Sprint and Verizon iPhone 5s have 4G LTE limitations

Want to use your smart phone to chat with a friend as you both search the Web for a suitable restaurant, or to get live help to supplement turn-by-turn driving directions from a navigation app? Then an iPhone 5 from Verizon and Sprint is not the phone for you.

With their testing of the iPhone 5 almost complete, Consumer Reports engineers have confirmed that the Verizon and Sprint versions of the phone can't simultaneously support a phone call and an Internet-based connection over the cellular network.

The restriction is nothing new to 3G CDMA phones, including all past versions of the iPhones that run on CDMA-based networks. But the iPhone 5 appears to be the only Verizon or Sprint phone running on newer 4G LTE networks that retains this limitation. All other 4G LTE phones we've tested from these carriers allow you to surf and talk. So does the AT&T version of the iPhone 5, which a carrier spokesperson says automatically switches to the carrier's 4G HSPA+ or 3G GSM networks to allow simultaneous voice and data activity. Indeed, all GSM-based 3G and 4G smart phones, including the AT&T iPhone 4S and phones running on T-Mobile, have the same capability.

The only way Verizon and Sprint iPhone 5s can offer simultaneous voice/data capability is via Wi-Fi—a connection that's hardly easy to obtain or maintain when you're on the move. Absent of having a Wi-Fi connection, Verizon and Sprint iPhone 5 users will receive a message that reads "Cellular data connections are not available during this call" when they try to launch the Web browser—or any Internet-based app like Facebook or Twitter during a call.

Likewise, any incoming call will temporarily suspend data functions, including the Apple Maps new navigation app—a situation confirmed by Consumer Reports auto testers. This means a lengthy phone conversation could cause you to miss a turn, for example. What's more, according to our auto testers, if a user deviates from the route while on a call, the navigation app gets stuck trying to recalculate, and even gets hung up. Even when the call is ended, our colleagues found, it can remain stuck "recalculating" the route.

You can still call and text from the Verizon and Sprint iPhone 5s. But since you won't be able to talk and use data-dependent features simultaneously, phone multi-taskers may want to think twice about getting one of these phones.

Related:
The iPhone 5 is another winner, despite that Maps app
New Apple Maps navigation app for iPhone disappoints

—Mike Gikas