how to change Esim profile for nbiot fall back

[bhanu prakash]

Hi,

I'm using nrf9160custom board using sdk version 2.0.0
our Esim has 2 profiles one is for LTE and another one is for NB-IoT. Present i have tested tested LTE network and its working fine but i need to work on NB-IoT.

i have no idea how to do fallback for LTE to NB-IoT.

our Esim provider given fallback APDU command.

i have refered below document too but i don't have any how to send AT+CSIM command

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fref_at_commands%2FREF%2Fat_commands%2Faccess_uicc%2Faccess_uicc.html

Thank you

[Didrik Rokhaug]

Hi,

Which modem FW version are you using?

Have you tried to just set the system modem to NB-IoT or LTE-M and NB-IoT, to see if the modem handles it automatically?

You can find the documentation on how to send AT commands from the application here: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.3.0/nrfxlib/nrf_modem/doc/at_interface.html

Best regards,

Didrik

[bhanu prakash]

Hi,

Didrik Rokhaug said:

Which modem FW version are you using?

I'm using FW version 1.3.4 

Didrik Rokhaug said:

Have you tried to just set the system modem to NB-IoT or LTE-M and NB-IoT, to see if the modem handles it automatically?

Before we using plastic sim card in that we have implemented he NB-IoT fallback and its working fine but now we are using ESIM instead of plastic sim .Now our ESIM have 2 profiles one is for LTE and another one is NB-IoT. 
so if i need to using NB-IoT fallback first i have to change the profile. so how i can change the ESIM profile?

our Esim providers proved APDU command for fallback. i have tried "AT+CSIM" command for fallback but i don't either it changes or not. how i can i check either it change or not?

if you need i can provide ESIM document for your reference.

Thank you

[Didrik Rokhaug]

bhanu prakash said:

i send at+cops=? command when nRF9160 is in LTE mode.

If you only had LTE-M enabled (%XSYSTEMMODE=1,0,0,0), the modem will only search for LTE-M networks. Regardless of what the SIM card supports.

[bhanu prakash]

Hi,

Didrik Rokhaug said:

If you only had LTE-M enabled (%XSYSTEMMODE=1,0,0,0), the modem will only search for LTE-M networks. Regardless of what the SIM card supports.

i have tried with NB-IoT enable too i that moment i'm got error msg then i got all same networks with mode "9"

+COPS: (1,"","","26202",9),(1,"","","26203",9),(1,"","","26201",9)
+CME ERROR: 521

[Didrik Rokhaug]

bhanu prakash said:

i have tried with NB-IoT enable too

Did you have both modes enabled, or just NB-IoT?

CME error 521 means "PLMN search interrupted, partial results"

[bhanu prakash]

Didrik Rokhaug said:

Did you have both modes enabled, or just NB-IoT?

i enable only NB-IoT mode using command at%xsystemmode=0,1,0,0

[Didrik Rokhaug]

Then only NB-IoT will be searched, so it will not look for any LTE-M networks.

I did some tests with my LTE-M only SIM card (so not the exact same situation as you have, but some of the results might still be relevant).

If I enable only NB-IoT, it would find the local NB-IoT networks. However, if both LTE-M and NB-IoT modes were enabled, it would connect to a LTE-M network (because that is what my SIM card supports), and also only list LTE-M networks. So it appears that AT+COPS=? will only list networks from one mode, even though both modes are enabled.

[bhanu prakash]

Didrik Rokhaug said:

If I enable only NB-IoT, it would find the local NB-IoT networks.

in this case when i search for NB-IoT  if getting error that means my e-sim don't have NB-IoT network right?

How can i enable both LTE & NB-IoT modes as i now "1,0,0,0" is to enable LTE "0,1,0,0" is for NB-IoT
so i need to enable both is have use "AT%XSYSTEMMODE=1,1,0,0" ?

[Didrik Rokhaug]

bhanu prakash said:

in this case when i search for NB-IoT  if getting error that means my e-sim don't have NB-IoT network right?

What error do you get?

I am able to search for NB-IoT networks with my LTE-M-only SIM card, so there shouldn't be any limitations on searching.

bhanu prakash said:

How can i enable both LTE & NB-IoT modes as i now "1,0,0,0" is to enable LTE "0,1,0,0" is for NB-IoT
so i need to enable both is have use "AT%XSYSTEMMODE=1,1,0,0" ?

Yes, AT%XSYSTEMMODE=1,1,0,0 will enable both LTE-M and NB-IoT, with no specific priority to either mode.

You can find the documentation for the %XSYSTEMMODE command here: https://infocenter.nordicsemi.com/topic/ref_at_commands/REF/at_commands/mob_termination_ctrl_status/xsystemmode_set.html