2.1 types and methods of data transmission Flashcards
how is data transmitted
- broken down
- into packets
describe the structure of a packet
- packet header
- payload
- trailer
what does packet header contain
- contain originator/destination IP address
- sequence number of packet
what does packet payload contain
actual data
what does packet trailer contain
- signals end of packet
- error checking methods
describe the process of packet switching
- data broken down into packets
- each packet could take diff route
- router control route packet takes
- packets may arrive out of order
- once last packet arrives, reordered
methods of transmission
- serial
- parallel
- simplex
- half-duplex
- full-duplex
describe simplex data transmission
bits travel in one direction only
describe half-duplex data transmission
- bits travel in both directions
- but not at same time
describe full-duplex transmission
- in both directions
- simultaneously
describe serial data tranmission
data sent one bit at a time over single wire
describe parallel data transmission
data of several bits sent down several wires at same time
advantages of serial data transmission
- better for longer distances
- cheaper
disadvantages of serial data transmission
- slower
advantages of parallel data transmission
- better for short distances
- faster than serial
- used when speed is necessary
disadvantages of parallel data transmission
- expensive (more hardware required)
what does USB stand for
universal serial bus
describe USB
asynchronous serial data transmission method
advantages of USB
- devices automatically detected
- drivers loaded for communication
- cable connecter fit in only one way: prevent incorrect connection and ensure compatible data tranmission
- standardised
disadvantages of USB
- max cable length roughly 5m (not suitable for long distance)
- older versions have limited transmission rates
- v old standards may not be supported in near future
