| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus capable of properly and quickly broadcasting emergency information such as disaster information and disaster prevention information when broadcasting takes place in a closed space. SOLUTION: When there is no problem in a tunnel, a digital broadcast receiving wave is retransmitted to the inside of the tunnel. At this time, retransmission signal leakage is prevented by terminal resistances 161, 162 to avoid adverse effects to the digital broadcast wave outside of the tunnel. When an accident occurs in the tunnel, sensors 181 to 183 detect it and a monitoring center 19 issues an emergency operation direction to an emergency broadcast facility 20. Concurrently, the emergency broadcast facility 20 stops receiving wave retransmission, broadcasts emergency information in the tunnel, controls transmission antennas 171, 172 for broadcast signal transmission and broadcasts emergency information near the entrance and exit of the tunnel. COPYRIGHT: (C)2007,JPO&INPIT |
