NRF9160 not connecting ESM/EMM errors

RE: NRF9160 not connecting ESM/EMM errors

Achim Kraus — Wed, 11 Sep 2024 11:18:11 GMT

You're welcome.

RE: NRF9160 not connecting ESM/EMM errors

9160-DEV — Wed, 11 Sep 2024 07:53:04 GMT

I'm responding here in case anyone comes across this in the future. Unfortunately it was not solved & the SIM supplier was unable to find a fault either, so they have sent some new SIMs on a different network and the new ones worked instantly.

There's obviously an issue with the Vodafone SIMs I was supplied, and/or the Vodafone NB-IoT network in the south east of the UK.

Many thanks to Charlie and Achim Kraus for your help regardless.

RE: NRF9160 not connecting ESM/EMM errors

Achim Kraus — Fri, 16 Aug 2024 13:52:25 GMT

> Do all towers support NB-IoT for a given provider

I guess, this is more a question for your provider.

> +CEREG: 2,"2421","07D4E21F",9,0,19

the "9" indicates, that NB-IoT is used. The cell-id "07D4E21F" is split into tower and section (at least that works quite often like that). The tower part is "07D4E2" and the section "1F". cellmapper works with data feeded in by smart phones.So they usually don't list the NB-IoT section, but the towers.

You may also to a neighbor hood scan AT%NCELLMEAS to see, which cells are there. Unfortunately, cellmapper requires the PLMN and you need to check the candidates + tower id to see, if their tower is somehow near by.

Even if the SIMs has worked some months ago, I would check that with the SIM provider.

One pitfall maybe, that it used LTE (instead of LTE-M) and connects to "old towers". But once the towers are updated, then they detect it's LTE-M and reject the device, if it's SIm has only a LTE subscription. I would also not set the APN explicitly and relay in the first step on the one selected by the SIM.

Just in the case you want to try an other firmware, you may check with my demo zephyr-coaps-client using the prebuild nrf9160dk_nrf9160_ns_full.hex . Apply it with

nrfjprog --program nrf9160dk_nrf9160_ns_full.hex --chiperase --verify -r

and see, if that connects.

RE: NRF9160 not connecting ESM/EMM errors

9160-DEV — Fri, 16 Aug 2024 12:32:26 GMT

No change unfortunately, just better RSRP/RSRQ.

Do all towers support NB-IoT for a given provider, or is it the case that the NRF9160 polls each tower it finds until one appears that supports it? I've driven to four local 'big' towers and the same result at each.

RE: NRF9160 not connecting ESM/EMM errors

Achim Kraus — Thu, 15 Aug 2024 11:44:20 GMT

You're welcome.

"surprisingly far away (5-6 miles) minimum."

on the countryside that should still work. Otherwise you may try out testing closer to the towers ;-).

RE: NRF9160 not connecting ESM/EMM errors

9160-DEV — Thu, 15 Aug 2024 11:41:04 GMT

Thank you for this resource. The base stations it finds when I have run it again are all surprisingly far away (5-6 miles) minimum.

RE: NRF9160 not connecting ESM/EMM errors

9160-DEV — Thu, 15 Aug 2024 11:38:23 GMT

Thank you for looking at the trace.

I don't know if I'm reading it 100% correctly, but the EMM reject causes appear to change depending on the towers shown by +CEREG, eg EMM 15, 26, 29. See below.

+CEREG: 2,"2421","07C18A1F",9
+CNEC_ESM: 29,0
+CNEC_EMM: 19

+CEREG: 2,"2421","07C18A1F",9,0,19
+CNEC_EMM: 15

+CEREG: 2,"B951","00363015",9,0,15
+CNEC_EMM: 15

+CEREG: 2,"0390","07CA806E",7,0,15

+CEREG: 2,"241F","07B68F15",9
+CNEC_ESM: 26,0
+CNEC_EMM: 19

+CEREG: 2,"2421","07C18A1F",9
+CNEC_ESM: 29,0
+CNEC_EMM: 19

In the same trace I have "No Suitable Cells"(15) and "ESM Failure"(19), plus "User Authentication Failed"(29) and "Insufficient Resources" (26).

