| 摘要 |
PROBLEM TO BE SOLVED: To suppress the power consumption of the equipment from being increased by decreasing a transmission level when the number of subscribers using a channel exceeds a prescribed number and limiting the number of subscribers using the channel when a received electric field strength is decreased more than a prescribed strength. SOLUTION: A channel using subscriber number detection circuit 9 counts the number of subscribers using a channel. An automatic level control circuit 10 sends a control signal to a power amplifier 3 when the number of the subscribers using the channel exceeds a prescribed number N to reduce a transmission output of the amplifier 3 to a prescribed value. A reception input electric field strength detection circuit 11 detects it that the electric field strength reduces to a prescribed level due to rainfall or the like, the circuit 11 sends a control signal to a subscriber interface circuit 1 to limit the number of the subscribers using the channel to be a prescribed number N or below. A power supply voltage detection circuit 13 controls the channel using subscriber number detection circuit 9 to lower a point at which the transmission output reduction starts when the power supply, voltage is decreased from a prescribed voltage. |
