What does "over" indicate at the end of a transmission?

The term "over" at the end of a transmission indicates that the speaker has finished their current communication and is expecting a response from the recipient. It is a convention used in radio communication to signal that the transmission is complete, but the conversation is not necessarily finished; the operator is inviting the other party to respond. This clarification is crucial for ensuring that both parties know when it is their turn to speak, thereby enhancing clarity and preventing misunderstandings in communication.

Using "over" helps establish the rhythm of the conversation, as it allows the receiving party to understand that they can now take the opportunity to reply or acknowledge the message. In contrast, the other options do not accurately reflect the purpose of the term. For example, stating that the conversation is still ongoing would be misleading, as "over" specifically indicates the end of that particular sentence or transmission. Similarly, "end of all communications" does not apply here because it suggests a cessation of dialogue, which is not intended with the use of "over." Lastly, the idea that the message needs to be repeated does not correlate with "over," as that would typically require a different term or acknowledgment to indicate a lack of clarity or understanding.