Issues registering in network when changing from one operator to another

[Alejandro Vega]

Hello!

I am developing an application making use of libmm-glib high level API and
I am using a EM7455 Sierra Wireless modem. The modem is working under MBIM
mode (usb-composition).

I believe the issue I am experiencing is related to the *change of operator
/ SIM card*. The scenario is the following:

   1. The first SIM card I introduce is able to register in the network and
   connect using the APN I specify in order to establish a connection.
   2. I tell the modem to change the SIM card via internal AT command and I
   perform a system reboot (just to ensure everything starts fresh)
   3. After the reboot and after waiting some time (>5-10 minutes) the
   Modem is not able to register in any network and the signal quality is
   never updated. Modem remains as shown

*  --------------------------------*





*  Status   |                 lock: sim-pin2               |       unlock
retries: sim-pin (3), sim-pin2 (3), sim-puk (10), sim-puk2 (10)
   |                state: enabled               |          power state:
on               |       signal quality: 0% (cached)*
*-------------------------------------------*


and it never transitions to a "registered" state, which I understand should
be automatic.
I have tried the following commands in order to force the network
registration
mmcli -m 0 --3gpp-scan --> OK

mmcli -m 0 --3gpp-register-in-operator=xxxxx --> Returns: " error: couldn't
register the modem: 'Timeout was reached' "


My questions are:
-   Should signal quality be retrieved independent of the register state?
Does it depend on the modem registration status ?
-  Is there any *connection related configuration* that either the *modem
device or the ModemManager may be storing* ? If this would be the case, how
could this information be erased?
- Is there any way to ensure that the modem connection / register
parameters are reset to factory default ?


Thank you very much, any help will be appreciated.

-- 
Kind regards,

Alejandro Vega
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