3G is closing its final curtain. This wireless network standard, which ushered in the age of the smartphone, will end in 2022 as carriers build more modern technology.

This means that devices that still rely on 3G, from smartphones to tablets to alarm systems, will no longer be able to connect once carriers pull the plug on 3G. The good news, however, is that this shutdown has been long overdue, giving carriers and device manufacturers ample time to ensure a smooth transition.

Here's what you need to know about the 3G shutdown and how it may affect you.

All major U.S. wireless carriers plan to shut down their 3G networks in 2022, though some are flipping the shutdown switch earlier than others.

AT&T will be the first to shut down 3G in February; T-Mobile will be the first to shut down Sprint's 3G network on March 31, remembering that the two carriers merged when T-Mobile absorbed Sprint's customers.

Verizon has previously postponed its 3G shutdown date, claiming that it will run out of 3G coverage on December 31, 2022.

Keep in mind that this does not only affect customers of a particular carrier. MVNOs that use a major carrier's network to provide wireless communications will lose access to 3G if the parent network shuts down 3G. In other words, if you are a Cricket Wireless customer, you will not have access to AT&T's 3G network after it shuts down in February.

There are several reasons why carriers are ready to pull the plug on 3G, the first being due to progress. The first commercial 4G network went live in 2009, followed by 5G a decade later; if 3G is included, many different networks will continue to operate.

"There are efficiencies to be gained by not operating three different networks," says Jason Lee, research manager for mobility at IDC. But at the end of the day, it comes down to frequency bands."

In other words, 3G connections use a portion of the radio spectrum. Once carriers no longer need to support aging 3G networks, they can allocate that spectrum to other forms of connectivity.

"Carriers need the frequency bands they use for 3G for more advanced services such as 4G and 5G," said Bill Menezes, director analyst at market research firm Gartner.

3G uses low-band and mid-band frequency bands to keep devices connected. These frequency bands are particularly valuable real estate because they can travel longer distances and penetrate buildings more easily than high-band frequency bands. Therefore, carriers are likely to use their freed-up 3G frequency bands to improve the reach of their expanding 5G networks.

Most cell phones launched in the past few years will work just fine even if 3G networks are no longer available. The important thing is to have a phone that supports voice over LTE, which is a very good idea.

As an example, Leigh points out that Verizon stopped certifying 3G handsets in 2018. This is three years ago, plenty of time to upgrade to more modern devices that can connect to the LTE network.

Still, while the number of handsets affected is not large, it is not an insignificant number; Menezes cited figures released by AT&T in September, stating that 2.7% of customers would be affected by the 3G shutdown. 195 million customers at the end of September or more, which equates to about 5 million customers.

Carriers have known about the transition for some time and are likely to be in contact with customers whose phones will lose 3G connectivity at some point in 2022. Customers of each carrier can find information pages for AT&T, Verizon, and T-Mobile. (The latter carrier also has information for former Sprint customers. )

The greatest impact would be on low-income households that do not have the means to immediately upgrade to a new phone. However, the Federal Communications Commission does offer Lifeline Service, which provides discounts on phone service for some low-income consumers. More information about this program can be found on the FCC's web page describing the 3G network shutdown.

Other phones affected are not necessarily those used for everyday connectivity; Leigh notes that his father keeps his old flip phone in the glove box of his car to stay connected.

The 3G shutdown affects more than just phones. Other devices also use 3G connections and are not upgraded as frequently as phones, making the impact of a 3G network shutdown more severe.

"My guess is that cell phones are in the minority [of affected 3G devices]. The vast majority are Internet-of-things devices."

Specifically, all connected devices, from in-car navigation systems to home security systems to medical devices, rely on 3G. The same is true for older tablets and e-readers that offer cellular connectivity, which, again, are not devices that are updated as frequently as smartphones.

There are good news and bad news aspects to connected devices that rely on 3G. The bad news is that you will likely be burdened with contacting your service provider to see if the affected device is upgradeable. However, there is a good side. Service providers and device manufacturers knew well in advance that this shutdown was coming.

"They've known this for years and have been working on it," Menezes said.

A possible exception might be alarm system manufacturers, who have sounded the alarm themselves this year that the COVID-19 pandemic has reduced their ability to go into homes and make sure their systems are updated. Again, you would need to check with your home security service before 3G shutdown.

The U.S. is years ahead of the rest of the world in 3G network outages, says IDC's Lee. This could create a tricky situation for international travelers who expect to bring a 3G phone and insert a local SIM card for their trip to the US. Once the 3G network is turned off, those phones will not work in this country.

As for the rest of the world, in the UK, wireless carriers EE and BT both aim to turn off their 3G networks in 2023. The UK government aims to off both 2G and 3G by 2033 at the latest.