3. Data Transmission Flashcards
What is serial data transmission?
It sends data one bit at a time in sequence down the same data line
What are the advantages and disadvantages of serial data transmission?
A:
- less wires
- reduces cost and physical space
- consists of a simpler interface/circuit board
- can travel longer distances
D:
- speed of data relies on bit rate of the connection
What is parallel data transmission?
It uses multiples wires to send many bits simultaneously along separate lines
What are the advantages and disadvantages of parallel data transmission?
A:
- faster over short distances
- up to 32 bits can be transferred simultaneously
D:
- crosstalk
- timing issues (skew)
What is crosstalk?
Interference due to an induced current in wires, reducing signal quality. This happens because the wires are close to each other
What can worsen skew?
- longer distances
- faster speeds
When is serial transmission used?
- almost all medium to long range transfers
- connections to systems e.g. USB
When is parallel data transmission used?
very short range transfers e.g. buses
What is simplex data transmission?
When data is transferred in one direction only, no return data packets are allowed e.g. keyboards
What is half duplex data transmission?
When data can be sent in two directions but only in one at a time e.g. printers
What is full duplex data transmission?
When data can be sent in two directions simultaneously e.g. facetime
What is multiplexing?
When multiple signals are combined into one signal over a shared medium in order to increase speed and efficiency
What is bandwidth?
The total theoretical carrying capacity of a medium
