SMs keep dropping out on AP

The SM’s keep dropping out and trying to reregister. This will last for about 10 minutes or more and then work fine for several hours and then do it again. If I reboot during this problem, it works fine right away. RSSI & dBm look fine during this process.

Here is our setup.

2 900MHz AP’s on one tower each facing in opposite directions.
Each AP Vertically separated by about 15 ft. One is about 105 ft and the other is 120ft.
Sectorized Yagi antennas on each AP. 65 degree horizontal beam width.
One AP is on 906 Freg and the other AP is on the 915 Freq. Vertically polarized. I used the spectrum analyzer and 906 & 915 MHz appears to be clear.
NO CMM installed.
5 SMs on each AP.
Each AP is generating its own SYNC pulse.
Color Codes are setup properly.
All SMs are set only on its corresponding AP freq.

The problem seems to happen more often on the AP facing south which is set at 915MHz

Any ideas? It is frustrating.



Had the same problem. What you got is one of three things

Faulty antennae either on the SM or the AP. If you are using cheap Yagis throw them away.

Alignment issue. Make sure you have the best possible signal RSSI and Jitter from the AP side as well as the SM Side.

On Channel Interference from a SCADA system in the area. SCADA system do not transmit all the time they will come up for a few minutes every so often and drive you crazy and then disappear.

Good luck

Thanks for the info.

I suspect it could be the SCADA. But how do I test for that?

Second, if it is the antennae, can you make a recommendation?

I doubt it is the initial alignment unless the antennae’s have sinced moved. I will need to check on that.

Again, thanks for the input.