Alvarion SW VERSION 5.1 User Manual

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Chapter 4 - Operation and Administration 
 
BreezeACCESS VL System Manual
 
156 
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 4.2.6.2.14 on page 150) 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: 
4.2.6.2.18.1 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 
parameter, the calculated value will be used. Otherwise, the Forced Value will 
be used. 
The default option is Fully Automatic. 
4.2.6.2.18.2 Forced Value 
The Forced Value parameter enables configuring the Noise Floor to be used if the 
selected Calculation Mode is Forced. This is also the minimum value to be used if 
the selected Calculation Mode is Automatic with Minimum Value. 
If you decided to change the calculation mode to Automatic with Minimum Value 
and you still experience problems in the link (long association time, exceptionally 
low throughput), try to improve it by increasing the configured Forced Value. 
The available range is from -107 to -55 (dBm)