Is the user authentication error likely to be a low level SIM issue rather than AT+CGAUTH mistake?

Vodafone shows "Good" NB-IoT coverage using their coverage mapper tools online, and no tower issues in the area (even if there were, it seems to be changing between towers so would have thought that wouldn't be an issue?

The output of AT+COPS=? is

+COPS: (1,"","","23415",9),(1,"","","23430",9)

The first is Vodafone and the second one EE. When I ran it again I've also seen a third operator O2.

RE: NRF9160 not connecting ESM/EMM errors

Achim Kraus — Tue, 13 Aug 2024 14:52:53 GMT

According your trace

+CEREG: 2,"2421","07D4E21F",9,0,19

the modem connects to base station 513250 using NB-IoT and gets rejected.

Cellmapper.net shows that Vodafone (PLMN 23415) base station in Gillingham.

For the other +CEREG cellmapper doesn't know the base stations.

Maybe that helps.

RE: NRF9160 not connecting ESM/EMM errors

Charlie — Tue, 13 Aug 2024 13:16:45 GMT

Hi,

Checked your modem trace, it shows EMM reject cause is 15 (Cause #15 – No suitable cells in tracking area).

This EMM cause is sent to the UE if it requests service, or if the network initiates a detach request, in a tracking area where the UE, by subscription, is not allowed to operate, but when it should find another allowed tracking area or location area in the same PLMN or an equivalent PLMN.

NOTE 3: Cause #15 and cause #12 differ in the fact that cause #12 does not trigger the UE to search for another allowed tracking area on the same PLMN.

Not sure if your area is covered by NB-IoT network. You can further confirm with AT+COPS=?(manual PLMN search in that area to see what NB-IoT networks are available). Or double check with Vodafone about the coverage.

Best regards,

Charlie

RE: NRF9160 not connecting ESM/EMM errors

9160-DEV — Fri, 09 Aug 2024 19:17:19 GMT

Hello,

Thank you for your response. I struggled to get the PDN sample to do anything. Would the basic SLM application from the getting started setup work? I have successfully captured a trace file from that, using the Cellular Monitor app.

I tried the APN settings (AT+CGDCONT=0,"IP","mm.lpwan" and AT+CGAUTH=0,1,"vodafone","vodafone") however it did not help.

Please find the trace file attached. I would appreciate any insight you can offer.

Thank you

devzone.nordicsemi.com/.../NO_5F00_CON_5F00_2_5F00_OUTDOORS_5F00_trace_2D00_2024_2D00_08_2D00_09T18_2D00_56_2D00_01.937Z.mtrace

RE: NRF9160 not connecting ESM/EMM errors

Charlie — Mon, 29 Jul 2024 07:21:36 GMT

Ok, did you confirm your APN settings from Vodafone?

Can you try this official sample Cellular: PDN (nordicsemi.com)? If the problem still exists, you can record and share the modem trace of the test. I would be able to check what happens during the communication.

Best regards,

Charlie

RE: NRF9160 not connecting ESM/EMM errors

9160-DEV — Thu, 25 Jul 2024 14:14:52 GMT

Hello,

Unfortunately none of those fixed the issue.

RE: NRF9160 not connecting ESM/EMM errors

Charlie — Thu, 25 Jul 2024 13:44:56 GMT

Hi,

please see similar discussions on UK Vodafone NB-IoT network:

https://devzone.nordicsemi.com/support-private/support/281921#permalink=735252

https://devzone.nordicsemi.com/support-private/support/260734#permalink=619494

https://devzone.nordicsemi.com/support-private/support/246226#permalink=544395

Let me know which one or neither of them can solve your problem.

Best regards,

Charlie