Wireless Access

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Access network design for branch, remote, outdoor and campus locations with Aruba access points, and mobility controllers.
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Power maximisation issue

  • 1.  Power maximisation issue

    Posted Sep 06, 2017 05:54 AM

    Dear Aruba staff , 

    i am using Aruba mobility controller 7010 and AP 207 , in a campus AP environmnet , i configured both the 802.11a and 802.11g radios to transmit EIRP = 30 , but when going through the following commands :

    #show ap  active  and  #show ap radio-database  i found that the power of the 802.11g power is only 20 as a current value and maximum value of 20 also , and the power of 802.11a is 23 for some APs and 26.5 for other APs and maximum value of 23 and 26.5 respectively , i have 10 APs connected to aruba 2920 switch , "this switch is giving POE only to these 10 APs" , kindly find the controller logs and some screenshots from the dashboard and please explain why the power is only 20 in 11g radio and 23 and 26.5 in 11a radios , and why i have 2 values of power in 11a radios . and how to force the power to be 30 "EIRP" in both radios. 


    controller-logs.txt   5K 1 version

  • 2.  RE: Power maximisation issue

    Posted Sep 06, 2017 07:29 AM

    Each access point has power restrictions for each regulatory domain when approved.  I have not seen a regulatory body approve 30 EIRP in any indoor access points.  Please check your local regulatory body's restrictions on RF power.


    Please use:

    show ap allowed-max-EIRP ap-name <name of ap> 

    ..to find out what the max EIRP of each AP is for each channel for the configured regulatory domain. 

  • 3.  RE: Power maximisation issue

    Posted Sep 06, 2017 12:56 PM

    Transmit power is restricted by a number of factors:

    - Regulatory (depends on country, channel, antenna gain, etc.)

    - Capabilities of the hardware (radio). This is typically a limit in the conducted power per radio chain. The EIRP power limit includes MIMO gain (for example, 3dB for a 2x2 radio), antenna gain, etc.

    - ARM limit or manual setting


    The actual limit is the minimum of all of these..

  • 4.  RE: Power maximisation issue

    Posted Sep 06, 2017 03:41 PM

    Thanks Onno and Colin ,

    but why with the same AP type , same AP group and same configuration it show 2 different power limits "for 802.11a it showed 23 and 26.5 EIRP"

  • 5.  RE: Power maximisation issue

    Posted Sep 06, 2017 05:17 PM

    Same channel as well? Same software and DRT file versions?

  • 6.  RE: Power maximisation issue

    Posted Sep 06, 2017 05:21 PM

    From where can i get this information ? 

  • 7.  RE: Power maximisation issue

    Posted Sep 06, 2017 07:12 PM

    Your screenshot shows one AP on channel 44+, the other on 161-

    It is expected to see differences in regulatory power limits between 5GHz sub bands, and even between channels in the same sub band.

    You can check the regulatory limits per channel by issuing the following command from the CLI:

    Show ap allowed-max-EIRP ap-name <name>

  • 8.  RE: Power maximisation issue

    Posted Sep 07, 2017 07:25 AM


    kindly find attached the output of the command :


    show ap allowed-max-EIRP ap-name <name of ap>

    for some of the APs i have in the deployment . what is the difference between b , g/a  , HT20 , HT40 and VHT 80 .are the g/a the same as 802.11a and 802.11g ?

     I can see that i can use power of 36 in some channels with g/a option . isn't it right ? 

    And how to manually choose the channel of each AP manually?

    also find attached some screenshots for the clients and APs from the dashboard . are these SNR values acceptable ? and what is the minimum acceptable SNR value ?


    power limit AP.txt   7K 1 version

  • 9.  RE: Power maximisation issue

    Posted Sep 07, 2017 07:46 AM

    Please take a look at the 802.11ac validated reference design guide here:  http://community.arubanetworks.com/aruba/attachments/aruba/Aruba-VRDs/61/1/Aruba%20802.11ac%20Networks%20VRD.pdf


    It will answer many of your questions.