| 摘要 |
A digital radio telephone system for establishing communications between a main unit and a sub unit and between a plurality sub units. The system includes a main unit and a plurality of sub units. In order to establish communications with a sub unit, a calling signal including the sub unit extension number is first sent through the main unit to the sub unit. If the sub unit corresponding to an extension number in the calling signal is available, a calling acceptable signal is transmitted by the sub unit. The main unit includes an extension number multiplexer which multiplexes a plurality of sub unit extension numbers into one calling signal. Therefore, a calling signal from the main unit and calling signals from a plurality of sub units are multiplexed (combined) into a single calling signal. The main unit need only transmit a single multiplexed calling signal instead of a plurality of individual calling signals to each sub unit.
|
