| 摘要 |
PURPOSE: To simultaneously transmit/receive data and voices by transmitting a supervisory packet by switching data transmission into voice superimpose mode when a transmitter/receiver is picked up, and simulating ring/ring-back for a remote telephone. CONSTITUTION: A personal computer 10 controls a system and communicates with respective remote devices through a standard telephone line 30 by using a local device 20 having a hand set, MODEM and digital telephone function. These respective devices are facsimile equipment 60, personal computer 80 connected with a MODEM 70, telephone 90 and personal computer 10a connected with a device 20a having the same function as the device 20. When the hand set is picked up, the device 20 transmits the supervisory packet, the data transmission mode is turned into voice data superimpose mode, and the telephone 90 and device 20 simulate ring/ring-back. Thus, a user knows a call or a response and during data communication, voices can be simultaneously exchanged with the other telephone 90 or the other device. |
