| 摘要 |
PURPOSE:To omit a time division switch or a conference speech trunk for a control device and to simplify the hardware constitution and processing of the control device by executing man-to-man normal speech and conference speech on the basis of the same control. CONSTITUTION:When a communication channel CHi is arrived from a transmission line 1a, a telephone set 2a converts an analog voice signal A1 outputted from a voice terminal equipment 3a of the self-station into a PCM voice signal A2 and sends the signals A2 to a transmission line 1b through a communication channel CHj. When communication channels CHj, CHk are arrived from the transmission line 1a, PCM voice signals B2, C2 from voice terminal equipments 3b, 3c are inputted and added and the added signal is converted into an analog voice signal B1+C1, which is outputted to a voice terminal equipment 3a. Telephone sets 2b, 2c also execute similar operation and these operations are repeated, so that the control device 4 executes conference speech between respective telephone sets without using the time division switch and the conference trunk. |
