Data Transmission: Circuit Switching vs Packet Switching

Study Notes

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.

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 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 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.

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.