Generated events let you evaluate what happens to the currently running application when a typically unplanned event occurs, such as an incoming call or a lost network signal.
To generate one of these circumstances
From the Emulator menu bar, navigate to Tools > Generate Event
Select one of the following:
Incoming call - Simulates an incoming call as in the figure above. This event does not play ring tones or vibrate the phone image to behave like a real device.
No signal - Simulates a device that loses the signal from a network. This state remains until you turn it off.
When a no signal event has been generated, the screen below appears:
Figure: No signal