| 摘要 |
PROBLEM TO BE SOLVED: To provide a radio communication system allowing each slave set accompanying a master set and plural external communication lines to communicate with each other with less effect of interference radio waves. SOLUTION: The master set 10 is connected with the plural external communication lines and executes bi-directional communication with plural slave sets (a telephone slave set 32, a FAX slave set 44, e.g.) by a time division system and a frequency hopping system. The plural slave sets are simultaneously connected with the external communication lines. Then, variable frequency oscillators (PLL circuits) are provided for the transmitter-receivers 34 and 48 of each slave set and each slave set executes frequency hopping while the other slave set communicates with the master set but not executes it at the same time with the master set. Thereby the PLL circuits of the slave sets do not need to have specially high performance so that the system is constructed inexpensively. When a transmitting amount and a receiving amount are not the same, the transmission/reception slot of a larger quantity is magnified. |
