RE: Troubleshooting test basestation connection issue during certification

Håkon Alseth — Tue, 14 Feb 2023 12:21:57 GMT

Hi,

Unfortunately, the modem traces (*.bin files) were empty, so I'll have to give directions based on the .txt logs.

at_client_1.txt shows:

...
+CEREG: 2,"C364","01E15B08",9
+CNEC_EMM: 15
+CEREG: 2,"C364","01E15B08",9,0,15
...

EMM return code of 15 means that you're not allowed to connect to the specific network:

Cause #15 – No suitable cells in tracking area

      This EMM cause is sent to the UE if it requests service, or if the network initiates a detach request, in a tracking area where the UE, by subscription, is not allowed to operate, but when it should find another allowed tracking area or location area in the same PLMN or an equivalent PLMN.

NOTE 3:  Cause #15 and cause #12 differ in the fact that cause #12 does not trigger the UE to search for another allowed tracking area on the same PLMN.

The CellID here is different from what is shown in the other logs:

+CEREG: 2,"C2FA","002E7F67",9
▸[MODEM] Searching for networks
▸[MODEM] LTE cell changed: Cell ID: 3047271, Tracking area: 49914
▸[MODEM] LTE mode updated: NB-IoT

This indicates that the nRF9160 is trying to connect to actual live networks in your area, and not the tester network.

Without any logs from the CMW-500, it is hard to say what specifically is wrong here, but it all points to incorrect configuration on the tester itself.

Kind regards,

Håkon