EM9191 and sysmoisim, IMSI changes after a few seconds

IoT Modules MC/EM Series
1

Hi,
I can successfully provision a sysmocom Isim with a valid thirdparty eSim profile on an em9191. After enabling the the profile I can see in the radio trace the real IMSI of the sysmocom card. Even a network connection can be established. at+cimi reports the expected IMSI of the sim card. But after a few seconds, the IMSI changes to 15 times 9, the network connection breaks and every reattach is rejected. at+cimi reports this 15 times 9 too. Now I’m stuck, I have no idea what is happening or what I am missing. Anyone an idea or a hint?
TIA
andreas

The fw is the latest generic available:

Manufacturer: Sierra Wireless, Incorporated
Model: EM9191
Revision: SWIX55C_03.14.10.04 25b6d9 jenkins 2024/02/29 17:20:23
IMEI: 355890347224383
IMEI SV: 27
FSN: 783067204002B1
+GCAP: +CGSM,+DS,+ES
2

what is the return of the following?


ATi3
AT!impref?
at!uims?
AT+ccid
AT+CIMI
AT+CGDCONT?
AT!SELRAT?
AT!BAND?
AT!GSTATUS?
3

Hi,
below the values you requested. I hope these give some insights. They are taken after the modem has switched the imsi (before it was 23210…)
Thanks,
andreas

ati3
Manufacturer: Sierra Wireless, Incorporated
Model: EM9191
Revision: SWIX55C_03.14.10.04 25b6d9 jenkins 2024/02/29 17:20:23
IMEI: 355890347224383
IMEI SV: 27
FSN: 783067204002B1
+GCAP: +CGSM

at!impref?
!IMPREF: 
 preferred fw version:    03.14.10.04
 preferred carrier name:  GENERIC
 preferred config name:   GENERIC_030.094_000
 preferred subpri index:  000
 current fw version:      03.14.10.04
 current carrier name:    GENERIC
 current config name:     GENERIC_030.094_000
 current subpri index:    000

at!uims?
!UIMS: 0

at+ccid
+CCID: 89852245280007924955,89044045116727494800000004481694

at+cimi
999999999999999

at+cgdcont?
+CGDCONT: 1,"IPV4V6","","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 2,"IPV4V6","ims","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0

at!selrat?
!SELRAT: Unknown RAT mode. Use AT!SELRAT to set band. 
00001228
00000000

at!band?
Index, Name
00, All bands

at!gstatus?
!GSTATUS: 
Current Time:  283		Temperature: 26
Thermal Mitigation Level: 0
Reset Counter: 1		Mode:        ONLINE         
System mode:   WCDMA      	PS state:    Not attached 
WCDMA band:    WCDMA 900  
WCDMA channel: 2938
GMM (PS) state:DEREGISTERED   	LIMITED SERVICE
MM (CS) state: IDLE           	LIMITED SERVICE

WCDMA L1 state:L1M_PCH        	LAC:         1B68 (7016)
RRC state:   DISCONNECTED   	UTRAN Cell ID: C3FE2760 (10518885)
Rx0 RSSI C0:   -52		Rx1 RSSI C0:  --- 
Rx0 RSSI C1:    --- 		Rx1 RSSI C1:  ---
4

AT!UIMS has been set to 0 which means physical sim slot, but not eSIM
Do you have an eSIM component connected to the physical SIM slot?

5

Yes, this sysmoisim is inserted in slot one.

6

then is that the physical sim card has problem?

how about setting AT!SELRAT=0?

What is the correct APN for this SIM?

7

Well, when I delete and re-provision the profile and insert the SIM into a Telit FN990 then I can establish a net connection. The IMSI stays as it should.
Regarding at!selrat=0, no change. And regarding the APN, I have to figure out.
For me it seems the modem ‘re-writes’ the IMSI and makes the SIM unusable.

8

then if you now put the workable SIM from FN990 to EM9191, can it establish data connection?

9

Yes, for a very short time it seems to work. Below a trace from our application to show the short time frame:

10.12.24 09:21:54 mbm3-2: Sierra Wireless EM9191@usb:3-2 appeared
10.12.24 09:22:00 mbm3-2: ICCID: 89852245280007924955
10.12.24 09:22:00 mbm3-2: IMSI: 232104070214249
10.12.24 09:22:00 mbm3-2: PIN ok
10.12.24 09:22:01 mbm3-2: Revision: SWIX55C_03.14.10.04 25b6d9 jenkins 2024/02/29 17:20:23
10.12.24 09:22:01 mbm3-2: IMEI: 355890347224383
10.12.24 09:22:01 mbm3-2: network connection on 22802 (RedteaGO) ready
10.12.24 09:22:01 mbm3-2: roaming from home 23210 to net 22802
10.12.24 09:22:01 mbm3-2: 60, 0f@LTE, RSSI:  -65dBm, RSRP:  -93dBm, RSRQ:  -11dB, SINR:    0dB
10.12.24 09:22:01 mbm3-2: Network time: 10.12.24 09:22:00
10.12.24 09:22:01 mbm3-2: PDP connection ready
10.12.24 09:22:01 mbm3-2: IP connection ready
10.12.24 09:22:02 mbm3-2: IP connection lost
10.12.24 09:22:02 mbm3-2: PDP connection lost

I even have a radio trace (QXDM enabled) where I see the the RRCConnectionSetupComplete (Attach Request) with the 23210 IMSI. 5 seconds later I see again an RRCConnectionSetupComplete with the magic 999 IMSI.

10

can you do a simple test by using manual registration (AT+COPS=1,2,xxx) to see whether it can register to network?

11

Unfortunately no success. At the time I type at+cops=1,2,“22802”, the IMSI has already changed.
Here a short correction, the sysmocom Product is here: sysmocom-euicc

12

If you type the command after imsi changed, can it register network?

13 
at+cimi
999999999999999

OK
at+cops?
+COPS: 1
OK
at+cops=1,2,"22802",13
+CME ERROR: no network service
14

Is this sim card for multiple imsi configration?

Did you check if same apn is used in telit module?

15

I’m not aware of. I can not say yes or no.

Yes I did. The same apn is used in the telit module.

16

Maybe the network operator knows

Actually you need to contact distributor for qxdm log analysis

17

So, I verified the content of the primary eSIM profile before and after inserting it into the em9191.
The IMSI of the profile is 232104070214249 before inserting. After inserting and powering up the modem, the SIM changes to 999999999999999. So, the modem re-writes the IMSI on the profile. Due to whatever reasons.
I checked another eSIM profile regarding IMSI and here the IMSI stays the same. Seems that this is profile dependent. But I didn’t expect the modem to re-write the IMSI anyway.