This transition is different from earlier cellular generation shifts, which means 4G could be useful a lot longer.
5G buzz is everywhere. Billboards display the latest, fastest gadgets like Samsung's Galaxy S10 5G, TV ads tout the benefits of the fast speeds and carriers are jockeying for title of best 5G network. But with 5G networks in the US only a few months old, your 4G phone isn't destined for the junk heap yet. In fact, the ramp up to 5G means your 4G phone may actually get better.
5G is touted as a game-changing technology, with the ability to dramatically boost the speed and coverage of wireless networks. It can run between 10 and 100 times faster than your typical 4G cellular connection today. It's quicker than anything you can get from a physical fiber-optic cable in your house. And latency, the amount of time between when your phone pings the network and when it responds, is faster than what Wi-Fi provides.
But 5G also has limitations. The higher-frequency bands rolled out first by Verizon and AT&T, called millimeter wave, provide super-high speeds, but the signals travel only short distances. Things like trees and double-pane glass block millimeter wave signals. T-Mobile, Sprint and most carriers in Europe and Asia have opted to build their broader 5G networks using sub-6GHz or mid-band spectrum, the lower-frequency airwaves that are more stable but slower than millimeter wave. They travel longer distances, but speeds can be similar to what you find with some LTE connections, not the dramatic leap you get with millimeter wave.
"Right now there are huge compromises with 5G in terms of design, coverage and cost," IHS Markit analyst Wayne Lam said. "4G LTE and 5G will coexist for a very, very long time."
There are some unique features of the shift to 5G that can help the operators move quicker than before -- without forcing everyone onto the faster network at once. Here's how 4G and 5G will coexist for years to come:
4G and 5G coexistence
The move from 4G to 5G is different from past network upgrades. 5G isn't replacing 4G, like how 4G overtook 3G. Instead, 5G is building on 4G LTE, using updated radios and software. Right now, if you have an early 5G phone phone and upload videos to Google Photos, you're actually using a 4G LTE connection for that uplink.
"This is the first time so many aspects of [the old and new network] are shared," said Gordon Mansfield, AT&T vice president for converged access and device technology. "Some things we'll do for 5G are inherently backward compatible and will lift the capabilities of 4G."