Networks: Data Transmission Flashcards
Serial Transmission?
Sends and receives data one but at a time.
Parallel Transmission?
Uses more wires to send bits simultaneously.
Advantage(s) of Parallel.
Capable of transmitting data faster.
Disadvantage(s) of Parallel.
Un-reliable over longer distances.
Expensive due to the large amount of wires.
Synchronous Transmission?
Data is transferred at regular intervals
This is controlled by the system clock which
synchronises the transmission with each ‘pulse’
Often used with parallel transmission
Useful for real-time data e.g. video messaging,
online games
Asynchronous Transmission?
Uses start and stop bits to synchronise the
transmitting and receiving devices temporarily.
It does this with the use of start and stop bits.
How does Asynchronous Transmission work?
The start bit causes the receiver to
synchronise its clock to the same rate as the
sender.
Both devices must already have agreed on how
many bits of data will follow.
The stop bit tells the receiving computer
that the data has arrived. The receiver can
then process those bits.
If there is more data, another start bit will
be sent and the cycle continues.
The sender’s computer sends the data as soon
as it is available rather than waiting for
the clock pulse.
Bandwidth?
The maximum amount of data that can be transmitted
at the same time.
Latency?
The difference in time between an action being initiated and its effect being noticed.
Protocol?
An agreed set of rules computers use to communicate.
