The correct answer is: C. Half Duplex
A paging system is a two-way communication system that uses radio waves to send and receive short messages. The system consists of a central paging station and a number of paging receivers. The paging station sends out a signal that is picked up by the paging receivers. The receivers then display the message on a small screen or emit a sound.
Paging systems use half-duplex transmission, which means that only one party can transmit at a time. This is because the paging system uses a single frequency for both transmission and reception. When the paging station is transmitting, the paging receivers cannot transmit. When the paging receivers are transmitting, the paging station cannot transmit.
Half-duplex transmission is less efficient than full-duplex transmission, which allows both parties to transmit at the same time. However, half-duplex transmission is simpler and less expensive to implement.
Simplex transmission is a one-way communication system in which only one party can transmit. This is because the simplex system uses a single frequency for both transmission and reception. When the transmitter is transmitting, the receiver cannot transmit. When the receiver is transmitting, the transmitter cannot transmit.
Full-duplex transmission is a two-way communication system in which both parties can transmit at the same time. This is because the full-duplex system uses two frequencies, one for transmission and one for reception. When the transmitter is transmitting, the receiver can still receive. When the receiver is transmitting, the transmitter can still receive.
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