1.2.1 Data transmission Flashcards
Communication and internet technologies
What is data transmission?
It is the when data is sent from one device to another
How can data be transmitted? (cable etc)
- Cable
- Radio waves
Factors that should be considered when choosing a method of transmission:
- Direction of transmission
- Method of transmission
- Method of synchronisation
Define asynchronous:
Refers to data being transmitted in an agreed bit pattern, data bits grouped and sent with control bits. Receiver knows when data starts and ends so it doesn’t get mixed up.
Define synchronous:
Continuous stream of data and ensures sender and receiver are synchronized with each other since no gap. Fast but expensive.
Define serial transmission:
When data is sent one bit at a time over a single wire
Define parallel transmission:
When data is sent in multiple bits at same time over multiple wires.
Define simplex transmission:
Simplex is data going in one direction
Define half-duplex transmission:
Can go in both directions but not at same time
Define full-duplex transmission:
Can go in both directions at the same time
What is a Universal Serial Bus?
Asynchronous data transmission, consists of 4 wire shielded 2 for power/earth and two wires for data
What are some advantages of a USB?
Automatically detected
Fits one way
Industry standard
Different transmission rates
What are some disadvantages of a USB?
Max length 5m
Transmission rate less than 500 mb/s
