From the onset, the iPhone has supported common features such as mid-call switching to an incoming phone call, creating a conference call between multiple parties and more. These features extend to FaceTime, Apple’s solution for making audio and video calls over the Internet that bypass a carrier’s voice network.
In this tutorial, you will learn how to make a quick transition to a FaceTime call on your iPhone without hanging up on the current call.
How to transition a phone call to a FaceTime call on your iPhone
Step 1: Place a phone call on your iPhone or accept an incoming call.
Step 2: While on the call, tap the FaceTime button on the calling screen.
After a second or two, your iPhone will make a seamless transition from the current call on your carrier’s voice network to FaceTime as long as the device has an active network connection over Wi-Fi or a cellular data network.
Mid-call switching to FaceTime is useful if another party has an iOS device and you want to talk over FaceTime. I prefer to call contacts over FaceTime whenever possible because the audio is much crisper than standard voice calls.
Tip: When a phone call or a FaceTime Audio call comes in, you can also end the current call and accept the incoming call, accept the incoming call and put the current call on hold or decline the incoming call, just like you normally would.
FaceTime is supported on Wi-Fi and cellular connections. Call waiting during a FaceTime Audio call is supported on iOS 8 or later.
As a reminder, you can use FaceTime over Wi-Fi on the iPhone 4 or later, iPad 2 or later, iPad Pro, all iPad mini models and the fourth-generation iPod touch and later (the fifth-generation iPod touch supports FaceTime Audio calling).
On cellular-enabled iOS hardware, FaceTime is supported on the iPhone 4s or later and iPads from the third-generation iPad onward. Wi-Fi-only iOS devices require that your sign up with an email address in Settings → FaceTime.
Source | idownloadblog