Facsimile communication system

Abstract

Abstract PURPOSE:To perform a communication between analog terminals through a digital communication line without spreading a transmission band area and spoiling instantaneousness with small scale constitution by providing a modem for a terminal equipment to an analog facsimile terminal side in a digital transmission terminal station. CONSTITUTION:Each of digital transmission terminal stations 4 and 5 is equipped with a serial input/output port 42, an HDLC procedure control port 43, a memory 44, a CPU45 and a direct memory access controller (DMAC) 46 and a digital communication line 3 is connected to the port 43. Terminal modems 12 and 13 are provided at the line interface parts of terminals 1 and 2 side in the transmission terminal stations 4 and 5. The modem 12 demodulates a picture signal and a control signal received from the terminal 1 and the transmission terminal station 4 multiplexes the demodulation signal in packet or time-divisionally, transmitting it to the transmission terminal station 5. And at the modem 13, the above stated signal received from a transmission side is modulated again, and transmitted to the terminal 2. Thus, the transmission band area is reduced. Also, by transmitting bit by bit in volume the control signal in packeting it, the accumulation capacity for data requires only a small quantity and also, the instantaneousness can be maintained.

Inventors

• 👤 Keiichi Obara
• 👤 小原　敬一

Bibliographic Details