Simplex vs Half Duplex: Key Differences & When to Use
Simplex sends data in one direction only—like a radio broadcast—while half duplex lets both sides speak but not simultaneously, like walkie-talkies.
People confuse them because both involve one path. Yet Simplex is like shouting from a stage, while half duplex is like passing a mic back and forth; if you’ve ever talked over someone on a Zoom call, you’ve felt the awkward pause of half duplex.
Key Differences
Simplex: one-way, always transmitting, no feedback. Half duplex: two-way, one-at-a-time, requires turn-taking. Simplex uses less hardware and power; half duplex needs coordination to avoid collision.
Which One Should You Choose?
Pick Simplex for sensors, TV broadcasts, or doorbells. Choose half duplex for walkie-talkies, legacy CB radios, or budget Wi-Fi extenders where simultaneous chatter isn’t worth the extra cost.
Can Simplex ever receive?
No; it’s transmit-only, so no receiving path exists.
Is Wi-Fi full or half duplex?
Modern Wi-Fi is mostly full duplex via MIMO, but cheap range extenders may drop to half.
Why do cheap intercoms cut each other off?
They run half duplex, so only one side can speak at a time, creating awkward overlaps.