Computer Science for IGCSE & O level - Data Transmission (Section 6 - No. 8)
How do echo checks identify errors?
By sending the data back to the sender.
By sending a parity bit along with the data.
By calculating a checksum on the data.
By encrypting the data before it is sent.
Giải thích
Echo checks work by having the receiver send the data back to the sender, comparing it to the original.