Spectrum Monitoring

Use spectrum monitoring to examine the radio frequency (RF) environment in which the Wi-Fi network is operating, identify interference and classify its sources. Analyze the results to isolate issues with packet transmission, channel quality, and traffic congestion caused by contention with other devices operating in the same band or channel.

Prerequisites

  • The Radio Mode on the target AP is set to Spectrum. For more information, see Radio Profiles.

  • The target APs are operating in the 2.4 GHz or 5 GHz frequency bands. Spectrum monitoring is not supported in the 6 GHz frequency band.

  • The target AP is running a minimum firmware version of 10.7.2 or 10.8.0.

Initiating Spectrum Monitoring

  1. In the HPE Aruba Networking Central landing page, select a site from the Sites menu.

    Alternatively, you can click the expand icon on the Sites menu to search for a site from the list.

    The site dashboard is displayed along with site health, device, and client information.

  2. Click Network.

    The Unified Device List (UDL) view is displayed for the site.

  3. To access the troubleshooting page for an AP, complete one of the following steps:

    1. From the Devices table in list view, click anywhere on the particular device row under Any or Access Points tab.

      The selected AP panel is displayed on the left.

    2. From the Devices table in list view, click on the particular device under the Access Points tab.

      The selected AP context page is displayed.

  4. Click the troubleshooting icon .

    The Troubleshoot page is displayed for the device, and the Tests tab is selected by default in the left panel.

  5. Open the Live Monitoring tab. Select Spectrum Monitoring.

  6. Click Start.
    A spectrum monitoring session is initiated. Data is sampled in five second intervals for 15 minutes.

    Note: Concurrent spectrum monitoring sessions are not supported; each HPE Aruba Networking Central instance allows one session at a time.

  7. Click Stop to end the session before 15 minutes pass.
    Click the Summary icon to view spectrum monitoring data in two charts—Channel Utilization and Channel Quality.
    Use the List icon to view interfering device details. Use the Export button to download the data as a CSV file to your local system.

Channel Utilization

The Channel Utilization graph indicates the percentage of channel utilization for Availability, Interference, and Wi-Fi Utilization categories associated with 2.4 GHz and 5 GHz radios.

Table 1: Channel Utilization Metrics

Metrics

Description

Channel

The channel number of the radio.

Available

The percentage of the channel currently available for use.

Interference

The percentage of the channel currently used by interfering devices.

Microwave

The percentage of the channel currently used by microwaves.

Common residential microwave ovens with a single magnetron are classified as a microwave. These types of microwave ovens may be used in cafeterias, break rooms, dormitories, and similar environments. Some industrial, healthcare, or manufacturing environments may also have other equipments that function like a microwave. This may also be classified as a microwave device.

Bluetooth

The percentage of the channel currently used by Bluetooth devices.

Any device that uses the Bluetooth protocol to communicate in the 2.4 GHz band is classified as a Bluetooth device. Bluetooth uses a frequency hopping protocol.

Cordless Phone

The percentage of the channel currently used by cordless phones.

Wi-Fi Utilization

The percentage of the channel currently used by Wi-Fi devices.

Channel Quality

The Channel Quality graph displays the channel quality corresponding the Wi-Fi and non Wi-Fi devices connected to the radios.

Table 2: Channel Quality Metrics

Metrics

Description

Channel

The channel number of the radio.

Quality

Current relative quality of the channel.

Known APs

Number of valid Instant APs identified on the radio channel.

Unknown APs

Number of invalid or rogue Instant APs identified on the radio channel.

Max AP Signal

Signal strength of the Instant AP that has the maximum signal strength on a channel in dBm.

Max Interference

Signal strength of the non-Wi-Fi device that has the highest signal strength in dBm.

Max AP SSID

The network SSID with maximum APs.

Max AP BSSID

The network SSID with maximum APs.

SNIR

The measure of SNIR detected in the network in dB.

Noise Floor

The noise at the radio receivers of the radios.

List View—Interfering Devices

To view the details about interfering devices detected by the spectrum scanner, click on the List icon .

Table 3: Interfering Devices Table

Metrics

Description

Type

Device type. This parameter can be any of the following:

  • Audio FF (fixed frequency)
  • Bluetooth
  • Cordless base FH (frequency hopper)
  • Cordless phone FF (fixed frequency)
  • Cordless network FH (frequency hopper)
  • Generic FF (fixed frequency)
  • Generic FH (frequency hopper)
  • Generic interferer
  • Microwave
  • Microwave inverter
  • Video
  • Xbox

ID

ID number assigned to the device by the spectrum monitor. Spectrum monitors assign a unique spectrum ID per device type.

Central Frequency

Center frequency of the signal sent from the device.

Bandwidth

Channel bandwidth used by the device in KHz.

Affected Channels

Radio channels affected by the wireless device.

Signal Strength

Strength of the signal sent from the device measured in dBm.

Duty Cycle

The device duty cycle. This value represents the percent of time the device broadcasts a signal.

First Seen

Time at which the device was first detected.

Last Seen

Time at which the device status was updated.