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PrismStation advantages in the real world

by a week ago - last edited Sunday

Since Robert posted about the new PrismStation recently - https://community.ubnt.com/t5/Ubiquiti-Announcements-and-News/Filtering-in-3-Domains-Why-PrismStatio...  -  I thought I would put this up about the advantages we're seeing with them.

PrismStations.jpg

This is a group of 3 PrismStations up for testing, with an additional IsoStationAC - more on that later.    This actual group of radios in this configuration will be going up at a local public venue soon - a raceway where they get over 10,000 people on site on busy weekends.   It's a major relay and broadcast site for us, and we also use it for testing out things.

The PrismStations (the 3 upper units on the pole) each have a different horn attached - the 60 degree sector, the 45 degree horn and the 30 degrtee horn (top down).   The IsoStation AC has the 90 degree horn on it.

 

But what I want to talk about here today is the adjacent channel interference filtering capability of the Prism chip system.   The 4 radios are all running as APs, the PrismStations all GPS sync'd together.   The PrismStations are all running 20MHz channels in UNII-3.   Here is an AirView from the IsoStation and you can see the three channels in use above 5700MHz

ACnonPrism.png

Look at the bottom histogram - you can clearly see the three channels in red.   But see what happens with the PrismStations - 

ACPrism45.png

The channels are almost gone!  This is from the one with the 45 degree horn (which comes with the PrismStation).   Here's the one with the 30 degree horn

ACPrism30.png

These radios are all so close to each other that the effect of the individual horn patterns really doesn't make much difference - they are all in each other's "near field" range - and the power levels on Tx are all the same.   So what we're seeing here is due to the difference in the Prisn chip.   Pretty remarkable.

PrismStation60.png

 

Finally here is the PrismStation with the 90 60 degree sector - note that here we do see even greater isolation because it's pointed 180 degrees away from the others.    It's also not picking up much from a bunch of other radios behind it - I've got a lot of stuff up for testing at any given time...

 

Bottom line?   Everything Robert and others are saying about the benefits of the PrismStation is real.   We're planning to use them everywhere we can - we've already  been converting a lot of our older APs with RocketM radios to Rocket-AC Prisms, and this will just accelerate that process.

Jim

" How can anyone trust Scientists? If new evidence comes along, they change their minds! " Politician's joke (sort of...)

"Humans are allergic to change..They love to say, ‘We’ve always done it this way.’ I try to fight that. "Admiral Grace Hopper, USN, Computer Scientist
Comments
by
a week ago - last edited a week ago

very Nice Eejimm. So where can one buy the Prismstations? Ive looked around and can find them Looking for the 90 degree antennas to go with them too. You got a source?

 

by
a week ago

Yeah, rfelements rocks! Man Happy

by
a week ago

Nice setup! Where'd you get the alignment brackets?

by
a week ago

The mounts come with the radios now - 

PrismStationInBox.jpg

Jim

by
a week ago

Hi

It's really crazy and I'm looking forward to getting some up

But there is not much gain on them, so how far can you put CPE on

And can you use a prism station like CPE or is it stupid

 

Regards Flemming 

 

by
a week ago

@vicent_nb1these are not rfelements. These are pure UBNT. Ubnt Banana

by
a week ago

Does the mount have the possibility to let you mount the prism station directly to a wall or is it mainly just poll mount?

by
a week ago

Are the only Prismstation AC units currently available the ones in the Beta Store, or are they also in general distribution? If so, are the Prismstation AC in the Beta store an even newer revision?

 

Very happy to see UBNT going with those real mounting brackets. The plumbers straps they have bundled wtih a bunch of their low-end product always felt cheap. The brackets they have in the box in that photo look really great, and thank god it's made of metal.

 

I'm going to have to order a pair or two of Prismstation ACs and look for a reason to throw up a point to point bridge and see how well they work.

by
a week ago

Can we order mounts for those we have gotten already without mounts ?

by
a week ago

Hi

 

@eejimm You first say the prismstations are 60,45 and 30 degree and the isostation is 90 degree. In the last image you have a 90 degree prismstation? You mean the 60 one, right?

 

Also I think it is not really fair to compare more narrow prismstations to a wider isostation, of course it will pick up more surrounding interference. To make a fair comparison you should use the same antenna pointing the same direction.

And I think the result is showing the directivity of the antennas more then the quality of the wifi chip, especially since (I might be wrong here?) the airview feature uses its own secondary wifi chip and not the primary prism one. So I think it might even be exactly the same chip doing this in both isostation and prismstation.

Another reason can be that Prismstation might have better shielded electronic too so that it will not pick up interference from the back side very easily, simply because because it costs more they can afford that.

 

Kind regards

David