Bad ePMP 3000 Experience

Looking for some feedback here.  We recently swapped out a ePMP 2K radio that has 35 users on it with a ePMP 3000 AP using the same antenna - an RF Elements horn (not 4x4 obviously).

All signal levels got 3-10db worse across the board.  The ePMP2K was previously doing ~60Mbps at peak, and now is only able to do ~30Mbps (presumably because of the poor CPE signal levels).

Is this because of the antenna that we are using (the RFE horn)?  What else could be causing this?  All AP and CPE are running 4.4-FINAL.

We also noticed that our SNMP monitors which poll for interface traffic are now inverted:

You can see here that inbound/outbound flipped once the ePMP 2K AP was replaced with a 3K AP.

It's probably because of your antenna swap. If you swapped the radio onto the same antenna, you should have the same signal levels if power levels are the same.

What exact horn model did you go with? The ePMP sectors are rated for 17db at 90 degrees with -3 db rolloff.

If you went with a 90 degree symmetrical horn, the gain is only 9.5db with a -6 db rolloff so much worse signal.

This is very simple math so figure out what your sector gain was and true beamwidth and compare it to the horn to find your missing signal.

Sorry - my original post was not clear.. I have edited it.

We did not swap the antenna.  This horn (RF Elements Professional Series 30deg) was connected to the ePMP 2K with good results.  I'm wondering if we don't need to connect a dummy load to the radio's unused ports.  We're also going to try and stack another horn on top of it which is connected to the other two ports on the radio.

Ok so same horn. This means you’re using a connectorized horn, not the twist port because one doesn’t exist for 3k?

Can you put in a 3k Lite which is a 2x2 radio? I’m not sure if 3k is supported with only 2 of 4 ports connected.

Hopefully cambium chimes in.

Correct - this is the connectorized "pro" series horn.  


Don't have any 3KL's in stock, but we're going to try connecting a second horn to the radio.

I think we're also going to try to use these with the new asymmetrical horns:


https://www.ispsupplies.com/RF-Elements-TPA-SMA

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@JoshB wrote:

...we're going to try connecting a second horn to the radio.


OK, cool.  I know there are a number of people (including me) interested in how well this would work.  I do know that Cambium has said that the MU-mimo magic kinda needs to know a lot of exact info about, and be tuned for the antenna - but it would be very interesting to know how well the two horns work for you.  :) 


@ninedd wrote:

@JoshB wrote:

...we're going to try connecting a second horn to the radio.


OK, cool.  I know there are a number of people (including me) interested in how well this would work.  I do know that Cambium has said that the MU-mimo magic kinda needs to know a lot of exact info about, and be tuned for the antenna - but it would be very interesting to know how well the two horns work for you.  :) 


Cambium is designing an OEM horn antenna for the e3k that I think is designed for MU-MIMO. They're beta testing it right now. I don't have very much info on it as I'm not involved in the beta.

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Oh - nice!  I hope they have narrow beamwidth options (30deg?).

Thnks sir, 

I'll try the test first