Infrared telephone extension modulation system

摘要: A portable telephone or other signaling system features a remote unit responsive to operator voice and control signals modulate infrared emitting diodes with narrowband, FM low duty cycle pulses which are received by network operative demodulate the signals, connection transmit receive from network. The utilizes narrowband pulse modulation optimize use of battery power. further includes means for transmitting on-and-off hook indicia dialing same efficient, modulation. base receiving decoding in order identify audio apply them as well detect dial process connecting disconnecting Audio sent via loudspeaker region along ring signals.