nRF9160 NB-IoT signal strength polling

RE: nRF9160 NB-IoT signal strength polling

danielClark — Thu, 04 Apr 2019 12:43:30 GMT

Hi Øyvind,

I can confirm that solves the problem. I didn't realise the PSM activates by default. Thank-you very much for the help.

kind regards,

Dan

RE: nRF9160 NB-IoT signal strength polling

Øyvind — Thu, 04 Apr 2019 10:17:36 GMT

Hi Dan,

Thanks for your patience! Our team has found the root cause, and here is their answer:
"Reason to signal loss it that the UE enters to the PSM 30 seconds after attach. PSM is activated in the used SW and the network returns T3324 value as 30 seconds and T3214_ext value as 310 hours. If Customer does not want use PSM then it is recommended to disable PSM by sending AT command AT+CPSMS=0."

Can you please try and verify this solution?

Thanks!

-Øyvind

RE: nRF9160 NB-IoT signal strength polling

Øyvind — Mon, 01 Apr 2019 06:43:31 GMT

Thank you. I have forwarded the modem trace and log file to our internal team and will get back to you as soon as I have an answer.

-Øyvind

RE: nRF9160 NB-IoT signal strength polling

danielClark — Fri, 29 Mar 2019 15:40:37 GMT

Hi Øyvind,

Attached is the trace file.

devzone.nordicsemi.com/.../trace_2D00_2019_2D00_03_2D00_29T15_2D00_04_2D00_49.777Z.bin

kind regards,

Dan

RE: nRF9160 NB-IoT signal strength polling

Øyvind — Wed, 27 Mar 2019 14:13:23 GMT

Thank you, Dan.

Can you also provide a modem trace from your board? Follow these instructions:

Program the hex file zephyr_at_client.hex with this command
nrfjprog.exe --program zephyr_at_client.hex -f nrf91 --sectorerase --verify devzone.nordicsemi.com/.../zephyr_5F00_at_5F00_client.hex
Reset the board.
Install "Trace Collector" in nRF Connect 2.6.2, then open and connect to the nRF91 board.
1. Click "Start capture"
Open LTE Link Monitor and connect to nRF91.
1. Reset the board once more.
2. Enter the AT command AT%XMODEMTRACE=1,2 and click send. Should return OK.
Start AT_client application with AT+CFUN?
In the Trace Collector keep your eyes on the trace size, if the size is increasing then it is working.
When AT_client has reached its end, you can stop the Trace Collector and click "Show in folder".
1. Then attach the trace file here, so that I can forward to our internal team.

I will forward both trace file and log file to our internal team.

Thank you!

Best regards,
Øyvind

RE: nRF9160 NB-IoT signal strength polling

danielClark — Wed, 27 Mar 2019 13:43:32 GMT

Hi Øyvind,

I am running the standard AT_Client and can confirm(as KnutS says) that 1NCE is provided by Deutsche Telekom on Band 8 in Germany.

kind regards,

Dan

devzone.nordicsemi.com/.../2019_2D00_03_2D00_27T13_5F00_23_5F00_45.675Z_2D00_log.txt

RE: nRF9160 NB-IoT signal strength polling

KnutS — Wed, 27 Mar 2019 13:16:54 GMT

1NCE uses Deutsche Telekom Band 8

Regards

Knut

RE: nRF9160 NB-IoT signal strength polling

Øyvind — Wed, 27 Mar 2019 13:08:33 GMT

Hi Dan,

Are you running the standard AT_Client or a customized version? Please load the standard AT_Client and let it run for some minutes in LTE Link Monitor. Then, from the LTE Link Monitor, click Open Log File in the bottom part of the window (see image below):

Please provide a screenshot of the LTE Link Monitor as well. Can you please contact 1NCE and ask what band they support in NB-IoT? From the screenshot you have provided, the command %XCBAND shows the supported band for the modem.

Thank you!

Kind regards,
Øyvind

RE: nRF9160 NB-IoT signal strength polling

E3V3A — Wed, 27 Mar 2019 12:11:50 GMT

Could it be that a low-power mode is enabled, that is shutting down baseband if no outward connection are made or incoming?