Two ePMP Force 180's on the Same Pole Same AP

We have installed two Force 180’s off the same mounting pole. These SM’s are pointing and connected to the same AP. We’re experiencing session drops on one of the modules although line of sight and Fresnel zone clearance is good. We’re seeing spikes in the RSSI up to -23dbm at regular intervals on both of the SM’s. Is there a problem with interference even though we’re GPS sycn’d on our sites? If so, I would of thought that with TDD same AP that the modules would not hear each other.

If the radio is not transmitting, it is listening. Since one SM can not transmit while the other SM is transmitting, it is listening. It will see the RF power of the other SM and vice versa.

Thank you, that makes sense. I’m going to try providing better separation. Unique situation, two house inside of a tree lined property, each want their own services. Had customer’s put in a pole outside of the tree line and trench conduit to each house. Will have to find another way to do this most likely.


Eh, I have one apartment building with 3 F180s mounted on top each other on the same J-pole mount. They are literally almost touching each other and it’s been working like that for… 4 years or so. Several other places with two radios of various models mounted right next to each other. Now, all our stuff is TDD 75/25 Synced. I don’t know have anything running ePMP/Flexible mode so I can’t speak to how the timing works on that.

Doing TDD synced/timed so what if SM-A can hear SM-B TX, when SM B is TX’ing it means the AP isn’t TX’n so there is nothing SM-A needs to hear from the AP. In other words the near by SM’s can’t keep SM-A from hearing anything from the AP that it needs to hear because they will never be transmitting when the AP is talking to SM-A.

If the SM’s were talking to different AP’s then yeah, that would not work at all but as long as they are talking to the same AP it’s fine in my experience.

Ok one is an F300-16. The site they are on was power cycled 4 hours and 54 minutes ago but otherwise they don’t drop session any more/less than any other radio, which is … almost never.

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We have a couple sites that have F180’s on the same pole, never had problems as we are sync’d 50/50.
One site has two on one pole facing separate towers (tower redundancy for a business) and still do not have any issues.

I would take a spectrum scan and see if there is a near channel talker causing issues.

I believe we traced the problem to a faulty SM. 8 to 10dbm difference in signal with the one that is staying in session. Actually the bad sm is hearing an AP (different frequency) to its right on another tower at -65dbm and pointing right at the attended tower is -76dbm. Sounds like an antenna issue, maybe the unit was dropped prior to install, who knows.