Data Transmission: Circuit Switching vs Packet Switching

What is an advantage of serial transmission over parallel transmission?

What is the main difference between simplex and half-duplex transmission?

Which type of transmission sends all bits in a byte simultaneously?

What is a benefit of using parallel transmission?

What is full-duplex transmission?

Why is it efficient to not send data where it is not required?

What is the main characteristic of circuit switching in a computer network?

What is an advantage of packet switching over circuit switching in terms of network failure?

What happens to packets in packet switching if they arrive out of order?

Why is packet switching preferred in terms of security?

What is the purpose of switching in a computer network?

What is a characteristic of packet switching in a computer network?

What is an advantage of packet switching in terms of data line usage?

What is the main difference between circuit switching and packet switching?

Data Transmission Modes

Circuit switching: a path is set up between the sender and receiver before transmission, and all data follows the same path, in order.
Circuit switching: the path cannot be used by any other data during transmission.

Packet Switching

Data is split into packets before transmission.
Each packet may be transmitted by different routes through the network.
Packets may arrive out of order and are reassembled on arrival.
Advantages of packet switching:
- Better security as it is very difficult to intercept and reconstruct packets.
- Makes more efficient use of data lines as there is no waiting during gaps.
- Less likely to be affected by network failure because multiple paths are used.

Switching in a Computer Network

Switching sends data along the appropriate path.
Switching prevents all the data being sent to all parts of the network.
It requires less bandwidth and is more efficient not to send data where it is not required.

Serial and Parallel Transmission

Serial transmission:
- Data is sent bit-by-bit along the same data line.
- Advantages:
  - Requires only two wires compared to 8 or 16 in parallel.
  - Can travel longer distances than parallel.
  - Simpler interface/circuit board.
Parallel transmission:
- All bits in a byte are sent simultaneously along separate data lines.
- Advantage: transmission is faster than serial transmission.

Data Transmission Directions

Simplex: data transmission is possible in one direction only along a computer network/pathway/cable.
Half-duplex: data can be sent in either direction, but only in one direction at a time.
Full-duplex: data can be sent in either direction, in both directions at the same time/simultaneously.

Compare and contrast circuit switching and packet switching in computer networks, highlighting the advantages of packet switching. Practice with past paper questions from Jan 2012.