How to change G2 or G-F4 Carrier Frequency using AT commands for different regions around the globe.

Some regions around the globe require a 'G2' or 'G-F4' cellular device to have the default frequency of operation changed.

The command AT+WMBS=x,x is used to set the Carrier frequency.

See the following document for a full list of regions and known frequencies and settings used:

Command Summary:

Band selection is set using the +WMBS command. The +WMBS setting is stored to non-volatile memory on execution.

write syntax: AT+WMBS=<band>,<param>

<Band> Frequency Band Configuration
0 mono-band mode 850 MHz
1 mono-band mode 900 extended MHz (900E)
2 mono-band mode 1800 MHz
3 mono-band mode 1900 MHz
4 dual-band mode 850/1900 MHz
5 dual-band mode 900E (extended) /1800 MHz
6 dual-band mode 900E (extended) /1900 MHz
7 quad-band mode 850/900E (extended)/1800/1900 MHz

Note: Band option 7 (quad band mode) is not available on -F4 models and is only supported on firmware versions R7.45.1 and newer for -G2 models.

<Param> Type of Change
0 The wireless modem must be reset to start on the specified bands.
Default value is 0 if a value is omitted.

1 The change is effective immediately. The GSM stack is restarted with the specified