AT^SYSCFG AT command is used to set the system mode, GW access order, frequency band, roaming support, domain, and other features.
//System configuration command support
^SYSCFG: (2,13,14,16),(0-3),((2000000400380,"GSM900/GSM1800/WCDMA900/WCDMA2100"),(4a80000,"GSM850/GSM1900/WCDMA850/WCDMA1900"),(3fffffff,"All Bands")),(0-2),(0-4)
//Read the ccurrent setting
//Mode is automatic, Acquisition order is WCDMA>GSM, band is any band, roaming is supported, Circuit switch and packet switch domains are supported
//Configure the mode for WCDMA only