If you've paired your mobile phone to Glass, Glass acts as a Bluetooth headset for your phone and you'll be able to place and receive phone calls through Glass.
You can place a call by voice action to contacts that you've set up in Glass. For example, "OK glass, make a call to Tiffany Chen" will call Tiffany. Make sure that the contacts you've set up for Glass have phone numbers in their contact information.
When a call arrives, your screen will turn on and display the phone number that is calling. Tap your Glass touchpad to accept the call. Tap the touchpad again when your call is over to end the call.
A rising and falling chime indicates someone is calling you. Screen the phone number by glancing at the display. To answer the phone, tap the touchpad and select Accept. To reject a call, swipe down on the touchpad or tap the touchpad, swipe forward and select Decline.
To hang up, simply tap the touchpad and select Hang up. Alternatively, you can end the phone call from your mobile phone.