Looking for an AP with High Gain antennas for a small elevation for a multi-story structure

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Looking at the 350 AP and trying to shink the vertical lobes and coverage to about 9 feet to 12 feet for multi-story school with concrete floors. Would the 4 dbi antenna be considered a high gain antenna?

Would I have better control over the vertical RF with the 350 then I do with the 330?

Aerohive AP350 articulated indoor antenna kit (3x2.4Ghz 4dBi and 3x5Ghz 4dBi antennas)

Currently we have the 330s and there is quite a bit of bleed through the floors above and below

Cheers
A
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Andrew MacTaggart, Champ

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Posted 5 years ago

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Crowdie, Champ

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With an AP350 you can utilise high-gain antennas, which you cannot do with the AP330. The AP330 has internal omni-directional antennas that cannot be changed.

With omni-directional antennas the higher the gain the flatter the vertical signal propagation. Think of the omni-directional antenna's signal propagation as being a balloon. The higher the gain on the antenna the more force is being applied from above and below on the balloon. This results in the balloon's shape getting flatter. So a higher gain omni-directional antenna would, in theory, have less bleed through into other floors and provide more coverage on the floor it is installed on.

With external antennas you can get diagrams of their horizontal and vertical signal propagation. Add some to the quoted signal propagation angles as they are always higher than quoted but you should be able to find a suitable external antenna this way.

When you are designing a wireless network on a multi-floor site one of the first things you do is determine what is the maximum transmit power you can use without bleeding through to other floors and causing interference issues. With a large number of my multi-floor sites I have found this level with the 2.4 GHz radio to be around 11 dBm (AP330 access point).

By combining a higher gain external antenna with a reduced transmit power you should be able to limit the vertical signal propagation. You won't be able to completely restrict it but a wireless client on floor x shouldn't associate to an extremely weak signal from floor y when there is a much stronger signal from floor x.

Be very careful with multi-floor sites that you don't design each floor in isolation and then try to bolt all the floors together for a building design. An access point on floor x can, and commonly will, adversely affect an access point on floor y. This is especially true if you have an access point on one floor directly, or most directly, above another access point on the floor below.
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Andrew MacTaggart, Champ

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Thanks Crowdie

I will see if I can get a trial of the 350 AP.

Cheers
A