| 摘要 |
PURPOSE:To prevent confusion caused by simultaneous utterance of many persons by giving a permission to transmission only to the specified number of terminal units out of terminal units that gave a transmission request signal. CONSTITUTION:Four terminal units 1-4 are connected mutually through a center node, and each terminal unit 1-4 is provided with a transmitting device T, a receiving device R and a controlling device C that makes giving and receiving of transmission request signals etc. between the center node 5. A speech controlling device 50 starts speech mode changing switches S1-S4, T1-T4, R1-R4 based on transmission request signals received from terminal units 1-4, and changes the speech mode of each terminal unit 1-4. At this time, only terminal units less than a specified number out of terminal units that gave transmission request are enabled to make simultaneous transmission. |
