User guide

76 Chapter 6: Analyzing Spectrum Data
AirMagnet Spectrum XT User Guide
The text message at the bottom of the Channel Power Configuration dialog box changes with the
parameter you select. It provides a brief description of the parameter being selected.
Channel Duty Cycle
The percentage of time that the RF energy is present in the channel above the noise floor. The
duty cycle calculation is done by summing up the duration of all pulses that are detected
within the bandwidth of a channel. There are actually two accumulators, one for pulses that
are determined to be 802.11 pulses and another for pulses that are not 802.11 packets. The
WLAN duty factor (or channel utilization as we refer to it) is computed by dividing the
accumulated 802.11 WLAN pulse time by the time the radio was dwelling on that channel.
The non-WLAN duty factor is computed by dividing the accumulated time of non-WLAN
pulses with the total channel dwell time. See Figure 6-13.
Channel Power
Type
Select one of the following:
• Envelope - The highest energy reading that has been reached at a particular
frequency with a frequency range. See the description at the beginning of
this section.
• Integrated - The total summation of energy reading of an entire frequency
range. See the description at the beginning of this section.
Minimum Power Allows the user to set or change the minimum power value in dBm in the Y-axis
of the Channel Power graph. By default, the minimum power value is -120, but
you can change it to any value as low as -140.
Peak Power Allows user to set or change the peak power value in dBm in the Y-axis of the
Channel Power graph. By default, the Peak Power value is -20, but you can
change it to any value less than 0 dBm. Highlight the existing Peak Power value
and override with a new value.
Start Channel Allows the user to set the first channel in the range of channels to be selected.
Highlight the existing value and override it with a new value.
Stop Channel Allows the user to set the last channel in the range of channels to selected.
Highlight the existing value and override it with a new value.
Table 6-5: Configuring Channel Power Graph Parameters
Parameter Description