NRF9160: detecting common SIM card problems

[2PrintBeta]

Hello Nordic Team,

We are currently working on a product with the NRF9160 Soc. If the products has problems connecting to the LTE network, we want to inform the user on what might be the issue.

So now i am looking for ways to find the cause why a network connection might have failed/timedout.

I found that i can check for a correctly inserted SIM card with the AT%%XSIM? command.

Is there also commands to check for other common sim card / network errors ?

I am especiallly looking for ways to detect: 

- SIM card inserted, but SIM card is not activated

- SIM card is actived, but has no data left.

- SIM card has not the correct network type (NB-IoT)

kind regards,

Dominik Wenger

[dejans]

Hi,

SIM card inserted, but SIM card is not activated

To read UICC state you can use AT%XSIM. If you are interested in knowing current network registration status, you can use AT+CEREG command. If modem cannot communicate with SIM card, SIM card status would indicate a failure. Connection to the network should also fail if SIM card is working but does not have valid subscription.

SIM card is actived, but has no data left.

In this case, connection to the network should succeed but no DNS lookup or data transfer would be possible. The error code would be obtained from getaddrinfo.

SIM card has not the correct network type (NB-IoT)

In this case the device would be rejected from the network with specified rejection cause.

Best regards,
Dejan