| 摘要 |
PROBLEM TO BE SOLVED: To maintain communication with all slave units while reducing radio wave interferences to the other wireless communication system as much as possible in the case that wireless communication is performed with a plurality of slave units simultaneously.SOLUTION: A transmission power controller 102a performs transmission power control at a timing when all slave units are placed on a charging base. The transmission power controller 102a cancels the transmission power control readily after a minimum value of an RSSI level stored in a memory part 103 is eliminated. When an RSSI level other than the minimum value is eliminated, the transmission power controller 102a cancels the transmission power control in the case that an RSSI level of a sound signal of the slave unit 2 becomes a reception power reference value of the RSSI level or less. |
