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stefaantje
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Antenna gain of wAP ac / wAP R ac / alternative

Wed Jun 24, 2020 11:10 pm

I have an application where I need an Outdoor Access Point (30m by 30m open space, AP can only be mounted at the far end of the property, clear LoS).
I'm wondering whether I will get good enough performance on 5 GHz when using the wAP ac.

From the spec sheet, I see its omni antennas only have 2 dBi gain.
I don't know if the (mostly low-end) 5 GHz devices will have sufficient power to reach such a (relatively weak) antenna from 30m...
I want to keep transmit power from the AP low enough, to avoid penetration in the neighbouring buildings.

> Would it make sense to make the small jump to the wAP R ac, as this one seems to have (only slightly stronger) 2,5 dBi antennas? (I don't need the LTE)
It also sports more recent & more powerful chips, don't know if that is of much importance?

> Any other alternatives?
The Omnitik 5 ac would be an uber-AP, due to its 7,5 dBI antennas, but I'd really like some 2.4 GHz support in the AP for some occasional, really old devices...
An indoor unit with a single outdoor antenna would also be possible, but I can't seem to find such an offering in the MT catalogue.


Thansk for your input.
Stefaan
 
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bpwl
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Re: Antenna gain of wAP ac / wAP R ac / alternative

Sat Jun 27, 2020 7:06 pm

Just my thoughts. (Installed SXT sa5 ac, SXTsq 5 ac, having an Omnitik 5 ac , considering mANTbox 15s)

- double distance needs 6 dB more. To have the same signal at 20m instead of 10m you need +6dB, for 40m +12dB, for 80m +18dB. So 0.5 dBi is not significant.
- the TXpower will be lowered by the same amount as the antenna gain, to maintain the same legal EIRP level. But the receiving sensitivity wil be improved by the number of dBi of the antenna
(so you will receive your weak devices). Stronger AP? The regulation for the region is mostly the limiting factor.
- consider a sector antenna, to not receive the whole neighborhood. (That is one of the reasons why I will replace the Omnitik with a mANTbox 15s.)
- indoor unit with external antenna? Sometimes installing the antenna cable is more complex than installing a PoE UTP cable. (So I prefer mANTbox over mANT antenna)
- check mANT 15s antenna for related devices (NetMetal, Netbox, Basebox) if you still want separation.
- Since 802.11n we use 2 antenna for spatial stream (double speed)
- Check Groove device.
 
anav
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Re: Antenna gain of wAP ac / wAP R ac / alternative

Sat Jun 27, 2020 7:34 pm

Your description is lacking.
Can you provide a diagram of pertinent locations and distances and how are you going to power the device at the far end??
It sounds like an omni device in the centre of the area would be ideal (possible?)
If not agree that a sector antenna coupled with an outdoor device (no antenna wire) would be best with power/gain on antenna tuned (down) to what is required for the area.
I'd rather manage rats than software. Follow my advice at your own risk! (Sob & mkx forced me to write that!)
 
stefaantje
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Re: Antenna gain of wAP ac / wAP R ac / alternative

Sun Jun 28, 2020 10:51 pm

I added a somewhat detailed plan of the layout.
Image

In the green area's good signal is required. (note: close to 100/20 Mbps on 5 GHz is the target, which is the actual wired speed.
In the upper right corner, I have ethernet cable & power present inside the (brick walled) garage.

I tend to prefer an omnidirection signal on the outside of the garage, allowing some signal to penetrate inside the garage.
An AP mounted inside the garage would be an option, but I really favour outdoor signal strength over signal strength inside the garage.

Throughout the garden, I pick up zero 5 GHz signals from the neighbours, and only a few weak 2.4 GHz signals.
 
anav
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Re: Antenna gain of wAP ac / wAP R ac / alternative

Mon Jun 29, 2020 7:00 pm

I like the idea of a WAPAC place outside facing the garden (in the middle of the garage above door height etc.).
Simplest and decent wifi specs.

I also like the idea of a combo unit (Sector approach) from the corner of the garage aiming at the house and garden, with gain/pwr tuned down to what is needed.
The netmetalAC2 looks like one of the few items that provides BOTH 2.4 and 5ghz at the same time.
One has to provide ones own attenna(e). You could try it with two of the ($9 HGO omnis from MT) or go big with sector.
Future Growth potential, with Sim Card for LTE backup, as well as fibre line input.

What I dont know is how sector antennas work? Do they use both connectors? If not consider an omni for the 2ghz on one and a sector 90 or 120 on the other
(if a sector antenna need both find a combo antenna 90 or 120 degrees)
I'd rather manage rats than software. Follow my advice at your own risk! (Sob & mkx forced me to write that!)

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