1.3 Data Transmission Flashcards
What are the two types of physical data transmission?
Serial Transmission
Parallel Transmission
What is serial transmission?
When a single channel is used to transmit data one bit after another
What is parallel Transmission?
When multiple channels are used to transmit data so multiple bits can be sent at one time
What are the advantages and disadvantages to serial transmission?
Advantages
- Reliability - Each bit is transmitted after the pervious bit which means there is no interference between bits
- Cheaper- They are easier to set up and there is less hardware cost
- Longer Distance- The wires can be longer as there is less interference
Disadvantages
- Slower Transmission times- one bit is sent after the other meaning the transmission takes longer
What are the advantages and disadvantages to parallel transmission?
Advantages
- Fast Transmission times- Bits are sent along multiple channels which results in fast transmission times
Disadvantages
- Unreliable- The bits from different lanes interfere with one another which can lead to corruption
- Short Distance - There is too much interference for the data to be transmitted over long distances
- Expensive- the cost of wires and installation can be very pricy
What are the two types of serial transmission?
Synchronous
Asynchronous
What is synchronous serial transmission?
This is when transmitting and receiving are synced to a clock that allows for a stream of bits to be sent reliably.
- The transmission times are quicker as there are no stop start bits but syncronisation can be expensive
What is asynchronous serial transmissions and it’s advantage to synchronous?
This is when data is synchronised using ‘stop’ and ‘start’ bits to ensure the data is receives successfully. ‘0’ starts and ‘1’ stops
- This is more cost effective than synchronous because the devices to not need to be synchronised before hand
