Being trapped in the elevator may be the worst nightmare for many people, especially for those with claustrophobia. When the elevator gets stuck, the passengers tend to act impulsively such as forcing the door to open by strength, kicking the door or attempting to climb out. But the thing is that people sometimes just forget to use the emergency button on the control panel. The standard traditional elevator only supports analog copper wires as its intercom system. With the existing system, even when the maintenance company receives the system alarm first, they can not contact the passenger inside the cab remotely if the passenger fails to press the emergency button.