We just had the 3rd occurrence of a strange problem on a PMP 450i 900 Omni running 20.0.1. All SM’s will suddenly drop their modulation to 1X/1X and then take around 30 minutes to recover. We suspected a GPS sync issue and the event log does show that GPS sync did drop briefly but recovered.
SM’s were reachable but interface was very slow. Reboot of an individual SM resulted in the SM deregistering and not reconnecting. Reboot of the AP resulted in the same, all SM’s deregistered and did not come back. All are indications of a timing problem.
The AP is not co located with another 450i, nor is there any other 900 in the area. We have another 450i 900 Oming 5+ miles away on the other side of a hill and spectrum anayluizers show that they do not see each other, but we use GPS sync on both AP’s anyway as a precaution. To date, we have not seen any indications of this problem on the other AP.
The AP was reachable and showed it was receiving GPS. We changed to internal sync on the AP but it did not alleviate the problem, nor did a frequency or bandwidth change. In all 3 cases everything eventually recovers on its own after about 30 minutes, returning it previous 8X/8X 8X/7X modulation levels.
After the latest even we were looking at the Sync Status page on the affected AP, it does not appear to be populating as it should. It shows 11 satellites visible and 16 tracked. How it can track more than it can see seems odd. It also shows the tracked SNR as 0 and the DOP fields are blank. The visible satellite signal information is also blank. 45 minutes after everything stabilized the only change on the Sync Status page was it now is tracking 18 of 11 visible satellites.
My first thought is the Packetflux sync source via the UGPS is malfunctioning, but the swap to internal sync didn’t help anything, so to me if the Packetflux was the issue, shouldn’t that have recovered the SM’s? The Packeflux is mounted close to the AP and the AP shows a good connection. .
Since the other 900 450i AP is running the same exact configuration and has not had these issues, one would assume that rules out a software issue…
Anyone encountered this type oif scenario before? Right now we plan on replacing the Packetflux and cable once the weather clears, but since the unit didn’t recover on internal sync, not confident that will actually resolve the issue.