % Acked
Percentage of RSX messages
successfully received and
acknowledged by the WRS
radio.
Between 90% — 100%
Wait for automatic
channel change in case
of interference. If no
improvement, reposition
one device to bring
closer or provide better
line-of-sight to the other
device.
Mac % Backoffs
Percentage of RSX messages
that were delayed (backed
off) because the radio channel
was busy (typically because of
interference).
Less than 10%
Wait for automatic
channel change to
resolve interference.
Dest Avg RSSI (dBm)
Average signal strength in dBm
of messages received from the
WRS.
Greater than –80dBm
(such as –75dBm)
Reposition one device to
bring closer or provide
better line-of-sight to the
other device.
Dest Avg Correlation
Average signal correlation of
messages received from the
WRS. A value of about 110
indicates a maximum quality
frame, while a value of 50 is the
lowest quality frame detectable
by the RSX.
90 or greater
Wait for automatic
channel change in case
of interference. If no
improvement, reposition
one device to bring
closer or provide better
line-of-sight to the other
device.
Avg Channel RSSI
(dBm)
Average signal strength in dBm
of the current channel. Since
the RSX has its receiver turned
on at all times, it samples
the RSSI periodically on the
channel to determine how noisy
the channel is.
–80dBm or less (such as
–85dBm)
Wait for automatic
channel change to
resolve interference.
Revision Date: July 10, 2008
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Siemens Building Technologies, Inc.
