EMERGENCY NOTICE SYSTEM AND ITS EMERGENCY NOTICE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an emergency notice system and its emergency notice device that can transmit audio in several seconds from a transmission operation before transmission of video. SOLUTION: The emergency notice system is configured such that the emergency notice devices (10, 12) transmit audio information as audio service information through one of channels of a digital public line (24) and transmit video information as unrestricted digital information through other channel of the digital public line and receivers (30, 32) receive and output (reproduce) the audio information sent through the one channel and receive and output (reproduce) the video information sent through the other channel.