Which of the following devices is an example of half-duplex communication?

Concept

A communication mode is classified by whether information can travel in one or both directions and, if it travels both ways, whether the two directions can be active simultaneously. In half-duplex communication, both ends can transmit and receive, but only one end transmits at a time.

Application

Walkie-talkies use a shared push-to-talk channel. One user presses the transmit button and speaks while the other user listens; the users then exchange roles to reply. Thus communication is bidirectional but not simultaneous.

Contrast and cross-check

• Radio broadcasting has a one-way station-to-receiver path, so it illustrates simplex communication.

• A conventional telephone call permits simultaneous two-way speech, so it illustrates full-duplex communication.

• Broadcast television has a one-way station-to-viewer path, so it illustrates simplex communication.

• Walkie-talkies permit both users to transmit, but turn-taking prevents simultaneous transmission; this matches the half-duplex rule.

Therefore, walkie-talkies are the half-duplex device among the given choices.