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Here's a strange one,

I'm commissioning some Motorola/Symbol MC40 Android scanners in a warehouse environment. They just installed new WiFi APs to cover the warehouse. They seem to work fine, except when standing directly underneath any AP, the WiFi begins cycling between 'Disconnected' and 'Associating' endlessly until you walk several more feet away from the AP.

A deeper look into the logs showed the disconnect event followed by an error on reassociating: "Supplicant Reason Code 1: There is a preferred site: .....39:16:F7 use it" and an "Association denied: error code (104) irrelevant". I walked to another AP and got the same set of errors with a different BSSID. I thought I was onto something, but neither my phone or PC WiFi have any problems standing in the same spot...

This is a strange one on me, but I thought I had enough specific errors and info to come out on top with Google, but got nothing relevant to my issue. Hopefully something here will stand out to someone more experienced and we can get it debugged. Thanks for your help.

sleepisfortheweak
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1 Answers1

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That is the product of the antenna, I think. Even with most omni directional antenna's the wifi signal strength is somewhat doughnut shaped and not completely spherical, causing a blind spot directly above and below the access point:

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Many access points allow you to change the antenna's direction to tune them and others are specifically designed for ceiling mounting.

Your phone and laptop might have better better antennas or better logic causing them to switch to another AP.

HBruijn
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  • Thanks for your quick answer. I thought my phone and PC ruled out a blind spot, but didn't consider they may have connected to another AP. I'll have to check BSSIDs and look closer at signal strength when I'm on-site again. I'll be frustrated if these have roaming issues since multi-AP environments are probably 90% of the market they're used in... – sleepisfortheweak Aug 08 '16 at 23:15