This very likely has to do with something called near-field/far-field
[Wikipedia]. If you have a barrier, like a concrete wall you can get weird propagation of the radio signals. From that page, the far-field should start roughly 2 wavelengths from the antenna, where the wavelength for 2.4GHz is something like 23 cm, which is just under a foot for people in the US. From that perspective, 2 ft of distance should be enough; add some margin and you may end up at your 5 ft. Further, if you are deploying an AP close to the outside wall, and you assume the coverage is a kind of circle, you 'throw away' half of your coverage, and putting the AP closer to the center of the building in most cases will bring the AP closer to the clients as well resulting in stronger signals.
There may be other reasons that I'm not aware of, but this one can be one reason.
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Herman Robers
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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.
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Original Message:
Sent: Feb 08, 2021 09:44 AM
From: Alex Holian
Subject: AP Perimeter Layout
Hi,
At work it's being drilled into us to keep APs a minimum of 5' off the walls when designing a new site. I get it if deploying on the ground floor but why do I have to keep an AP 5' away from the perimeter when designing floors in a high rise building? The signal will never propagate to the parking lot if the AP is on the 25th floor.
Thanks!
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Alex Holian
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