Cambridge IGCSE Computer Science Data transmission

Why is it important to check for errors when data is transmitted?

(a)  

Which of the following is NOT a reason for errors during data transmission?

• Interference

• Problems during packet switching

• Skewing of data

• High internet speed

Which of the following are ways data can be checked for errors during transmission?

• Parity checks

• Checksum

• Echo check

• All of the above

Name one method used to check for errors in data transmission.

(a)  

Find the parity bit for the byte: 1 1 0 1 1 0 1 0 1. What type of parity is being used?

(a)  

Find the parity bit for the byte: 1 1 1 1 1 1 1 1 0. What type of parity is being used?

(a)  

Fill in the blank: In the parity block method, a block of data is sent and the number of 1-bits is totalled horizontally and vertically. This method not only identifies that an error has occurred but also indicates (a)   .

What is a checksum?

• A method to check if data has been changed or corrupted following data transmission

• A type of barcode

• A way to encrypt data

• A method to compress data

Fill in the blank: The checksum is sent at the end of the (a)  

What is an echo check?

• A method where data is sent back to the sender to check for errors

• A way to encrypt data

• A type of barcode

• A method to compress data