Instruction manual

2-90
BreezeACCESS Version 4.5 Operations and Administration
Manual Revision: 1.0
" Noise Floor: Enables the user to set the equivalent noise level
that is affected by the thermal noise and the average
interference level.
Available values: -115 to –50 (dBm).
Default values:
IF-based units: -112(dBm)
SU-R: -101(dBm)
SU-I/AU-I: -97 (dBm)
" Carrier to Interference Difference Level: Enables the user to
set the minimal difference between the Current Noise Floor and
a “good” signal. In environment where there is a high probability
that the level of interfering signals may temporarily increase
significantly above the average level, this parameter should be
set to a higher value.
Valid values: 6 to 60(dB)
Default values:
IF-based units: 8(dB)
SU-R, SU-I, AU-I: 9(dB)
" Carrier Sense Level – This is the threshold level that is used
prior to initiating a transmission by the unit to determine the
existence of transmission from another unit. As long as the level
of a received signal is above this threshold, the unit will assume
that another unit is transmitting and will refrain from trying to
transmit in order to prevent collisions.
The actual level used by the SU as a threshold for decision on
the existence of a “good” signal (Runtime Carrier Sense Level)
may differ from the configured Carrier Sense Level, as described
in the Adaptive Thresholds section below.
Available values: -100 to -40 (dBm)
The Default Value is –90dBm for IF-based units and -85dBm for
other (single box) units.
! Adaptive Thresholds Parameters (SU only) - The interference
avoidance algorithm described above adjusts dynamically the
“Current Noise Level” to adapt to relatively fast changes in the
environment. The adaptive thresholds algorithm enables improved
rejection of interference in the SU units, in varied noisy
environments. On receiving, it reduces the number of erroneously
detected packets that are actually just noise (“bad packets”). On
transmitting, it provides a more accurate carrier sense, therefore
lowering erroneous collision detection. The algorithm changes the
actual level that is used as the Noise Floor, by adapting to actual
levels of received “good” signals. When the Adaptive Threshold