AT command base script. Handles network disconnections if your service provider use NITZ. The FM350-GL modem has a limitied support for AT command and the only trigger for reconnection is the indication of received NITZ information, `+CTZV`.\
Support dual stack and received SMS will be stored in `/tmp/sms/rx` folder and the full path is sent to `/usr/bin/atc_rx_sms.sh <full path>`. `atc_rx_sms.sh` is not included in the package.