nRF9160 with NB-IoT in Switzerland

[Chraebs]

Hi

I'd like to use NB-IoT in Switzerland.

According to https://www.gsma.com/iot/mobile-iot-commercial-launches/ there is support for both LTE-M and NB-IoT in Switzerland.

Also, when looking at the AT+CEREG notifications I get on my devkit running the at_client example, it indicates <AcT> 9 which means "E-UTRAN NB-S1".

However, the modem (v1.3.0) fails to complete registering at the network cell.

2021-07-19T14:38:54.033Z DEBUG modem << +CEREG: 2,"EBF0","0114A96A",9,0,0,"11100000","11100000"
2021-07-19T14:39:00.143Z DEBUG modem << %CESQ: 24,1,2,0
2021-07-19T14:39:02.968Z DEBUG modem << %CESQ: 19,0,0,0
2021-07-19T14:39:06.927Z DEBUG modem << %CESQ: 14,0,0,0
2021-07-19T14:39:13.187Z DEBUG modem << %CESQ: 24,1,4,0
2021-07-19T14:39:13.265Z DEBUG modem << +CEREG: 2,"EBF0","0112A06B",9,0,0,"11100000","11100000"
2021-07-19T14:39:15.983Z DEBUG modem << %CESQ: 25,1,9,1
2021-07-19T14:39:18.535Z DEBUG modem << %CESQ: 14,0,0,0
2021-07-19T14:39:19.247Z DEBUG modem << %CESQ: 21,1,0,0
2021-07-19T14:39:22.468Z DEBUG modem << %CESQ: 27,1,7,1
2021-07-19T14:39:22.575Z DEBUG modem << +CEREG: 2,"ECB8","00772B69",9,0,0,"11100000","11100000"
2021-07-19T14:39:23.662Z DEBUG modem << %CESQ: 28,1,13,1
2021-07-19T14:39:25.264Z DEBUG modem << %CESQ: 25,1,6,0
2021-07-19T14:39:25.464Z DEBUG modem << %CESQ: 21,1,0,0
2021-07-19T14:39:26.287Z DEBUG modem << %CESQ: 25,1,6,0
2021-07-19T14:39:26.687Z DEBUG modem << %CESQ: 28,1,11,1
2021-07-19T14:39:27.280Z DEBUG modem << +CNEC_EMM: 15
2021-07-19T14:39:27.337Z DEBUG modem << +CEREG: 4,"ECB8","00772B69",9,0,15,"11100000","11100000"

I tested this both with a "roaming" SIM (IMSI 20408...) and a "native" SIM (IMSI 22802).

I also found that iBasis SIM (IMSI 20408) notes a "N/A" for Switzerland https://www.nordicsemi.com/-/media/Software-and-other-downloads/3rd-party/iBasis-simplified-coverage-map-for-web.pdf?la=en&hash=CA7DBF400243D8A7A7BDA94873B50E73C26B4FAC.

Questions:

* Has anyone ever used NB-IoT in Switzerland

* Is my interpretation right, that <AcT> 9 means that the cell supports both LTE-M and NB-IoT, and <AcT> 7 means only LTE-M is supported. Or what is the exact meaning of it?

[Hakon]

Hello,

there is no coverage for NB-IoT for iBasis in Switzerland yet. You will need to contact iBasis or the local carrier if you need more details.

[Chraebs]

Ok thanks Hakon this corresponds to what I figured out in the meantime. It seems that for the iBasis SIM roaming is not allowed for NB-IoT in Switzerland yet (roaming in Switzerland with iBasis SIM is only available for LTE M1).

I checked with the local network providers. Even their own regular SIM cards do not support NB-IoT but only some dedicated IoT SIM cards. For those, they claim having roaming arrangements for most parts of Europe and world wide (but less than for LTE M1).