Existing Sprint or Verizon Wireless customers won't be surprised by what I'm about to say, but it's worth saying anyway: The iPhone 5 won't allow for calls and data at the same time if you're using one of those two carriers.
If you're using AT&T, it will.
As the New York Times' Brian Chen points out, this odd issue has to do with the way 4G LTE works.
"The technology in 4G LTE networks does not currently handle voice transmissions; it only does data. So when you place a phone call on a 4G LTE smartphone, it’s actually rolling back to the carrier’s older second- or third-generation network, according to AnandTech, a Web publication that does deep analysis on hardware," Chen explains.
This means that when someone using an AT&T-based device makes a phone call using an iPhone 5, everything rolls back to the carrier's older network … which can handle both calls and data at the same time. This is not the case for the older CDMA networks to which Verizon- and Sprint-based devices roll back.
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