AP too close?

[apostolakisl]

Not ISY related at all.  Here is my issue.  I have Unifi stuff.  I have an AP that is maybe 5 feet away from a wifi camera.  I have another AP that is about 50 feet and 4 walls away.  The wifi camera refuses to use the one that is straight line of sight 5 feet away.  It ends up working poorly as far as the one 50 feet away.  I tried physically swapping the two AP's and still, it picks the one far away.  If I move closer to the far away one, it sends photos ASAP.  WWWWWWHHHHHHYYYY!!!!  The AP's are both the same AC Pro models.  Other things connect fine to both AP's (but none of those things are 5 feet away).

[TrojanHorse]

I’m not an expert but I think that’s possible. The APs propagate their signal in a certain pattern. I saw the diagram previously - you may be able to find it. But IIRC they’re meant to propagate the signal downward, not so much outward. So ceiling mount is best.

How is the AP positioned relative to the camera? Can you try just changing its orientation to see if it works better? If the AP was on the same plane (e.g wall) as the camera or off to the side of it at the same height or above and If they were close I could see having trouble.

An option in the UniFi controller I believe is to exclude a device from a certain AP, so you could do that and force it to connect to the close one during testing and after when you get it to work.




Sent from my iPhone using Tapatalk

[markv58]

I have 4 Unifi APs and I never understand why things connect the way they do. If a device is giving me trouble I do a reconnect and usually it will connect to the closest AP.

If you have Airtime Fairness turned on, that can cause some problems.

[mwester]

I recall as a child I had the "privilege" of sitting next to the giant bank of speakers on stage for a school event -- not only was I temporarily deaf by the end of the event, I was completely unable to understand a single word of the speeches made.   It's exactly the same for radio signals when the transmitter is too close to the receiver -- the radio front-end gets overloaded and the distorted waveforms make reception impossible.  Most devices have some form of internal gain control to handle that, but that only works within limits -- and I'd not be surprised if a few feet is too close.

If it has an external antenna, you can try removing it... 

[markv58]

@mwester That makes complete and total sense. Never thought of it that way.

[apostolakisl]

playing around, I changed both 2.4 ghz channels from auto channel to manual and set both to channel 3.  (The camera runs on 2.4ghz)  Now it is picking the closer one and working very well.  Not sure whether both being on the same channel or if channel 3 is a happier place is the reason (neither AP's was on 3 before this).   I'm inclined to leave it alone now.

[larryllix]

56 minutes ago, apostolakisl said:

playing around, I changed both 2.4 ghz channels from auto channel to manual and set both to channel 3.  (The camera runs on 2.4ghz)  Now it is picking the closer one and working very well.  Not sure whether both being on the same channel or if channel 3 is a happier place is the reason (neither AP's was on 3 before this).   I'm inclined to leave it alone now.

I found my 5GHz working much better once I turned down the amplitude of my 2.4GHz WiFi sharing the same antennae. After several rounds of decreasing the signal to about 10% of the original gain my wife's iPad worked anywhere in the house instead of not quite across the 28 foot wide room span, on the 5GHz band.

However, I found a few items wouldn't reconnect after a WiFi break for any reason, and my neighbour's WiFi, a few hundred feet away was overpowering my channel's amplitude on signal detecting apps, in my own home. I analysed the channels in usage around the neighbourhood and found a hole between the usual default channels 1, 6 and 11. Things worked well again until the next weekend when the same neighbour's WiFi switched to my channel selection and clobbered my signals again.

I surmised that he wasn't purposely doing it, and that his router was set to reboot each Saturday night. Now figuring that the automatic channel select only did a power up channel selection, and stuck with it hell or high water, until the next reboot, I understood what was happening. I then increased my WiFi output power again and chose another blank spot in the 2.4GHz band. I haven't had the problem since. 

Look for free android apps to identify every WiFi channel used and find a larger channel opening and leave it on manual selection. It works better without as many surprises.

The other thing I have learned is most 5GHz WiFi frequencies share with radar frequencies. The spec'd WiFi agreement makes routers immediately shut down and change channels if they hear a radar signal. This causes people living under flight paths lots of grief with channel dropout on 5GHz.

[apostolakisl]

3 hours ago, larryllix said:

I found my 5GHz working much better once I turned down the amplitude of my 2.4GHz WiFi sharing the same antennae. After several rounds of decreasing the signal to about 10% of the original gain my wife's iPad worked anywhere in the house instead of not quite across the 28 foot wide room span, on the 5GHz band.

However, I found a few items wouldn't reconnect after a WiFi break for any reason, and my neighbour's WiFi, a few hundred feet away was overpowering my channel's amplitude on signal detecting apps, in my own home. I analysed the channels in usage around the neighbourhood and found a hole between the usual default channels 1, 6 and 11. Things worked well again until the next weekend when the same neighbour's WiFi switched to my channel selection and clobbered my signals again.

I surmised that he wasn't purposely doing it, and that his router was set to reboot each Saturday night. Now figuring that the automatic channel select only did a power up channel selection, and stuck with it hell or high water, until the next reboot, I understood what was happening. I then increased my WiFi output power again and chose another blank spot in the 2.4GHz band. I haven't had the problem since. 

Look for free android apps to identify every WiFi channel used and find a larger channel opening and leave it on manual selection. It works better without as many surprises.

The other thing I have learned is most 5GHz WiFi frequencies share with radar frequencies. The spec'd WiFi agreement makes routers immediately shut down and change channels if they hear a radar signal. This causes people living under flight paths lots of grief with channel dropout on 5GHz.

The unifi stuff has a feature called "insights".  It gives you lots of info about all sorts of things, like neighboring wifi broadcasts, so no need for a phone app.  I very surprised to see that I am picking up wifi from some businesses that are several hundred feet away in a different building.  Anyway, hopefully this keeps working on channel 3.  So far, this is one frustration that I got around to tackling that might be gone.  

A second unrelated frustration that has been driving me nuts is a USB card (actually cards) I installed in my server.  I ended buying 3 different cards because they were all flaky.  Finally, I thought, "this kind of seems like a weak power supply".  Sure enough, the wiring harness had one of the pins slipped back in the socket and was not making contact.  So the usb cards were only getting power from the PCIe slot, or perhaps intermittent power from the power supply.  Things would work for weeks or months, and then get flaky.  Man was that a frustrating one to figure out.

[larryllix]

5 hours ago, apostolakisl said:

The unifi stuff has a feature called "insights".  It gives you lots of info about all sorts of things, like neighboring wifi broadcasts, so no need for a phone app.  I very surprised to see that I am picking up wifi from some businesses that are several hundred feet away in a different building.  Anyway, hopefully this keeps working on channel 3.  So far, this is one frustration that I got around to tackling that might be gone.  

A second unrelated frustration that has been driving me nuts is a USB card (actually cards) I installed in my server.  I ended buying 3 different cards because they were all flaky.  Finally, I thought, "this kind of seems like a weak power supply".  Sure enough, the wiring harness had one of the pins slipped back in the socket and was not making contact.  So the usb cards were only getting power from the PCIe slot, or perhaps intermittent power from the power supply.  Things would work for weeks or months, and then get flaky.  Man was that a frustrating one to figure out.

With the new high speed WiFi specs they take up 4-5 channels of bandwidth, so some channel overlap is almost inevitable. I am quite impressed with the latest WiFi bandwidth at 866 Mbps being faster than wired Ethernet and almost as fast a wired GigaBit Ethernet. Wires are becoming obsolete. I see none of my neighbours use the higher channels on 5GHz. I think older (or cheaper)  routers may not be capable.