Modem upgrade failed

[Carter]

hi,

  When verifying the modem upgrade, if the network type is set to support both Cat-M and NB (AT%XSYSTEMMODE=1,1,0,0), the actual network that connects is NB, and the modem upgrade will fail. However, when the network type is set to only support NB (AT%XSYSTEMMODE=0,1,0,0), the modem upgrade is successful.

The same result occurs when using the v2.6.1\nrf\samples\cellular\http_update\modem_delta_update example for verification on the nRF9160-DK.NCS version: V2.6.1

• Example and logs that support only NB

         modem_delta_update_nb.zip

         

• Example and logs that support both NB and Cat-M

       modem_delta_update_nb_cat-m.zip

      

What is the reason for this? Can you give me some ideas to solve it? thank you

[Charlie]

Hi,

Thank you for reporting this issue. However, I don’t believe it is specifically related to the AT%XSYSTEMMODE command.

From the logs, I noticed the devices are connected to two different cells, and neither cell appears to handle DNS reliably.

To further investigate, could you try the following?

1. Test with NCS 2.9.0 using the Cellular: HTTP modem delta update sample along with the latest MFW 1.3.7. There are several improvements and bug fixes since MFW 1.3.5 according to release notes. 
2. Perform tests in a different location to ensure both device connect to the same cell station for a proper comparison.

Let me know the results or if you have additional observations.

Best regards,

Charlie

[Carter]

Hi,

 The same issue still occurs when using NCS 2.9.0.

[Charlie]

It looks you are still testing with MFW 1.3.6. Could you please try using MFW 1.3.7 instead?

If the issue persists, could you share both the modem trace and log files for the following two settings when running test? Unfortunately, I am unable to replicate the test on my side since both LTE-M and NB-IoT are available in my area.

1. AT%XSYSTEMMODE=1,1,0,0
2. AT%XSYSTEMMODE=0,1,0,0

Looking forward to your update.

Best regards,

Charlie