| 摘要 |
PROBLEM TO BE SOLVED: To surely insure data communication with low power even under a bad condition and to reduce the cost of the entire system by increasing and decreasing the number of channels, transmission cells, etc., in accordance with the communication state of a radio link due to rainfall, etc. SOLUTION: A controller 11 of a master station 1 controls a multiplexing device 3 and increases and decreases the number of channels that are subjected to time division multiplexing in accordance with the communication state of a radio link RF. The transmission rate of a multiple signal to be outputted to a modulator 5 is made 1/several, a needed exclusive band is made narrow and the density of frequency power is relatively made high by reducing the number of channels if a communication state is bad. A channel to be multiplexed is selected, based on a flag showing priority that is attached to the header information of each channel data. It is possible to surely transmit a channel that surely selects high SN ratio by means of the same transmission power and a high output is not needed uselessly even when a communication state is bad by adjusting the number of channels of transmission data in accordance with the communication state. |
