Galaxy S4 Active missing WiFi calling

[wykrot]

I've got unlocked S4 Active from AT&T and using it on T-Mobile (US). The phone is rooted. I am missing WiFi calling option (as AT&T does not offer that). Is there any way to install WiFi calling into S4 Active?
I have been searching internet for 2h and couldn't find any comments on this issue.
Thanks everyone!

 

[Rukbat]

Since the hardware's not there to do it, probably not.