ExtremeIQ Cloud

View Spectrum Intelligence Details

The Spectrum Intelligence data panel contains the following information:

Status Bar

The status bar at the top of the panel displays the current analysis parameters, including which AP or APs are running the scan, the channels, run time, band (2.4 GHz or 5 GHz). You can change these settings for each and then select Apply.

Below the status bar, on the right side of the panel you will see the time remaining in the current scan and a Stop button. Select Stop to end the current analysis.

Note

Spectrum analysis automatically shuts down after 30 minutes.

Data Collect Interval: The data collection interval refers to the time interval between scans of the spectrum. Each time the AP scans the spectrum, it updates the display. If the data collection interval is five seconds, then the AP scans every five seconds and updates the display. You can change the interval from 1 to 30 seconds. The default is a one-second interval.

Graphical Analysis Feedback

This area displays graphs of the received signals, arranged by default in a two-by-two array. Use the expand and collapse arrows in the upper right corner of each graph to enlarge or reduce the graph for visibility.

The following graphs are displayed:

Real-time FFT: The real-time FFT trace indicates the power of a signal (vertical axis) along a domain of frequencies (horizontal axis). The term FFT refers to the mathematical algorithm used to break down received signals into their component frequencies. There are two traces in this display: the red trace indicates the real-time power levels, and the gray trace indicates the maximum power level reached during the current session. Maximize this graph to see the following additional display parameters:

Band: You can choose which band you want to monitor in this display: 2.400-2.500 GHz, 5.150-5.350 GHz, 5.470-5.725 GHz, or 5.725-5.850 GHz.

Channels: Choose one of the channel combinations in the drop-down list to display channel boundaries within the graph.

Center: Use this control to scroll the graph right or left. You can use the Center control in combination with the Span control to zoom in on a specific area of the frequency domain.

Span: This control establishes the width of the viewable area, effectively zooming in on the center frequency. Use this control in concert with the Center control to zoom in on a specific area of the frequency domain.

Reference Level: By default, the reference level of the graph (the top line) is 0 dBm. When used in conjunction with the Vertical Scale control, you can zoom in on a specific portion of the actual trace. By changing the reference level using this control, you can also view very low power levels near the noise floor. In a very quiet environment, the noise floor is generally between -130 dBm and -90 dBm; in very noisy or busy environments it is much higher.

Vertical Scale: The vertical scale of a graph indicates how much vertical distance on the graph corresponds to power. By default, the vertical scale is set to 10 dB, which means that a power change of 10 dB corresponds to a specific, physical vertical distance on the graphic display. Changing that setting to 5 dB doubles the vertical resolution of the graph. Because there are many different sizes of monitors, the actual scale that you see in your browser is relative.

Max Hold: By default, this check box is selected and displays the gray trace that indicates the maximum power level reached during the current data collection session. To turn off the gray trace, clear the check box.

FFT Duty Cycle: The FFT duty cycle is the amount of time as a percent of total time that the AP receives a signal 20 dB or more above the noise floor. The FFT duty cycle is often referred to as channel utilization because it indicates to what extent a channel is actually in use in terms of the relative amount of time the signal is present (vertical axis). Within this display, there are two traces: the red trace indicates the real time duty cycle, whereas the gray trace indicates the maximum duty cycle reached during this data collection session. This graph displays information for up to 20 SSIDs. Neighbor AP Overlay: Hover your mouse over the overlay on the chart to see more information about neighboring AP SSIDs.

Maximize this display to see the following additional parameters:

Band: You can choose which band you want to monitor in this display: 2.400-2.500 GHz, 5.150-5.350 GHz, 5.470-5.725 GHz, or 5.725-5.850 GHz.

Channels: Choose one of the channel combinations in the drop-down list to display channel boundaries within the graph.

Center: Use this control to scroll the graph right or left. You can use this control in combination with the Span control to zoom in on a specific area of the frequency domain.

Maximum: By default, the maximum is set to 100%. This means that when the trace reaches the top of the graph, it has a duty cycle of 100%. You can use this control to set a lower maximum to gain resolution. When used with the Minimum control, you can zoom in on a specific portion of the trace.

Minimum: By default, the minimum is set to 0%. This means that when the trace reaches the bottom of the graph, it has a duty cycle of 0%. Use this control to set a higher minimum for better resolution. When used with the Maximum control, you can zoom in on a specific portion of the trace.

Max Hold: By default, this check box is selected and ExtremeCloud IQ displays the gray trace that indicates the maximum duty cycle reached during this data collection session. To turn off the gray trace, clear the check box.

Swept Spectrogram: A swept spectrogram tracks the signal power over time. It produces a color-coded sweep of spectral information that shows the real time FFT in terms of its historical values. The swept spectrogram—also called a heat map—reports the frequency on the horizontal axis, the history (in sweeps) on the vertical axis, and the power encoded as a set of colors. Blue indicates low power levels, red indicates high power levels, and the gradients from light blue through green, yellow, and orange, indicate intermediate power levels. Maximize this display further to see the following additional parameters:

Band: Select the band that you want to monitor in this display: 2.400-2.500 GHz, 5.150-5.350 GHz, 5.470-5.725 GHz, or 5.725-5.850 GHz.

Channels: Choose one of the channel combinations in the drop-down list to display channel boundaries within the graph.

Swept Spectrogram-FFT Duty Cycle: A swept spectrogram of the FFT duty cycle tracks the duty cycle over time. This spectrogram produces a color-coded sweep of duty cycle information with frequency on the horizontal axis, history (in sweeps) on the vertical axis, and the duty cycle encoded as a set of colors. Blue colors indicate low duty cycle (the darkest blue is 0%), whereas red colors indicate high duty cycles (the darkest red is 100%); the gradient of colors from light blue, through green, yellow, and orange, indicates intermediate duty cycle values. Maximize this display to see the following additional parameters:

Band: You can choose which band you want to monitor in this display: 2.400-2.500 GHz, 5.150-5.350 GHz, 5.470-5.725 GHz, or 5.725-5.850 GHz.

Channels: Choose one of the channel combinations in the drop-down list to display channel boundaries within the graph.

Both swept spectrograms together provide a useful view of how the RF environment behaves over time, which in turn provides clues to uncovering problems, such as identifying intermittent interference sources.

Interference Reporting

The Interference Signature table below the graphs displays any sources of RF interference that the spectrum analyzer can identify. This area provides a summary of all interference sources for quick review. This area contains six columns to help identify the affected channels and the approximate position of the interference.

Extreme Device Name: The name of the AP that is reporting the interference. If an interference source is reported by a few APs, but not others, you can use this to approximate the physical location of the interference.

Device Function: Indicates the device type of the interferer, such as a cordless phone, microwave oven, or video bridge. The device type listing can help determine whether the interference source might be a security concern.

Discovered: Shows the date and time that the AP discovered the source of the interference. You can track regular, periodic, and intermittent interference sources using this information.

Channel Affected: When ExtremeCloud IQ identifies an interference source, the channel in which it occurs appears here.

Center Frequency: The center frequency is the midpoint between upper and lower frequency band cutoff.

Occupied Bandwidth: This column displays the bandwidth of the affected range of frequencies.

The last three columns contain redundant information and provide the same information from different perspectives so that you can gain a more a complete understanding of the affected frequencies and channels.

Note

Interference signatures also appear as active alerts on the Manageand Dashboard Alarms tab.