TELEPHONE COMMUNICATION SYSTEM

PROBLEM TO BE SOLVED: To provide a telephone communication system allowing a user to make a call with a telephone communication means connected to an optical communication path, irrespective of the conduction state of a commercial power source. SOLUTION: The telephone communication system comprises an optical fiber (31) laid down between an electric power company and a user of extra-high voltage power; optical termination boxes (33a, 33b) provided on each of the electric power company and the user of extra-high voltage power, and connected to an arbitrary core wire in the optical fiber (31) at both the ends of the core wire; an optical telephone relay devices (1a, 1b) connected to the optical termination boxes (33a, 33b) at both the ends of the arbitrary core wire in the optical fiber (31); and telephones (2a, 2b) connected to the optical telephone relays (1b, 1b). The optical telephone relay devices (1a, 1b) are each configured so that upon receiving optical signals from the core wire, the devices convert electric signals into electric signals and transmit them to the telephones (2a, 2b) connected to the optical telephone relay devices (1a, 1b). Upon receiving electric signals from the telephones (2a, 2b), the devices convert the received signals into optical signals and transmit the converted signals to the core wire. The optical telephone relay devices (1a, 1b) are provided with power source units (7a, 7b) for feeding power to the connected telephones (2a, 2b), respectively. COPYRIGHT: (C)2005,JPO&NCIPI