| 摘要 |
PURPOSE:To efficiently search an idle channel by preferentially selecting a speaking channel, which is used for the last speaking, as a speaking channel for sensing a carrier at the time of call origination/termination. CONSTITUTION:A control circuit 5 of a base unit, which receives the off-hook signal of a slave set, senses the carrier, which is stored in a RAM 7, of the speaking channel to be used. When no carrier is detected, a transmission channel is set as a control channel, and the report of the speaking channel to be used is transmitted to the slave set. When the carrier is detected at the speaking channel to be used, the control circuit 5 stores the other speaking channel in the RAM 7 and senses the carrier repeatedly 10 times. Thus, since the speaking channel used for the last speaking is preferentially selected as the speaking channel to sense the carrier at the time of call origination/termination, the speaking channel can be used suitably for an installation environment and speedily selected. |
