| 摘要 |
PURPOSE:To prevent a fault of talking even when two sets of radio telephone sets are in use at a close distance by setting a channel used for discrimination at the revision of a set speech channel as the speech channel with priority. CONSTITUTION:A speech channel is set by discriminating whether or not channels of frequencies A, 2XA-C and (A+C)/2 are available, where A is the frequency of the speech channel and C is the frequency of the channel in use only at the start of the speech. Furthermore, the channel used for discrimination at the revision of the speech channel is set as a speech channel with priority. When the channel whose frequency is (A+C)/2 is discriminated to be an idle channel, it is discriminated that the set channel whose frequency is A is available of the speech channel, and the number information of the channel is stored in a channel memory circuit. When a prescribed time elapses afterward, whether or not the channel whose frequency is A is idle is discriminated. |
