2.1 types and methods of data transmission Flashcards
how is data transmitted
broken down into packets
what is the structure of a packet
packet header, payload, trailer
what is in a packet header
destination address, packet number, originator’s address
what is in the payload of a packet
the actual data being transmitted
what is in the trailer of a packet
signals the end of the packet, error checking
what is the process of packet switching
- data broken down into packets
- each packet could take diff route
- router controls route packet takes
- packets may arrive out of order
- once last packet arrives, packets reordered
what are diff methods of data transmission
- serial
- parallel
- simplex
- half-duplex
- full-duplex
what is serial and parallel transmission
1 bit sent at a time, more than 1 bit sent at a time
what are advantages and disadvantages of serial
+ reliable over long distances (likelihood of bits being lost along the way is slim)
+ bits unlikely to be lost
+ bits arrive in order as transmitted one after another
- slower than parallel
what are advantages and disadvantages of parallel
+ faster than serial
- bits arrive out of order, must be rearranged
- expensive over long distances as require multiple wires
what is simplex
information is sent in one direction (unidirectional)
what is half-duplex
information is sent in both directions, however not at the same time
what is full-duplex
information sent in both directions at the same time
what are advantages and disadvantages of simplex
+ cost effective, only require one communication channel
+ easiest and most reliable
- only one way communication possible
- no way to verify is transmitted data has been received correctly
+/- of half-duplex
+ allow bidirectional communication
+ more efficient than simplex as channel can be used for both transmission and reception
+ less expensive than full duplex
- less reliable than full-duplex as both devices cannot transmit at same time
