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Ask about the method of measuring average RSSI (avg-rssi) in ArubaOS

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  • 1.  Ask about the method of measuring average RSSI (avg-rssi) in ArubaOS

    Posted Jan 30, 2023 06:18 AM
    Dear Aruba community,

    I'm retrieving RSSI data from interfering APs using the command: "show ap monitor ap-list ap-name <ap name>".

    Just a small but very helpful question for me, does anyone know the exact difference between current RSSI (curr-rssi) and average RSSI (avg-rssi)? 

    Specifically, what is the method that Aruba using to calculate the avg-rssi? How long do they measure as average value?

    current rssi and average rssi
    I read the description in show ap monitor association
    Arubanetworks remove preview
    show ap monitor association
    show ap monitor ap-list ap-name {containment-exclusion} | {wifi-direct [ all ]} bssid ip-addr ip6-addr This command shows the list of APs being monitored. The following example displays the Monitored AP table, which lists all the APs monitored by a specified AP or BSSID (For versions prior to ArubaOS 8.9.0.0).
    View this on Arubanetworks >
      (as picture below) but it seems not very clear about the method of average RSSI or SNR.


    Thank you for your advice


  • 2.  RE: Ask about the method of measuring average RSSI (avg-rssi) in ArubaOS

    EMPLOYEE
    Posted Jan 31, 2023 09:25 AM
    I have not seen anywhere what is the interval for the average RSSI, most values in the controller are in range between few minutes and 15-30 minutes. The average value is probably only there to average out very jumping values of the average RSSI.

    What is it what you would like to do with that data? Note that the R in RSSI stands for relative and that makes it unusable for most things, except for comparing to other values of the same type and see if they are higher/equal/lower.

    ------------------------------
    Herman Robers
    ------------------------
    If you have urgent issues, always contact your Aruba partner, distributor, or Aruba TAC Support. Check https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.

    In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
    ------------------------------



  • 3.  RE: Ask about the method of measuring average RSSI (avg-rssi) in ArubaOS

    Posted Feb 01, 2023 09:14 PM
    Hi, 

    Thank you for the quick response. Do you know the time interval in the controller? The curr-rssi might be captured in the interval as I understand. 

    I want to deal with the RSS-distance based algorithm, and see the difference between curr-rssi and avg-rssi. Because curr-rssi is changing in all the new samples, so I can see which one should I use to provide more accurate distance.


  • 4.  RE: Ask about the method of measuring average RSSI (avg-rssi) in ArubaOS

    EMPLOYEE
    Posted Feb 06, 2023 05:43 AM
    RSS based distance is 'a can of worms'. As mentioned, it's a relative value, which means you cannot really use it for measuring distance because there is no calibrated dB (or absolute) value that you can use to calculate the free-space path loss. The values will give you an indication at best, also because different APs are on different channels, so will see the clients differently.

    If your clients are stationary (don't move), the avg-rssi probably is best; if they move the actual value may be better where you have the option to 'smoothen' the value by creating your own average that you control. There are products specifically around this locationing problem like Aruba Analytics and Location Engine, Central Location Engine, but also Aruba Central and Airwave have a floorplan feature that can locate clients. All have differing results in accuracy as using RSSI or actual signal strength appears to be unreliable and heavily dependent on the client, environment, AP density, etc.

    If you just need to know to which AP a client is closest, that would be more likely to work, but you would need to make your expectations/requirements more clear.

    You may have a discussion with your local Aruba partner or Aruba SE to discuss the feasibility of your plan.

    ------------------------------
    Herman Robers
    ------------------------
    If you have urgent issues, always contact your Aruba partner, distributor, or Aruba TAC Support. Check https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.

    In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
    ------------------------------