9.1 Communication Flashcards
What is a symbol in relation to communication?
A particular pattern of bits represented by a signal.
Define baud rate?
the number of signal changes in the medium per second.
Define bit rate?
The numbers of bits that are transmitted over the medium per second. (Bps)
how do you calculate bit rate?
Bit rate = baud rate * number of bits per signal
Define bandwidth?
The range of frequencies that a communication medium is capable of transmitting (hz)
Define latency?
The difference in time between an action being initialised and its effect being noticed (ms)
Define protocol?
Set of rules relating to communication between devices allowing devices made by different manufacturers in opposite ends of the world to communicate.
What are the two different ways that computers can transmit data between their different components?
Serially or parallel
How does serial data transmission work?
Data is sent on bit at a time over one communication line.
How does parallel data transmission work?
Numerous parallel communication lines send multiple bits between components simultaneously.
What is bad about parallel data transmission?
Over long distances and extreme cases skews can lead to bits from different pulses overlapping causing the corruption of data. They are also more expensive than serial wires.
What are the advantages of serial data transmission?
Doesn’t suffer from skew or crosstalk meaning it’s a more reliable communication method especially over long distances. they are also cheaper than parallel.
How does synchronous transmission work?
A clock signal shared by both the sender and the receiver, times when the signals are sent. The signals sent at regular intervals, will be received in the same order they were sent.
How asynchronous transmission work?
Start and stop bits are used to indicate the duration of transmission. The start and stop bits are opposites. Both the sender and receiver must use the same Baud rate. The sender and receiver must synchronise their clocks for the duration of data transmission.
what does the start bit do?
sent at the beginning of the transmission so that the receiver can prepare for the incoming data
what does a stop bit do?
Marks the end of the transmission
