Originally Posted by paulker:
“Its not meant for privacy but convenience. All it means is that you can make or take calls at your computer or iPad (i think) even if your phone is elsewhere in your house or office. I suppose you could use headphones. No cellular network backend changes are needed. Al your doing is using your computer as a speaker and mic instead of the phone. Very handy. You can also make calls by clicking on a phone number on a website without picking up your iPhone.”
I think you're talking about convergence which is the ability to use the iPhone from a Mac or iPad.
The OP was talking about WiFi calling, something the US T-Mobile network has offered for a while, and is basically O2's TuGo built in. This solves signal issues when you have WiFi in a building but no cellular service your SMS and calls still get through.