BATON ROUGE - Last week, AT&T began its 3G network sunset. It didn't just affect phones, but everyday appliances.

Some of that technology may be in your house, and you might not know it.

Acadian On Call has been supplying medical alert systems for the last 25 years. The system is an electronic device that sends a signal anytime a person is in a state of emergency. It connects that person to someone who can help.

Two years ago, Acadian On Call says it had about 4,000 customers that had been utilizing 3G technology. A year ago, and as recently as a month ago, Acadian On Call says it started mailing letters letting customers know what is happening regarding 3G technology.

Those letters encouraged customers to call Acadian so that a new unit can be delivered, free of charge. Brandon Niles is the Senior Director of Acadian On Call, and he says there are still customers who have not responded.

"About 400 of them we're trying to get in touch with," Niles said. "We're still sending letters, still calling each and every day."

Acadian is asking customers to reach out to them so that the new units can be delivered. That goes for other devices, too.

"If you have a security system or a medical alert device, and you're not sure if it's 3G, you need to call your local alarm company right away," Niles said.

At the end of 2020, the Alarm Industry Communications Committee estimated there were six million alarm systems with 3G technology that needed to be replaced.

Four million have been swapped out with the new technology, but that means there are still two million out there.

"This might be impacting them, and they just might not know it," Niles said.

Which is why Acadian is trying to get the word out to check your system.

The 3G networks for T-Mobile and Verizon are still up and working, but those are scheduled to shut down later in 2022.

Sunsetting older infrastructure makes room for the new and frees up bandwidth for faster signals.