The retirement of the 3G network is to make room for more advanced networks, like 5G, which is much faster. Once the 3G network is shut down, 3G cell phones won’t work—no phone calls, including dialing 9-1-1, and no online access.

AT&T plans to finish terminating its 3G network by February 2022. T-Mobile announced that it will complete shutdowns of its 3G network by July 1 and Sprint’s 3G network by March 31. And Verizon put its 3G network to rest at the end of 2022.

A new generation of cellular standards has appeared occurred every 10 years since 1G systems were introduced between 1979 and the mid-1980s. Each generation is characterized by new frequency bands, higher data rates, and non–backward-compatible technology.

The first commercial 3G networks were introduced in mid-2001.

The end of 3G will affect access to emergency medical care for seniors nationwide, according to Chris Holbert, the chief executive officer of SecuraTrac, a company that makes emergency medical response systems for consumers.

While leaving 3G behind “may seem like a great push toward technological advancement, millions of 65-plus Americans rely on these networks to power and connect their medical devices for help in case of an emergency or accident. For some, an upgrade or replacement may not be possible, leaving them disconnected for emergency services,” Holbert said.

The switch affects 3G cell phones and other other devices that also rely on 3G networks, such as medical devices, tablets, smart watches and home security systems. If you do not replace or upgrade your device, your device will not function.

To replace 3G devices, most carriers are offering free and low-cost replacement phones. A 3G phone user who wants to make a major upgrade in phones can ask carriers for special offers on smartphones.

3G telecommunication networks support services that provide an information transfer rate of at least 144 kilobits. Later 3G releases, often denoted 3.5G and 3.75G, also provide mobile broadband access of several megabits to smartphones and mobile modems in laptop computers. This ensures it can be applied to wireless voice telephony, mobile Internet access, fixed wireless Internet access, video calls and mobile TV technologies.

The Federal Communications Commission governs the cell phone industry nationally. At the state level, the rates and services of phone carriers operating in Washington are regulated by the Utilities and Transportation Commission.