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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Extremely Poor Signal Strength

  • 1.  Extremely Poor Signal Strength

    Posted Jun 03, 2019 07:27 PM

    Hey guys, I have a wireless network with a building that's two stories, roughly 24,000 sq. ft. I have 5 Aruba 207s on the first floor (attached) and 4 upstairs roughly directly above the red ones in the attached picture, which shows the first floor locations. The access point in blue is roughly 45 ft. from the front, back and near side wall, for reference.

     

    Also attached is the signal strength measurements for several clients, and it's horrible. Standard office with normal drywall and metal studs.

     

    I'm sure I have some problems with the 2.4 GHz channels overlapping since my signals are definitely overlapping, which I'll fix tonight.

     

    The APs are set to auto ARM and the downstairs APs have chosen the following power settings on their 2.4 GHz radios:

    Left AP: 23 dB

    Top left AP: 18

    Top right AP: 18

    Right AP: 23

    Center AP (blue): 6

     

    So, definitely too strong... but, channel overlapping doesn't explain the 5 GHz band being super, super slow with horrible signal strengths. I have no interfering APs or rogue networks coming in from the outside.

     

    What else could cause the poor signal strength on the devices that are connecting to channels 60+, 108+, and 124+? The noise on every single AP is -90 dB +/- 5 dB, so at least that's consistent.

     

    The devices are all within 40 ft. of their AP and connecting to the proper AP, so it's not channel overlaps.Screen Shot 2019-06-03 at 6.08.08 PM.pngScreen Shot 2019-06-03 at 6.24.28 PM.png



  • 2.  RE: Extremely Poor Signal Strength

    Posted Jun 03, 2019 09:04 PM

    What are the walls made of?  It is unlikely that access point coverage will penetrate sufficiently through 3 walls or more to provide good client coverage.  If this was an open floor plan, instead of rooms, you would have better coverage.

     

    Was a predictive or actual RF survey done of this location before deployment?



  • 3.  RE: Extremely Poor Signal Strength

    Posted Jun 03, 2019 10:09 PM

    That's what's weird. Before we upgraded to Arubas, there were only 3 APs upstairs and 2 downstairs, and the wifi service was only troublesome in the bottom right corner offices of the diagram.

    You can literally stand underneath an access point with a clear line of sight no more than 3 feet away and get a poor signal.

     

    Nothing about this makes any sense.



  • 4.  RE: Extremely Poor Signal Strength

    Posted Jun 03, 2019 10:19 PM

    I just took the network down to 1 AP only, and forgot and rejoined the network, and it took me 4 tries of typing in the wifi password before it let me on. I did not mistype it at all.

     

    So weird.



  • 5.  RE: Extremely Poor Signal Strength

    Posted Jun 04, 2019 01:14 AM
      |   view attached

    No, we're never done a wireless survey. We've just done dozens (if not over a hundred) of similar projects just like this with metal studs and regular old drywall. I'm convinced that *actual* signal strength isn't an issue.

     

    Attached here is an example of me running wifi connection test at various locations running off of only ONE access point: the top left one with the dot in the middle of the AP circle.

     

    The first is whether my Mac connected with the .11ac or the .11n protocol. The second line is what the AP web GUI says my signal strength is. The third line is the RSSI reading directly from my MacBook.

     

    As you can see, just ONE access point covers nearly 100% of the first floor with its power setting automatically set at 27 dB. I'm even connecting just fine to this first-floor AP from the second floor 50 ft. away on the .11n 2.4 band.



  • 6.  RE: Extremely Poor Signal Strength

    Posted Jun 04, 2019 04:05 AM

    You wouldn't survey or run an access point at the highest transmit power.  If a user remains connected to the access point all the way on the other end of the floor, they will degrade the performance of all other clients on that access point, even though they would appear to have good signal strength.

     

    Is this a low-density environment?  What is the "noise" parameter for each of those access points?  Noise or interference could decrease the performance of those devices.  There may also be other factors in that environment that we cannot see like possibly attenuators in the walls.  It is hard to say with the limited information provided.



  • 7.  RE: Extremely Poor Signal Strength

    Posted Dec 19, 2019 08:37 PM

    We have seen some similar cases and only found that restoring an earlier backup of the config or resetting to factory defaults and then setting up the WiFi again fixed the problem. I suspect it might have been related to a firmware update and how it handels old legacy stuff but I can't see anything that stands out as different in the configs either. Take it as you want but I would suggest get the latest firmware installed, factory reset and set it up again, didn't take that long for us and solved a string of dropouts, low signal strength and slow speed/ping response issues that had been reported by users.



  • 8.  RE: Extremely Poor Signal Strength

    Posted Dec 21, 2019 01:11 PM

    @KevJB wrote:

    We have seen some similar cases and only found that restoring an earlier backup of the config or resetting to factory defaults and then setting up the WiFi again fixed the problem. I suspect it might have been related to a firmware update and how it handels old legacy stuff but I can't see anything that stands out as different in the configs either. Take it as you want but I would suggest get the latest firmware installed, factory reset and set it up again, didn't take that long for us and solved a string of dropouts, low signal strength and slow speed/ping response issues that had been reported by users.


    Restoring a backup, depending on when it was taken, can expose you to a host of other unpredictable issues.  It is definitely not a solution to a problem of poor signal strength, just like just upgrading the firmware.  Doing an informal site survey and knowing the actual coverage of  access points is a good and predictable place to start.  After that, it can be determined if the problem is the client not being able to "see" the access point, but first seeing if the infrastructure is performing like it should is a legitimate first step.



  • 9.  RE: Extremely Poor Signal Strength

    Posted Dec 21, 2019 12:47 PM

    In order to have an approximate thought of how to properly place the AP's, and since you already have a MAP, please use the Aruba VisualRF Planner (even though it is a discountinued product, it is still available for download and very useful), which is for free and can be downloaded under https://support.arubanetworks.com/DownloadSoftware/tabid/75/DMXModule/510/EntryId/4830/Default.aspx

     

    With that, you can approximately know where to place your AP's and how many AP's you really need. 



  • 10.  RE: Extremely Poor Signal Strength

    Posted Dec 21, 2019 01:12 PM

    @shpat wrote:

    In order to have an approximate thought of how to properly place the AP's, and since you already have a MAP, please use the Aruba VisualRF Planner (even though it is a discountinued product, it is still available for download and very useful), which is for free and can be downloaded under https://support.arubanetworks.com/DownloadSoftware/tabid/75/DMXModule/510/EntryId/4830/Default.aspx

     

    With that, you can approximately know where to place your AP's and how many AP's you really need. 


    Before access points are deployed, a predictive survey would help, but how would that help AFTER access points are deployed, like in the Op's circumstance?



  • 11.  RE: Extremely Poor Signal Strength

    Posted Dec 22, 2019 05:10 AM

    i assume that the a predicitve survey can tell where the AP should'ev been placed. Also, it can show if they will need to add additional APs or just re-position them properly. 

    It also varies if the they want to have coverage driven design or capacity driven design. With VisualRF, they can have an approximate round-about of how many APs they would need to add or reposition for both scenarios. 



  • 12.  RE: Extremely Poor Signal Strength

    Posted Dec 22, 2019 05:20 AM

    That is good information.  

     

    This thread is 6 months old, so closing it.