| 摘要 |
Communication between a first radio transmitter and receiver and a second radio transmitter and receiver is provided by a system repeater. Apparatus for each radio transmitter and receiver in the system establishes communication on a radio frequency channel selected from a plurality of such channels. When such apparatus is in an idle or receive mode, it causes the associated receiver to search the channels for a predetermined group tone or tones assigned to each receiver. When the predetermined group tone or tones are received on a channel, the arrangement enables the associated transmitter and receiver on that channel. When an arrangement is in a call originate or transmit mode, it causes the associated receiver to search for an idle or unused channel. When an idle channel is found, the apparatus enables the associated transmitter and receiver on that channel, and causes the transmitter to transmit a busy tone and the predetermined group tone or tones so as to enable the other transmitters and receivers of the predetermined group on that same channel. |
