WHY WE CAN'T USE VOICE AND DATA ON THE IPHONE AT THE SAME TIME?
Apple didn't put another antenna for it to work. It's been explained quite a few times.
Tidbits, but I'm use the same phone with other carrier and it works perfectly fine. why not with verizon?
It's doesn't have additional antenna. There are already 4 in there. Apple chose not to put another one.