Wireless Access

last person joined: 8 hours ago 

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

Understanding the effects of non-WiFi interference

This thread has been viewed 12 times
  • 1.  Understanding the effects of non-WiFi interference

    Posted Sep 27, 2013 05:52 AM

    I have started using the spectrum analyzer features available for Aruba and I am hoping I can get a better understanding of the data through some expert comments.

     

    In the table below am I correct to say:

     

    1) the microwave ovens with strong signal and moderate duty cycle (20-30) will stop the wifi communication when the signal is present, but since it is not 100% duty cycle web pages and smaller items will load but performance will be drastically reduced?

     

    2) the video device that shows up near this AP with a weak signal -79 but high duty cycle, 99 would prevent this AP from operating, or is the signal weak enough that the AP will ignore it.  (is there a rough guide to estimate when the interfere power is low enough to be ignored and when the AP will take notice)

     

    3) a client sitting closer to the above video device and trying to use this AP would be knocked offline, or is it possible they would maintain the association but have a non functional network?

     

    Thanks,
    Matt


    Example:

    Non-WiFi Device Log Table: 2GHz
    -------------------------------
    Type              ID  CFreq(KHz)  Bandwidth(KHz)  Channels Affected  Signal(dBm)  Duty Cycle  Event    Time
    ----              --  ----------  --------------  -----------------  -----------  ----------  -----    ----
    Microwave         1   2466062     6000            11                 -46          22          Added    2013-09-26 14:56:49
    Microwave         1   2462749     6000            11                 -47          28          Deleted  2013-09-26 14:57:30
    Microwave         2   2463468     6000            11                 -50          33          Added    2013-09-26 15:01:28
    Microwave         2   2464843     6000            11                 -46          30          Deleted  2013-09-26 15:02:10
    Microwave         3   2465249     6000            11                 -44          32          Added    2013-09-26 15:30:16
    Microwave         3   2459500     6000            11                 -48          21          Deleted  2013-09-26 15:31:57
    Cordless Base FH  1   2444000     80000           11                 -81          5           Added    2013-09-26 16:07:46
    Microwave         4   2464749     6000            11                 -82          50          Added    2013-09-26 16:08:00
    Microwave         4   2465406     6000            11                 -82          12          Deleted  2013-09-26 16:08:17
    Video             1   2467156     6000            11                 -79          99          Added    2013-09-26 16:08:21
    Bluetooth         1   2444000     80000           11                 -82          5           Added    2013-09-26 16:09:02
    Video             1   2467156     6000            11                 -79          99          Deleted  2013-09-26 16:09:21
    Bluetooth         1   2444000     80000           11                 -82          5           Deleted  2013-09-26 16:09:27
    Cordless Base FH  1   2444000     80000           11                 -82          5           Deleted  2013-09-26 16:13:37
    Cordless Base FH  2   2444000     80000           11                 -80          5           Added    2013-09-26 19:20:37
    Bluetooth         2   2444000     80000           11                 -81          4           Added    2013-09-26 19:20:46
    Bluetooth         2   2444000     80000           11                 -82          1           Deleted  2013-09-26 19:21:22
    Cordless Base FH  2   2444000     80000           11                 -82          5           Deleted  2013-09-26 19:24:46


  • 2.  RE: Understanding the effects of non-WiFi interference

    EMPLOYEE
    Posted Sep 27, 2013 07:14 AM

    Having a lower duty cycle *could* mean it gives clients a better chance to operate, but you should not count on it.  Non wifi interfering devices should just be removed from the area when found.  Why?  Because, since they are do not follow the rules of wifi, they do not try to play nice with wifi devices, so there will always be a serious disruption.  It is at its worst if the interferring device is between two wifi devices that want to communicate.

     

     



  • 3.  RE: Understanding the effects of non-WiFi interference

    Posted Sep 27, 2013 07:54 AM

    Thanks for confirming that.
    What about the signal strength of the interferer, any idea on what level it will be ignored at, or will it at all?
    the blue tooth interferes people have beside their laptops are all low power, low signal strength, how bad are they?  (wireless keyboard and mouse)



  • 4.  RE: Understanding the effects of non-WiFi interference

    EMPLOYEE
    Posted Sep 27, 2013 08:06 AM

    Bluetooth is not bad compared to wireless video and microwaves.  In great enough quantity, it will cause problems, though.  Location is VERY important.

     



  • 5.  RE: Understanding the effects of non-WiFi interference

    EMPLOYEE
    Posted Sep 27, 2013 09:52 AM

    @MattV wrote:

    Thanks for confirming that.
    What about the signal strength of the interferer, any idea on what level it will be ignored at, or will it at all?
    the blue tooth interferes people have beside their laptops are all low power, low signal strength, how bad are they?  (wireless keyboard and mouse)


    It won't be ignored, but the ARM profile defines at what level it should change channel, amongst other things.  What command exactly was that output above from?



  • 6.  RE: Understanding the effects of non-WiFi interference

    Posted Sep 27, 2013 10:31 AM

    The command the output came from is

     

    show ap spectrum device-log ap-name <name of the ap>

    Would I be correct in assuming that the   ADD time is when the interference shows up, and the itnerference is continuosly there until the DELETE time?

    Thanks