Hello,
I have an EM12-G module and I was trying to test the roaming function, but failed. The home network operator of the SIM has 22210 LAI.
I’ve sent COPS=? and got the list of forbidden and allowed network operators.
Then, I’ve used:
AT+QCFG=“nwscanmode”,0
AT+QCFG=“roamservice”,2
AT+COPS=1,2,22201
where the last parameter of COPS is the LAI of the network operator I wanted.
The response of the COPS command was CME ERROR: 30, which seems to be corresponding to a No Network Service error.
The location of the test was covered by the 22201 operator. Also, it is an allowed operator.
Can someone please tell me why the roaming is not working?
The display of 1 (available) vs 3 (forbidden) in the +COPS: result is controlled by the user-editable EF_FPLMN SIM file at SIM address 0x6F7B (Forbidden PLMNs).
That file can be read using: AT+CRSM=176,28539,0,0,0
Shows that I have 50502 and 50503 forbidden, with everything else available.
But just because a network isn’t listed in the EF_FPLMN file doesn’t mean there is a roaming agreement in place, and that network’s cells can be used for roaming. It just means it’s not being blocked by being included in that SIM file.
As I said, you can overwrite that file in any case.
This is not the correct syntax. The Operator field is defined in 3GPP 27.007 as “string type”.
That means the correct syntax is: AT+COPS=1,2,"22201"