Wireless Access

last person joined: an hour ago 

Access network design for branch, remote, outdoor and campus locations with Aruba access points, and mobility controllers.
Expand all | Collapse all

Radio Power Settings

This thread has been viewed 52 times
  • 1.  Radio Power Settings

    Posted Sep 12, 2021 12:10 PM
    VHD Campus Deployment - walled (classroom) environment
    Mix of AP's 205/225/515/535  -  75% are 515/535 , just waiting on replacement AP's to ship.

    Seeing some clients hang on 2.4 ghz longer than they should.

    What should my radio power settings be ?  Currently they are :

    2.4
    Min - 6
    Max - 12

    5
    Min - 15
    Max - 21

    Thx

    ------------------------------
    Mike Robertson
    ------------------------------


  • 2.  RE: Radio Power Settings

    Posted Sep 12, 2021 01:33 PM
    It will not always be 100%.  Some clients prefer the 2.4ghz band or do not support the channels on the 5ghz band radio of that specific AP.

    To get a sense of your 5ghz uptake by 5ghz capable clients, type the following on the Mobility Controller:

    show ap association | begin Total

    ------------------------------
    Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
    ------------------------------



  • 3.  RE: Radio Power Settings

    Posted Sep 12, 2021 06:12 PM
    Which radio the endpoint will use is a decision in the client driver and is based on a complex algorithm nobody have the answer to, this is different for any vendor. This is also known as "the green diamond", more information at https://wlanprofessionals.com/decoding-the-green-diamond-understanding-client-behavior/

    One of the many decision makers its the signal RSSI measurement, but there are many many more attributes for the decision. For example Apple make decision as last known good experience.

    There are some small things you can do.

    1. To make the 2.4GHz and 5GHz radio equal in cell size and power, plan the 2,4GHz radio -6dBm tx-power as the 5GHz radio to create equal cell sizes.
    2. Enable band-steering with prefer 5GHz. But! Band steering is not a IEEE standardization and work different between different vendors, sometimes it helps you, sometimes things get worse.
    3. Disable 2.4GHz, or create to separate SSID's one for each radio.

    ------------------------------
    Marcel Koedijk | MVP Guru 2021 | ACEP | ACMP | ACCP | ACDP | Ekahau ECSE | Not an HPE Employee | Opionions are my own
    ------------------------------



  • 4.  RE: Radio Power Settings

    Posted Sep 13, 2021 08:44 AM
    Thanks for the reply 

    Results on controller 1 

    (Aruba7210) *#show ap association | begin Total
    Total num of dual-band capable clients:333
    Total num of dual-band capable clients in 2.4G band:0
    Total num of dual-band capable clients in 5G band:333
    Total num of single-band only clients:90

    Results on controller 2 

    (Aruba7210_B) *#show ap association | begin Total
    Total num of dual-band capable clients:281
    Total num of dual-band capable clients in 2.4G band:0
    Total num of dual-band capable clients in 5G band:281
    Total num of single-band only clients:120



    ------------------------------
    Mike Robertson
    ------------------------------



  • 5.  RE: Radio Power Settings

    Posted Sep 13, 2021 08:47 AM
    Unless there is a bug, that looks good.

    ------------------------------
    Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
    ------------------------------



  • 6.  RE: Radio Power Settings

    Posted Sep 13, 2021 09:07 AM
    Do you think it's feasible for me to shut down the 2.4ghz radio all together?

    ------------------------------
    Mike Robertson
    ------------------------------



  • 7.  RE: Radio Power Settings

    Posted Sep 13, 2021 09:10 AM
    No.  There are still 2.4ghz band only clients, so 2.4ghz needs to stay on.  The numbers say that all of the dual band devices are on the 5ghz band.  That is good.

    ------------------------------
    Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
    ------------------------------



  • 8.  RE: Radio Power Settings

    Posted Sep 13, 2021 09:22 AM
    Ok - fair enough 

    A different but similar question.  As clients move and hop from AP to AP.  What is a realistic time expectation for them to switch from 2.4 ghz to 5 ghz?

    So - a client is connected in Room A on 5ghz - all the world is well.  That client physically moves across the hall - still very much in range of the AP in Room A, and it switches to 2.4ghz to remain connected.  However, there is an AP in Room B directly overhead.

    What is the realistic amount of time that client will disconnect from the AP in room A on 2.4 ghz and switch to 5 ghz on the AP in room B ?

    ------------------------------
    Mike Robertson
    ------------------------------



  • 9.  RE: Radio Power Settings

    Posted Sep 13, 2021 09:47 AM
    To be frank, the client controls all aspects of roaming to and from bands.  Aruba can do things to influence it by moving it with 802.11v if it is supported, sending deauths and allowing the 2.4ghz radio to respond after the 5ghz band to a client if it knows a client is dual-band.  In the end-however, the client decides what AP and band it connects to.  Making the 5ghz power higher than the 2.4ghz band can certainly influence client roaming behavior, as well.

    The short answer is there is no universal realistic amount of time a client will disconnect from 2.ghz and then connect to the 5ghz band.

    ------------------------------
    Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
    ------------------------------



  • 10.  RE: Radio Power Settings

    Posted Sep 13, 2021 10:29 AM
    Thanks for the input.   A real challenge when you are dealing with these BYOD school environments.  I don't think I'm in terrible shape - if my clients are connected to these 500 series AP's on 5 ghz - they can push 150 - 500 Mbps up and 150 - 500 Mbps down depending on the number of clients connected.  I just have to figure out how to deal with these 2.4ghz sticky clients

    ------------------------------
    Mike Robertson
    ------------------------------



  • 11.  RE: Radio Power Settings

    Posted Sep 13, 2021 11:34 AM
    What are the 2.4ghz sticky clients that you are dealing with?

    The more dual band clients attach to 5ghz, the better the experience for 2.4ghz-only clients or for dual band clients that happen to end up on 2.4ghz.  Clients can certainly push 150Mpbs, but only in bursts.  It is typically not constant.  As long as you have enough APs to spread clients out among them, that is good.

    ------------------------------
    Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
    ------------------------------



  • 12.  RE: Radio Power Settings

    Posted Sep 13, 2021 01:41 PM
    Hi Mike,

    Which radio the client will pick up is a client (driver) decision. Also check if your running the lastest wlan drivers on your client.

    What are you basic and transfer modulation rate settings?

    When disable the lower basis and transfer rates clients need a stronger signal keep the supported modulation rates. Disable the lower rates can help you in optimize roaming and optimize airtime.

    ------------------------------
    Marcel Koedijk | MVP Guru 2021 | ACEP | ACMP | ACCP | ACDP | Ekahau ECSE | Not an HPE Employee | Opionions are my own
    ------------------------------



  • 13.  RE: Radio Power Settings

    Posted Sep 13, 2021 12:06 PM
    I also wonder what type of clients you are referring to.  We have been operating with Aruba Wireless in a university environment since 2007 and I have not seen any substantial issues with sticky clients for years.  As far as BYOD goes, we don't really have any significant issues, but, if the client is at fault, we will let the user know and they can either decide to deal with it or use something else.

    ------------------------------
    Jim Lucas
    ------------------------------