Alvarion BreezeACCESS VL System Manual page 186

Chapter 4 - Operation and Administration
achieve optimal performance in certain deployments where the automatic ANI
mechanism may not function properly.
It is strongly recommended to consult with Alvarion experts before switching to
manual mode and modifying any of the parameters.
The general rules for using the Noise Immunity Control parameters are:
In the SU, if performance (Modulation Level) is lower than expected based on the
SNR, try switching to Manual mode without changing any of the parameters.
CAUTION
Do not change any of the SU's Noise Immunity Control parameters (except the Noise Immunity
State Control) from remote, as it may result in loss of connectivity to the unit.
In the AU, try switching to Manual mode if overall throughput is too low or if SUs
are lost although communication conditions are sufficient for good connectivity.
In many deployments the transition to Manual mode is sufficient. If not, you may
try changing the Noise Immunity Level and/or Spur Immunity Level parameters.
The target is to reduce the amount of Phy Error rate reported by the unit (see
Total Rx events on page 117). To ensure that sensitivity is not reduced too much
and SUs are not lost, verify that the Age (see Display Association Info on page
121) of all SUs is below 20 seconds.
Do not activate the OFDM Weak Signal parameter if the SNR is below 36 dB.
Under normal conditions, the OFDM Weak Signal should never be activated in
the AU, since the SNR of all SUs will be below 36 dB when ATPC is enabled.
The Noise Immunity Control submenu includes the following options:
4.2.6.2.17.1 Noise Immunity State Control
The Noise Immunity State Control defines the activation mode of the Adaptive
Noise Immunity mechanism: Automatic or Manual. The following parameters of
the Noise Immunity Control mechanism are applicable only for Manual mode.
The default is Automatic.
4.2.6.2.17.2 Noise Immunity Level
The Noise Immunity Level parameter sets the threshold for immunity against
broadband interfering signals. A higher value may reduce the number of errors at
the expense of reduced sensitivity.
The range is from 0 to 4. In the current version only 0 and 4 should be used.
The default is 0.
4.2.6.2.17.3 Spur Immunity Level
The Spur Immunity Level parameter sets the threshold for immunity against
narrow band interfering signals such as spurious from signals at other
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BreezeACCESS VL System Manual