| 摘要 |
PURPOSE:To simplify the constitution by using a signal in a voice band handled by a telephone exchange such as a PB signal as a subscriber line signal for a broad band area exchange and using an existing telephone exchange as a subscriber line signal route and a voice signal route of the broad band area exchange. CONSTITUTION:A video signal is communicated between video transmitter- receiver 5 via a broad band area channel 1, and a voice signal is communicated through a route of telephone set of telephone number AAAA-telephone exchange 12-signal transmitter-receiver 10a of telephone number CCCC-voice channel 11-signal transmitter-receiver 10b of telephone number DDDD-telephone exchange 12-telephone set of telephone number BBBB. Then the television telephone communication is executed. Thus, the existing telephone exchange is used for the subscriber line signal route and the voice route of the broad band area exchange and the telephone set is used for the signal transmitterreceiver of the broad band area exchange system and the voice transmitterreceiver. Thus, a function multiplexing/demultiplexing each signal of speaker, microphone and key pad is not required in the terminal equipment and the subscriber line terminator such as speaker, microphone and key pad.
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