11: Communication

Question 1

what is serial transmission

Answer 1

sending data one bit at a time over a single channel

Question 2

what is parallel transmission

Answer 2

sending multiple bits of data simultaneously

Question 3

when is serial transmission used

Answer 3

long haul communication

Question 4

when is parallel tranmission used

Answer 4

short range high speed connections

Question 5

give 2 advantages of serial transmission

Answer 5

• reliable over long distance - only one bit is sent at a time
• cheaper - physical size of cable is smaller and more flexible
• doesnt suffer from skew

Question 6

give 2 advantages of parallel tranmission

Answer 6

• lower latency
• high data transfer rates

Question 7

explain what skew is

Answer 7

• bits transmitted over different channels arrive at different times

Question 8

what are the 2 types of serial transmission

Answer 8

• synchronous transmission
• asynchronous transmission

Question 9

explain what synchronous transmission is

Answer 9

• data is transfered at regular intervals
• they are synchronised by a clock signal

Question 10

explain what asynchronous transmission is

Answer 10

• one character at a time with a start, stop and parity bit sent for each character
• data is sent in packets

Question 11

define bit rate

Answer 11

the number of bits transferred between devices per second

Question 13

define baud rate

Answer 13

number of times a signal in a communications channel changes state in a second

Question 14

what is meant by latency

Answer 14

the delay between an action being started and its effect being noticed

Question 15

what is a protocol

Answer 15

strict set of rules

Question 16

explain what a “handshake” is

Answer 16

when two devices exchange signals in order to set up a communication link

Question 17

define bandwidth

Answer 17

the maximum amount of data transfer over a single channel