CBRS APs randomly stop broadcasting with CBRS error

We are seeing a CBRS error on occasion that is causing an AP to stop broadcasting with a Grant Terminated message. Rebooting the AP brings it back up and allows customers to reconnect. We have seen this maybe 5-6 times over the past few months, on different APs. We do not have PAL and are using GAA, SAS is Federated. We are on firmware but were seeing it on 20.2.1 as well. Is anyone else experiencing this issue?

CBRS Log at the time of the issue

CBRS Log after a reboot

Why is your radio’s system clock off by over 2 years and 2 months?


NTP issues with the site.

So CBRS relies heavily on time/date related things happening accurately between the radio and the SAS. I’d strongly suggest that you try to get this fixed and possibly try release 21 as there are a number of CBRS related fixes.

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I second this. NTP is critical with CBRS.

OK, we will focus on getting the NTP issue corrected and go from there. Thank you!

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We did put a fix in 21.1 BETA-1 to help this scenario as well.

CPY-16631 - Move CBRS heartbeat timing to relative time instead of absolute time.

This fix will prevent UNSYNC 502 terminations for CBRS operators that have an AP with a clock that gets out of sync with SAS UTC time. This is especially helpful for operators with unstable NTP servers.