You can do voice and data at the same time on Verizon if you have the advanced calling features enabled on both the phone and your Verizon account. You'll be using the VoLTE feature so the voice call will be using the LTE bands along with data. The simplified story is that when in an LTE coverage area but without VoLTE turned on, the voice calls go over the CDMA network and data goes over the LTE network. Phones only have one radio antenna now so you can't do both CDMA and LTE at the same time. There were some older Verizon phones that could do simultaneous voice and data back when their network was all CDMA but those phones had to have two radio antennas. They started dropping the second antenna in 2014 as their LTE network was improving. I had a Droid Turbo back then and it was a bit of an issue when they introduced the phone with one antenna and no VoLTE capabilities so no simultaneous voice and data. It took them several months to roll VoLTE out in an update and even then it wasn't usable in my area because calls would drop whenever you lost the LTE signal. Someone please correct me if I didn't state that well?