Best mounting orientation for 7782 to cover this area

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  • Updated 2 years ago
I'm trying to use a 7782 on my balcony to provide wifi coverage of my apartment's pool area. The balcony is 4th story, around 150ft high, and the pool area is around 300ft by 300ft rectangular.

I know ideally I should be using a 7782-S or another 120-by-30 sectorized antenna angled diagonally down, but that'll be "version 2" of this project later down the road :)


So, using an omni 7782, if my goal is to cover the pool area below, is the best mounting orientation to mount it flush with the back of the AP on the metal railing, or use the dome-down mounting bracket and point the dome down towards the ground? I understand that the signal radiates in a dome shape that's more along the horizontal plane than the vertical plane, which makes it sound like I want to point the dome straight down, but then one half of the AP seems to be broadcasting uselessly into a metal railing at point-blank range.


I've attached a picture. This isn't the exact site, but it's pretty much the same layout:

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John D, AlphaDog

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Posted 2 years ago

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John D, AlphaDog

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I did a little testing and it seems like mounting it against the railing parallel to the building pointing outwards (the left picture) works better than mounting it dome-down pointing at the ground (right picture).

At the same time, wow, the "back side" of the 7782 really has poor reach. The difference is way more noticeable than the front of dome vs back of dome difference on the 7982/R700. I had to reposition my indoor AP's to form a mesh link above 50mbit.
(Edited)
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Eizens Putnins

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Hi, John,
It is completely understandable that AP backside has low signal -- in outdoor APs there is a metal plate under the antenna, to provide shielding actually. Also it would make sense not to use mesh, but connect a cable -- you need cable for PoE anyway, so why not to connect Ethernet?

Optimal angle is probably somewhere about 45-60 degrees -- directing the best signal axe to about the 3/4 of maximal area distance. But difference with horizontal position must be just 2-3 db at most.  There is much more difference, if you use AP with directional antenna (ZF7782-S or N for example), than mounting angle must be calculated precisely.
What is more important -- don't mount AP directly to metal railing, use some additional mounting parts, try to do it so the  distance between AP dome and any metal parts is at least 40-50 cm (if it is more, than it's even better). This not so much affects Tx, but can hurt Rx seriously.  It depends on railing construction, of cause, the worst case is the complete metal surface. From this point of view mounting AP vertically may be better, even so antenna diagram is than used less efficiently.

I have had similar setup (with horizontally mounted  ZF7762 on the third floor), covering ~100x100m parking lot and it worked  well, signal was usable (-74dbm) even  in the cafe on opposite side of the street (indoor), and, of cause, outdoor signal was better.
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John D, AlphaDog

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Thanks for the detailed response! Your suggestion to use a slightly angled down approach worked great! Slightly better than flat against the railing. I'm observing around 40-50mbit throughout the pool area, with a mesh uplink around 110 down 80 up. Overall I am quite satisfied.

And yes, in the long run I would obviously prefer wiring this in, but I don't have many easy options. There's no Ethernet close to the balcony and I would rather not compromise the seal of any windows or doors to run Ethernet cables outside. I tried using an AV600 power line Ethernet bridge and that was a total joke -- 20mbit!

I know it'll perform better if I don't rely on meshing, but right now the performance is acceptable for me.