I have EM7565 cellmodems and by default I have enabled AUTO-SIM (SIM based automatic Image switching) feature for them so that the carrier PRIs and associated fw images are automatically selected by the SIM that is activated.
I know SIM cards will specify MNC / MCC codes and if the preferred PRI differs from the active one, the EM7565 will change carrier PRI (and FW if needed) and reboot when switching SIMs.
This works well for ATT and Verizon SIMs, but not for T-mobile SIMs.
On one of EM7565 modules I have, its FW/PRIs are as following:
# /etc/scripts/modem-cmd 'AT!IMAGE?' response: 'TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID FW 1 GOOD 18 0 0 ?_? 01.08.04.00_? FW 2 GOOD 3 0 0 ?_? 01.07.02.00_? FW 3 GOOD 19 0 0 ?_? 01.14.02.00_? FW 4 EMPTY 0 0 0 Max FW images: 4 Active FW image is at slot 3 TYPE SLOT STATUS LRU FAILURES UNIQUE_ID BUILD_ID PRI FF GOOD 0 0 0 002.008_005 01.07.02.00_ATT PRI FF GOOD 0 0 0 002.012_001 01.08.04.00_GENERIC PRI FF GOOD 0 0 0 002.001_000 01.08.04.00_SIERRA PRI FF GOOD 0 0 0 002.003_000 01.14.02.00_TMO PRI FF GOOD 0 0 0 002.015_002 01.08.04.00_VERIZON Max PRI images: 50' #
Specifically, the T-mobile specific FW/PRI are from the Release 15, whereas other FW/PRIs are from older releases.
Anyway, with AUTO-SIM enabled with T-mobile SIM card, data connection can be established and work well, however, from AT!IMPREF? command I can see that it is the GENERIC FW/PRI that has been activated, instead of the TMO ones:
# /etc/scripts/modem-cmd 'AT!IMPREF?' response: '!IMPREF: preferred fw version: 00.00.00.00 preferred carrier name: AUTO-SIM preferred config name: AUTO-SIM_000.000_000 current fw version: 01.08.04.00 current carrier name: GENERIC current config name: GENERIC_002.012_001' #
Only if I explicitly specify AT!IMPREF=“TMO” command, could it swith over to the T-mobile FW/PRI:
# etc/scripts/modem-cmd 'AT!IMPREF?' response: '!IMPREF: preferred fw version: 01.14.02.00 preferred carrier name: TMO preferred config name: TMO_002.003_000 preferred subpri index: 000 current fw version: 01.14.02.00 current carrier name: TMO current config name: TMO_002.003_000 current subpri index: 000' #
Lastly, the MNC / MCC codes read from T-mobile SIM are for T-mobile (310 260):
# mmcli -i 2 SIM '/org/freedesktop/ModemManager1/SIM/2' ------------------------- Properties | imsi : 'xxxxxxxxxxxxxxxxx' | id : 'yyyyyyyyyyyyyyyyyyyyyyy' | operator id : '310260' | operator name : 'T-Mobile' #
So, why didn’t AUTO-SIM switch over to T-mobile FW/PRI with T-mobile SIM card by default? how to further diagnose?
Many thanks in advance!