Network selection
Here we will discuss how to perform:
Operator selection
Check current network
Check available networks
Operator selection
To force a SIM to a network, we can use the following AT command:
AT+COPS=<mode>,<format>,<operator>
Here <mode> determines if the network selection is done automatically or forced to a network specified in <operator> using the format specified in <format>.
Possible values for <mode> are as follows:
<mode>
Meaning
Actions
0
Automatic selection (<operator> field is ignored)
SIM will connect to any operator
1
Manual selection (<operator> field is mandatory)
SIM will only connect to the operator specified
2
Deregister from network
SIM will not connect to any operator
3
Sets the <format> for the read command +COPS? (<operator> field is ignored)
No attempt to connect/ disconnect
4
Manual selection, if possible (<operator> field is required). Switches to automatic (<mode>=0) if manual selection fails
SIM will attempt to connect to the operator specified and switch to any operator if that fails.
Possible values for <format> are as follows:
<format>
Meaning
0
<loperator> Long format alphanumeric (E.g. T-Mobile USA)
1
<soperator> Short format alphanumeric (E.g. TMO)
2
<noperator> Numeric (E.g. 310260) which is the Country and Network code (MCC, MNC)
The <operator> can be retrieved from the result of a AT+COPS=? to check available networks.
Some examples below of how to perform operator selection in various modes/ formats.
Check current network
To check the network registration status of the SIM, we can use the following AT command:
AT+COPS?
This command returns the current <mode> and currently selected operator. If operator is not selected the <operator> and <format> are omitted. The results of the command could be as follows:
<mode>
Meaning
0
Automatic selection, registered to network if <operator> and <format> are present
1
Manual selection, registered to network if <operator> and <format> are present
2
Deregistered from network
4
Manual selection, if possible, registered to network if <operator> and <format> are present
Examples below:
Check available networks
To scan and report visible networks the network registration status of the SIM, we can use the following AT command:
AT+COPS=?
This command returns a list of quadruplets, each representing an operator present on GSM network followed by a list of supported modes and formats.
The quadruplet consists of:
+COPS: <status>,<loperator>,<soperator>,<noperator>
where the status carries the following meaning:
Status
Meaning
0
Unknown
1
Available
2
Current
3
Forbidden
Examples below:
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