5 GHz Spur Immunity


In highly congested or high dense deployment we might have observed high channel utilization in 5 GHz radio of an AP-130 Series access point in client association and throughput issues. In order to over come this situation starting from ArubaOS, the Spur Immunity feature got introduced.


Starting from ArubaOS, the Spur Immunity setting is introduced. Configure this setting if high channel utilization is observed in the 5 GHz radio of an AP-130 Series access point in a noise-free environment resulting in client association and throughput issues. This setting appears in the controller WebUI only if the AP model is AP-130 Series.

Spur Immunity for 5 GHz radio. This feature fine-tunes the Cyclic Power Threshold (CPT) of a 5 GHz radio. The value specified here is the offset from the base value of 2 dB (for example, setting the CPT value to 1 corresponds to 2 + 1 = 3 dB. Similarly, setting the CPT value to 10 corresponds to 2+10 = 12 dB).


We can configure this setting using the controller WebUI or CLI.

In the WebUI
Log in to the controller WebUI and follow the instructions below.
1. Navigate to the Configuration > WIRELESS > AP Configuration page.
2. In the AP Group tab, click the desired profile.
3. In the Profiles list, navigate to the RF Management > 802.11a radio profile menu.
4. In the Advanced tab of the Profile Details section, configure the Spur Immunity setting.


In the CLI
A new spur-immunity parameter can be configured, the 5 GHz spur immunity in the controller CLI as well is introduced in the rf dot11a-radio-profile command.
rf dot11a-radio-profile


Use this parameter when high channel utilization is observed in the 5 GHz radio of AP-130 Series access points in a noise-free environment causing client association or throughput issues.
Adjust the CPT value to eliminate the spur impacts. Range definition is as follows:
l 0: default CPT
l 1-19: CPT growth from default (3 dB to 21 dB)
l 20: Setting this parameter to 20 sets the cell-size-reduction value to 1. Cell-size-reduction is the receive coverage area of the AP.

NOTE: Configure this parameter under the supervision of Aruba Technical Support. 
NOTE: Setting the spur immunity to a higher value may decrease the AP RF coverage.
NOTE: This parameter is applicable for AP-130 Series access points only. The controller ignores this parameter if configured for non-AP-130 Series access points.

Range: 0-20 CPT, Default: o CPT


Wecan verify the configured value by executing the show rf dot11a-radio-profile command.

show rf dot11a-radio-profile

The following example displays the spur immunity value for an 802.11a radio.
(host) #show rf dot11a-radio-profile default
802.11a radio profile "default"
Parameter Value
--------- -----
Radio enable Enabled
Mode ap-mode
High throughput enable (radio) Enabled
Very high throughput enable (radio) Enabled
Channel 36
Transmit EIRP 15 dBm
Non-Wi-Fi Interference Immunity 2
Spur Immunity 0


Version history
Revision #:
6 of 6
Last update:
‎02-15-2019 01:11 PM
Updated by:
Labels (1)