Controller Based WLANs

Do ArubaOS 3.3.1 and 3.3.2 support 802.11d and Transmit Power control (TPC)?

Product and Software: This article applies to ArubaOS 3.3.1 and 3.3.2.x.

 

ArubaOS 3.3.1.x supports 802.11d.

 

The 802.11d support includes the country element in the beacons and probe responses. Here is an example of that element in a beacon:

 

Country
Element ID: 7 Country
Length: 6
Country Code: US
Starting Channel: 1
Number of Channels: 11
Max Tx Power (dBm): 33

ArubaOS supports Transmit Power Control (TPC), which is part of 802.11h. However, the default transmission behavior has changed between version 3.3.1.x and 3.3.2.x as follows.

In ArubaOS 3.3.1.x, the beacon advertised the country with no knob to disable it while TPC was disabled by default:

 

Country
Element ID: 7 Country
Length: 6
Country Code: US
Starting Channel: 1
Number of Channels: 11
Max Tx Power (dBm): 33

 

When TPC (802.11h) is enabled, an additional element is available:

 

Power Constraint
Element ID: 32 Power Constraint
Length: 1
Local Power Constraint: 18 dB

where the Local Power Constraint = Max Tx power - AP Tx power.

From this displayed information, we conclude that the AP Tx power including the Antenna gain is:

33 - 18 = 15 dBm.

 

In ArubaOS 3.3.2.x, both elements are grouped together and set as disabled by default, that is, no country or power constraint was advertised.

 

Both elements can be enabled by enabling TPC in the radio profile (in the CLI, it is 802.11h):

Transmit Power 15 dBm
Advertise TPC Capability Enabled
Spectrum load balancing Disabled

 

Note: The default TPC setting in ArubaOS 3.3.1.x and 3.3.2.x is Disabled.

Version history
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Last update:
‎07-01-2014 01:42 PM
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