| 摘要 |
PURPOSE:To attain the effective use of a radio wave, by providing one set of master station and plural sets of slave stations using this master set in common, and limiting the time in call of a slave set during a calling by a call request of other slave sets other than in call, when forming a channel between the master station and one slave station by using the same radio frequency. CONSTITUTION:When a slave telephone set 100-2 hooks off while a master telephone set 1-1 and a slave telephone set 100-1 in call, a channel control section 54 of the slave telephone set 100-2 detects the off-hook and that the radio line is used by the other slave set, and transmits a call request signal to the master set for a short time automatically on a radio wave other than that for the call. When the master set receives this call request signal, the master set operates the time in call monitoring section 14 and transmits a signal to a channel release section 15 after 5min. Then, the disconnect section 15 instructs the disconnection of the line to a connection control section 3 after 10sec so as to disconnect the line during the call forcedly. A disconnection notice tone is transmitted from disconnection tone transmitting section 16 to a caller during this 10sec. |
