APPARATUS AND METHOD FOR REDUCING TELEPHONE CHANNEL POWER LOADING

摘要

APPARATUS AND METHOD FOR REDUCING CHANNEL POWER LOADING A conventional telephone system including terminal equipments interconnected by a communications channel typically employs a supervisory tone transmitted by each terminal equipment to indicate its idle condition. When the friction of idle terminal equipments is high, the total energy carried over the channel is determined substantially by these tones. The apparatus of the type disclosed herein, employed in association with each terminal equipment, effects a reduction in the channel power loading due to those tones. The apparatus includes circuit means for generating a control signal during the presence of the idle state supervisory tone being transmitted from or received by the associated terminal. Other circuit means respond to the control signal to cause the supervisory signal transmitted by the terminal into the channel to be attenuated by a fixed power ratio and to cause the supervisory signal received by the terminal from the channel to be amplified by the same fixed power ratio.