GENERIC (preferred/current both 03.17.09.00_GENERIC)
Host
OpenWrt router, MHI/PCIe
AT access
/dev/ttyUSB0 via option/qcserial kernel drivers
SIM & Network
Operator: China Mobile (MCC-MNC 460-00)
SIM type: Standard consumer SIM (personally registered, non-IoT)
5G SA: n41, 100 MHz BW, RRC Connected, MM5G Registered Normal Service
LTE: B3/B34/B39/B40/B41 — all attach normally
Problem Description
SMS (both send and receive) works flawlessly on LTE (SELRAT=01), but completely fails on 5G SA.
Whether the RAT is set to Automatic (AT!SELRAT=00) or NR5G Only (AT!SELRAT=06), AT!GSTATUS? consistently shows:
IMS reg state: NOT REGISTERED
IMS mode: Normal
IMS Srv State: UNKNOWN SMS, UNKNOWN VoIP
NSA/ENDC mode (AT!SELRAT=02) is not available on this firmware/PRI combination. The only available RAT options are:
00 = Automatic
01 = LTE Only
06 = NR5G Only
Troubleshooting Performed
All of the following were attempted — none resolved the issue:
#
Approach
Command(s)
Result
1
SMS over NAS (SMSoNAS, 3GPP 24.501)
AT+CGSMS=3
Acknowledged (OK), SMS still not received
2
SMS over PS / IMS
AT+CGSMS=1
IMS never registers on SA
3
Phase 2+ SMS enablement
AT+CSMS=1
Returns 1,1,1, no effect
4
Protocol stack full reset
AT+CFUN=1
Module re-registers; IMS remains NOT REGISTERED
5
SMSoNAS shortcut toggle
AT!CELLSMS=1
No effect
6
SMSC verification
AT+CSCA?
+8613800851500,145 — correct
7
SMS storage check
AT+CPMS?
Normal ("ME",0,255...)
8
SMS notification check
AT+CNMI?
Normal (2,1,0,0,0)
9
RAT switching
SELRAT=00/01/06
01 (LTE) SMS works; 00/06 (SA) IMS NOT REGISTERED
10
CUSTOM option audit
AT!CUSTOM=?
No SMSoNAS/IMS/MMWave-related entries available
Questions
Does SMSoNAS require any additional NV item or CUSTOM flag to be enabled on EM9190 with GENERIC PRI 030.115_000? If so, what are the specific parameters?
Is there a way to force IMS registration on the 5G SA connection, or to re-enable NSA/ENDC mode so SMS can ride on the LTE anchor?
Is simultaneous SA data + LTE IMS registration possible on the EM9190 (dual-registration or equivalent)? If not, what is the recommended configuration for a setup that needs both 5G data and reliable SMS delivery?
Any guidance would be greatly appreciated. Happy to provide additional AT!GSTATUS? / AT!IMAGE? / AT!BAND? output or QMI logs if needed.
I tried your band config on my EM9190 with China Mobile (MCC 460-00, n41). SMS over LTE now works, but the module only camps on LTE B41 (20 MHz, ~30 Mbps), never triggers ENDC to n41. It seems B41 is not configured for n41 EN-DC on China Mobile’s network here — they typically use B3 (1800 FDD) or B39 (1900 TDD) as the NR anchor for n41.