AT&T's 3g network allows simultaneous voice and data. Verizons 3g does not. But with 4G, you can.
Thats not quite right, my Thunderbolt does it just fine. To answer the question, when I make a call, all my data service goes out. This is the first "smart phone" that has ever done this. I was just wondering if there is something wrong with the phone or setting wrong. It comes on fine when the call ends.
It is a CDMA vs GSM thing. GSM carriers like AT&T and most all around the world have a system that permits calls and data to work at the same time as these are independent services.
CDMA is older and only supports calls or data. Another system added into CDMA with a separate functioning antenna such as 4g could in theory work. But for now its a no go. Welcome to Verizon...Sprint is the same also.