| 摘要 |
PURPOSE:To mutually communicate with a terminal of another system by demodulating an up frequency signal from a terminal and by converting the oscillation frequency of the local oscillator into the local oscillation frequency which provides different down frequencies that can be received by a terminal device of another system. CONSTITUTION:When a particular terminal device 8a of a system uses an up frequency signal f2 to send out frequency converting information under a demand for mutual communication with a terminal device 8b of another system, a demodulator 18 demodulates the frequency converting information sent out and gives it to a CPU 20 via a serial data I/O 19. A CPU 20 then interpretes the frequency converting information received, controls conversion of the oscillation frequency of a PLL local oscillator 14 via a data I/O 21, and a mixer 15 execute frequency conversion of the up frequency signal f2 into a down frequency signal f10 of another system, and sends it out to the CATV route via a coupler 11, thereby causing the terminal device of another system having the function of demodulating a down frequency signal f10 to receive terminal information to establish mutual communication between terminals each belonging to different systems. |
