Sorry, I think you have SVLTE and VoLTE backwards
SVLTE is specifically about voice over CDMA and data over LTE. The other major Verizon phones support it. (I have and use it on my Nexus, for example.)
Google SVLTE:
http://www.anandtech.com/show/6295/...ous-voice-and-lte-or-evdo-svlte-svdo-support-
http://en.wikipedia.org/wiki/LTE_(telecommunication)
etc.
It's okay. We all get things mixed up at times. No harm. No foul.
Yes, my early morning education on this did confused me. You're correct.
http://en.m.wikipedia.org/wiki/LTE_(telecommunication)
So let me see if I have this right now.
Probably all LTE GSM phones (gsm iPhone included) use CSFB, meaning switching down to WCDMA for voice and data simultaneously.
Most Verizon phones use SVLTE, meaning two radios and two antennas, one for LTE data and the other for CDMA voice. And this is more power hungry given the duplication involved.
When the carrier network fully supports VoLTE, then both Verizon and ATT phones could operate the same way. Voice and data over LTE.
So I guess that Apple, having the desire to 1) make only one antenna based hardware design ( suspecting that the same chip is used in all frequency model differences today), and 2) not have a battery drain or expense difference between GSM and CDMA models, is betting on the longer term development of VoLTE leaving CDMA users in the lurch???
Probably mainly the first reason. Okay I get it now. I'm glad I started out with GSM in the US. Because I do like iPhones and data and voice working at the same time.
Regarding wifi and BT. I haven't really noticed that affect, but really haven't looked for it either. With the move to BT based speakers and of course wifi based music sources, this has to be done properly. I guess buffering etc is handling that.
Thanks for the clarification.