Registration rejected after SDK update

[Bernhard]

Hello,

I am trying to update a project from SDK v2.6.1 to v3.1.0, but with the updated SDK my device is not able to connect to the network anymore:

<wrn> lte_lc: Registration rejected, EMM cause: 15, Cell ID: 1395462, Tracking area: 49, LTE mode: 7

I also made a temporary version with SDK v2.7.0 (to test only required changes for sysbuild and HWMv2), which was also working fine.

Flashing back the original merged.hex is working fine, so I guess it has nothing to do with the network itself.

In was not able to find anything related in the changelogs, migration guides or the samples.

I am using modem firmware v1.3.7

Any hints would be helpful
Thank you.

Best regards,
Bernhard

[Benjamin]

Hi Bernhard,

Do you experience the same issue if you build and flash a sample from v3.1.0?
What SIM are you using?

Best regards,
Benjamin

[Bernhard]

Hello Benjamin,

I have build the GNSS sample for my custom board with basically the same output Registration rejected

I am searching for the differences in the files but its hard to find anything, I have played a lot with the
CONFIG_MODEM_ANTENNA ...
settings, especially as they are also partly auto-configured for the boards, but always with the same output.

Any other ideas?
Thank you

Best regards,
Bernhard

[Bernhard]

I just noticed that I did not answer the second part of your question.

I am using a Magenta SIM, did not pay too much attention to it as it is working with older SDKs.
Any special parameters I should check here?

[Benjamin]

Thanks. Some more questions:

• Do you see the same issue on a DK?

• Are you using the same MFW with both the working and non-working NCS versions?

• Have you tried any other NCS versions between 2.7.0 and 3.1.0?

It’s unusual if no other samples work either. Could you take a modem trace and upload it here? I’ll share it with the modem team for review.

Best regards,
Benjamin

[Bernhard]

Hello Benjamin,

I tested with multiple SDK versions now and actually the problem is more connected to the update to HW model v2 than to the SDK update itself. All versions from (including) v2.70 are affected.

I made a modem-trace based on gnss sample (with my application I got memory overflows when trying to build with modem-trace):

    modemtraces.zip

I will try to test it also on a DK in the next few days.

Thank you!

Best regards,
Bernhard

[Benjamin]

Thanks,

Just to confirm, the GNSS sample works on your board in pre v2.7.0 versions?

[Bernhard]

Hello Benjamin,

I have to apologize, I think it's actually kind of working.

It seem's like I just had bad reception which did not print error messages in older SDK versions, but the lte modules were changed a lot so the behaviour is now different, I think also the retry timeout is shorter now.

Under better conditions / on a different location it's actually working.

Thank you anyhow!

Best regards,
Bernhard