Sounds like an HTC thingy. Unless of course he's testing it connected to WiFi, cuz it will definitely support voice and data on 3g while connected to WiFi. But 3g itself doesn't support simultaneous voice and data - thus all of the old AT&T commercials touting their ability to do both, which (thank goodness) we don't have to put up with any more.
I don't know about the rezound, but the tbolt supports it because it uses a variation of cdma called eHRPD or something like that, which was put on there because of pressure from the iPhone. Idk why the rezound would have it
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