Regarding linking two separate ePMP links

Just want to make sure all my ducks are in a row and maybe I'll learn something...

Now keep in mind I didn't make the decisions on the purchases or the plan so just trying to make do with it.

So we got 4 integrated ePMP units, updated with the latest software and ready to go.

There's a 20m tower out in the middle of nowhere, just imagine up top there is 2 ptp800's pointing at 90 degrees, the tower is between two buildings both less than 1km away, one at 0 degrees which has no current link and we will put a epmp on its roof pointing at the tower, on the tower is already a ptp650 link down to the second building at 180 degrees. The ptp650 on the building is attached to your typical hockeystick.

Now we can't use that 650 link, for whatever ridiculous stupid reasons,  but the plan as I'm told is to utilize that same hockeystick for the epmp, so the ePMP will be just 500mm above that ptp650 and pointing to the tower somewhere below the 800's on top but below the ptp650.

We have a separate network switch down in the comms hut to link the two ePMP's on the tower, is that necessary? you can't just plug a cable between two power injectors data ports?

Could any of this interfer with the 800's? i think not but worth asking.

So the ePMP on the hockey stick just 500mm above the ptp650, a problem?

Two ePMP's on the tower, almost back to back pointing in opposite directions & unsycnchronised, a problem?

I plan to initially connect each epmp link separate as AP & SM (Ap on building to SM on tower, AP on tower to SM at buidling) to see what channels they select, but will then switch them over to ePTP master and slaves and set the channels with atleast a 2 channel gap between them.

Will set ul/dl to flexible, use MAC filtering, I don't think freq. reuse is of any use but perhaps carrier sense?

and thats all i can think of, any and all opinions appreciated...

Hello Paulau,

The ePMP units will not cause any interference with the ptp 800. The ptp 800 is a split mount licenced link operatiing in licensed frequencies (6g, 11g,18, 23 etc) so you wil not have any issues with ePMP in 2.4 or 5g, mount right next to them if you like.  Now on the other hand, the ptp 650 is a bully in 5ghz, it runs on really high power and definitely can cause interference with a 5ghz ePMP. Are you planning on running these ePMP in 2.4 or 5g? If you are running in 5ghz I would stay as far away from the 650 frequencies. As far as you switch question, just a preference thing. Hope that helps a little.

the ePMPs say 5ghz right on the box, so as far as I know I can't just switch it over to 2.4ghz?

So i guess its just a matter of trying it to then...

Not being a radio expert I thought two links close togethor may cause issues regardless of freq/channel, i'm going to assume the two ePMP links can use the same freq/channel without concern since they are pointing away from each other, kinda like how a cluster re-uses freq/channel.


Found some interesting reading....

1 Like

Yes very good reads indeed. I PM'd you, I can send you all of that in PDF along with some support docs on ePMP etc.