SM unable to see 450M AP with clear LOS, but can see adjacent sectors

Earlier today, one of our techs experienced a strange issue with one of our 450M APs (Running 15.1.3 firmware).  With clear LOS to the access point, the only APs that showed up on the evaluation were 2 other sectors on the same tower.  One of them was running on the same frequency, pointing the opposite direction (All sectors on the tower are GPS synced).  After trying multiple SMs with no success, we rebooted the AP, and the radio was able to see and connect to it, but 15 minutes later it lost the link again, and the AP disappeared from the AP Evaluation.  Our tech tried rescanning, and after a few tries the AP finally showed up again, and it has kept the link with no issue.

Has anybody experienced this, or know what may have caused it?

Could the "Adjacent Channel Support" option have anything to do with this?  We do not currently have it enabled, and our tech was installing a 450b SM.  I had never noticed this option before, how important is it to have it enabled when running ABAB frequency reuse?

15.1.3 is pretty old at this point. It’s highly recommend you use 16.0.1 on AP’s and SM’s. The Adjacent channel support option on the AP should be left disabled, although it has no bearing on if an SM can see an AP or not. All it does is when enabled, reduces max SM transmit power to 23dBm. This feature will possibly be removed in the future because it doesn’t really matter.

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Ah, thank you for the clarification.  We're impending an update to 16.0.1, so we will be up to date within a week or so.


There were also some improvements made to sync processing on 450m in 16.0 and later, which may have been contributing to the issues you saw.

Did you happen to have Autosync + Free Run enabled, or just Autosync? The 450m has a slightly higher tendency to drift after a sync loss than older hardware, so having solid sync when doing frequency reuse is important.


The AP has AutoSync + Free Run enabled.  This has only occured the one time AFAIK, so hopefully it won't come up again, especially since we are upgrading to 16.0.1

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