We use nRF9160 with our board (with Serial LTE Modem 1.9.1).
Now we are at the production stage and we have more cases when we cannot get access to the mobile network.
We are talking even about situations when the device is in a static position, and access to the network can be getting only one of several iterations.
AT+CEREG=5
OK
AT+CFUN?
+CFUN: 0
OK
AT+CFUN=1
OK
+CEREG: 2,"1DC5","001D320D",7
AT+CEREG?
+CEREG: 5,2,"1DC5","001D320D",7
OK
On the command to enable the full functional mod (AT + CFUN = 1), we expect to receive a response of the form + CEREG: 5,5, "1DC5", "001CF20C", 7,,, "11100000", "11100000" but this does not happen during allocated 5 seconds, rechecking the status of the network connection produces a result of the form:
+CEREG: 5,2,"1DC5","001D320D",7 (– Not registered, but UE is currently trying to attach or searching an operator to register to).
Rebooting the nRF9160 (which we use as a last resort in cases where we do not get the expected result) also does not always give a positive result.
Rechecking the network status after some time also does not give the expected result.
It looks rather strange considering that the device is not moving, and periodically successfully goes online (with all subsequent work logic).
What could be the cause of such a problem?
