Deck 1

Question 1

What is Simplex Communication ?

Answer 1

A Communication channel where information is sent in one direction only.

Question 2

What is duplex communication ?

Answer 2

A communication channel where information can be sent in both directions.

Question 3

What is half duplex communication ?

Answer 3

A communication channel where information can be sent in both directions but only one direction at a time. (e.g walkie talkies)

Question 4

What is forward error correction ?

Answer 4

A method of error control in data transmission where the transmitter will send redundant data and the receiver only recognises the data that has no errors.

Question 5

What is Automatic Repeat Request (ARQ) ?

Answer 5

ARQ is a method of error control in data transmission where the receiver will detect if there is an error in the data packet and will notify the transmitter whether they sent a data packet with no errors or one without errors. In the event there is an error it will discard the packet and request another one.

Question 6

What are the advantages of Forward Error Correction (FEC) ?

Answer 6

1. Reduces the number of transmission errors.
2. Extends the operating range.
3. Reduces the power requirement for communication systems.

Question 7

What are the advantages of Automatic Repeat Request (ARQ) ?

Answer 7

1. Requires simple decoding mechanisms.
2. Requires less redundancy.
3. It is very adaptive in the sense that information is re transmitted when there is an error.

Question 8

What is XOR logic ?

Answer 8

If 2 values differ then the output is HIGH but if they’re the same the output is LOW.