Polycom KIRK KWS1500 - Manual (Page 16)

KIRK Wireless Server 1500 Installation and Maintenance
RSSI value
The Radio Signal Strength Indicator value is a relative expression for the field strength of
signal from the Base Station. The RSSI value is used for the choice of the alternative Base
Station(s).
The handset will choose the Base Station from which the strongest RSSI signal is received
as the first alternative Base Station. Alternative Base Stations are listed according to RSSI
values. If the “Best alternative Base Station” disappears, the next Base Station with the
highest RSSI value will become the “Best alternative Base Station.”
RSSI value display
The RSSI value of Base Stations can be viewed by the handset when used as a signal
meter. This value is related in a two-digit numerical format. However, the RSSI value
may be a three-digit value (i.e. greater than 99). In this case, the handset uses a
punctuation symbol to indicate this condition. This punctuation symbol should be read
as “100 + the number shown.”
For instance, to relate a RSSI value of 99, the digits 99 will be shown in the display. To
relate a RSSI value of 106, the value may appear as : 6 or ; 6. The punctuation value
shown may change; however, the meaning remains the same.
 To provide for quality speech, the RSSI value is normally not accepted as
lower than a loss of 25dB relative to the signal which is 100% measured near
to the KWS1500. If the signal loss rises to more than 25dB within the
desired coverage area, plan to install a KIRK Repeater to improve coverage.
When measuring for placement of Repeaters, the signal loss of the KWS1500
(or KIRK Repeater in a linear configuration) should not be higher than 25dB
at the location chosen for mounting the Repeater.
.
3.4 Using the Handset as a Signal Meter
During a site survey, the handset can be used as a signal meter to measure the radio
signal strength and bit-failure rate of the KWS1500 and Repeaters and determine their
optimal locations.
Radio coverage is measured by a combination of the Q-value and RSSI value, shown in
the handset’s display as described below. If the values are not adequate in a sector of the
coverage area (Signal loss of more than 25dB and Q-value less than 60), the KWS1500
may need to be moved to a better location, and / or KIRK Repeaters may need to be
installed.
 All signal measurements must be taken with the subscribed handset off-hook
and in a call to monitor voice quality.
 It is recommended to use a headset to assist with measuring radio signal
strength. This allows you to listen to the quality of the voice while
simultaneously viewing the signal values on the handset’s display screen.
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