Cambridge O Level Computer Science · Syllabus 2210 · Data Transmission
Echo Check
What is Echo Check?
An echo check is an error-detection method in which the receiver sends a copy of the received data back to the sender, who compares it with the original; a difference shows that an error occurred.
This definition is part of the Data Transmission chapter in Cambridge O Level Computer Science.
Echo Check in context
An echo check works by sending the data back. The sender transmits the data; the receiver sends a copy of what it received back to the sender; the sender compares the returned copy with the data it originally sent. If the two are different, an error has occurred and the data can be transmitted again. The method is simple, but it costs a second transmission of the whole data, and a returned copy that matches does not prove that everything went perfectly.