Florida State Paramedic Test 2026 – 400 Free Practice Questions to Pass the Exam

A simplex system in communication is defined by its ability to transmit information in one mode only. This means that communication can occur in a single direction, where one party transmits information while the other party can only receive it, without the capacity to respond or send messages back at the same time. This unidirectional nature is a key characteristic of simplex systems.

For context, the other options describe different communication configurations. A system where transmission is simultaneous is indicative of a full-duplex system, which allows for two-way voice communication—something a simplex system does not support. Similarly, two-way voice communication directly contradicts the definition of simplex since it involves both parties being able to transmit and receive messages. Lastly, utilizing multiple frequencies is associated with more complex systems such as frequency-hopping spread spectrum or multi-channel systems, rather than the straightforward communication style of a simplex setup. Hence, the ability to transmit in one mode only distinctly captures the essence of a simplex communication system.