Which channels are used for transmitting on one frequency and receiving on another?

Duplex channels are designed to allow simultaneous transmission on one frequency while receiving on another. This functionality is often utilized in communication systems where two parties can talk and listen at the same time, enhancing the efficiency and effectiveness of communication.

In the context of maritime communication, duplex channels enable vessels to maintain continuous communication with other ships or shore stations without interruption, which is crucial for safety and coordination, especially in busy waterways. This is particularly beneficial in complex scenarios where quick responses are needed.

Other options refer to simplex channels, which only allow communication in one direction at a time, thus limiting the interaction to either sending or receiving, but not both simultaneously. The specific channel numbers mentioned either relate to particular communication uses or do not inherently describe duplex capabilities.