Alvarion BreezeACCESS EZ AU-EZ, System Manual

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Chapter 4 - Operation and Administration Menus and Parameters
BreezeACCESS EZ AU-EZ 89 System Manual
4.2.6.2.14.6 Show Noise Immunity
Select this option to view the current values of the Noise Immunity Control
parameters, and some additional parameters of the ANI mechanism.
4.2.6.2.15 Noise Floor Calculation Parameters
The Noise Floor calculation mechanism incorporated in the units is used for
estimating the level of the noise floor. This value is used for estimating SNR values
and for decisions on existence of signals in the channel. In some cases, especially
when a very strong signal exists in neighboring channels, the noise floor
calculated by the built-in mechanism may be significantly below the actual noise
floor level.
Typically, the expected noise floor level (for a 20 MHz bandwidth) is -96 (dBm).
The default calculation mode is Fully Automatic, using only the built-in
mechanism. If you experience problems in the wireless link such as excessively
long association process or very low throughput, it may be caused by errors in
noise floor calculation. In this case, it is recommended to perform a Spectrum
Analysis (see
Section 4.2.6.2.11 ) and view the Average Noise Floor values. If the
calculated Noise Floor is lower by more than 5 dB from the expected value, it is
recommended to change the calculation mode to Automatic with Minimum Value,
using the expected value as the minimum (Forced Value).
Note that if the SNR of received signals is very low (typically below 10 dB), it is
recommended to maintain the default calculation mode (Fully Automatic).
Changing the calculation mode to Automatic with Minimum Value may result in
loss of connectivity with units for which the calculated SNR before the change was
relatively low.
The Noise Floor Calculation Parameters submenu includes the following options:
4.2.6.2.15.1 Calculation Mode
The Calculation Mode defines the method used for calculation the Noise Floor
value to be used by the device for estimating the quality of received signals. The
available options are:

Fully Automatic: According to the built-in noise floor calculation mechanism.

Forced: The Noise Floor value is set manually to the value configured for the
Forced Value parameter (see below). Typically this mode should be used only
for special testing purposes.

Automatic with Minimum Value: If the calculated Noise Floor using the
built-in mechanism is higher than the value configured for the Forced Value