Is it AT&T, Verizon, or T-Mobile 3G network that is shutting down this year? Or not?
FCC Guidance " Plan Ahead for Phase Out of 3G Cellular Networks and Service"
“home security systems, and other connected products may be using 3G network services. And don’t forget about devices that use cellular connectivity as a back-up when a wired internet connection goes down. If the device is not labeled, contact the monitoring company or other service provider to confirm how the device connects and whether your device may be impacted.”