nRF9160, mfw 1.3.5, CEREG with rejection, how could the PLMN be determined?

[Achim Kraus]

Currently the nRF9160 reports with a network rejection with:

+CEREG: 2,"67B9","01CC2B03",7,0,15

That contains the tracking area and cell ID. But in many cases it would be very interesting, which network operator has rejected the registration.

In the past week quite a lot of user have been surprised by terminated connectivity. With the PLMN it would be easier to check and analyze the root cause.

Is it possible to get the PLMN for the rejected registration?

[Håkon Alseth]

Hi,

 

Unfortunately, it is not possible to get PLMN directly as a notification.

One can read the PLMN via at commands such as AT+COPS? / AT%XMONITOR, but none of these are available as a notification.

 

What I can recommend is to query AT%XMONITOR or AT+COPS when you receive a AT+CEREG notification.

 

Kind regards,

Håkon

[Achim Kraus]

Thanks!

I'm wondering, if you have tested the proposals.

In my experience, AT%XMONITOR doesn't report the PLMN until you registered, so in case of rejection, that doesn't work.

AT+COPS? lists only the PLMN and mode (7 or 9 for LTE-M or NB-IoT), but no relation to the rejected TAC, so also doesn't work.

[Håkon Alseth]

Hi,

 

My apologies for my misinformation here, you are correct and my former response is not. I dug deeper into this, and it is not possible to get all this info. I will report this internally as a feature request.

 

Kind regards,

Håkon

[Achim Kraus]

Thanks!

I also searched the web to see, if there is any relation (table?) for TAC/LAC to the PLMN. I wasn't successful, but maybe there is something as that.

[Håkon Alseth]

Hi,

 

Unfortunately, there is no overall open database that has these lookups available. You can have a look at opencellid and similar projects, but they are not always up-to-date.

 

Kind regards,

Håkon