"Is your mobile phone more than a few years old? You may need to upgrade—fast. The shutdown of 3G cellular service by all of the major cell-phone carriers—AT&T, T-Mobile (which owns Sprint) and Verizon—is under way and will be completed next year. The long-planned sunset of 3G will free up airwaves for 5G and other advanced services. That’s the good news. The bad news is that if you have a device that relies on the old wireless standard, you will no longer be able to use some data services, send texts or make phone calls, including dialing 911."