Types and Methods of Data Transmission

Question 1

What are the three parts of a data packet?

Answer 1

Header, Payload and Trailer

Question 2

What does the header of a packet contain?

Answer 2

Source/ Originator’s IP address
Destination IP address
Packet Number

Question 3

What is the payload of a packet?

Answer 3

Actual data being transported.

Question 4

What does the trailer of a packet contain?

Answer 4

Additional security information
End of packet notification

Question 5

What is packet switching?

Answer 5

Packet switching is a method of sending and receiving data (packets) across a network.

Question 6

Describe the process of packet switching (5)

Answer 6

• Data is split and divided into packets
• Each packet takes a different route
• A router controls the route a packet takes
• Selecting the shortest available route
• Packets may arrive out of order
• Once the last packet has arrived, packets are reordered
• If a packet is missing it is requested again

Question 7

What is data transmission?

Answer 7

Data transmission is the process of transferring data from one device to another using a wired or wireless connection.

Question 8

What is serial data transmission?

Answer 8

A stream of bits is sent in sequence, one after the other over a single wire / channel.

Question 9

What is parallel data transmission?

Answer 9

Several bits of data is sent in sequence, one after the other across multiple wires at the same time.

Question 10

Advantages of Serial Data Transmission

Answer 10

• Data won’t be skewed / no crosstalk
• Less chance of interference - - Transmission speed is adequate

Question 11

Disadvantage of Serial Data Transmission

Answer 11

Slow transmission speed

Question 12

Advantage of parallel data transmission

Answer 12

Very fast transmission speed

Question 13

Disadvantages of parallel data transmission

Answer 13

Parallel data transmission is not suitable for long distances since the data can become skewed.
Parallel cables are not manufactured above 5m.

Question 14

Serial-Simplex

Answer 14

Data is transmitted one bit at a time in a single direction on one wire

Question 15

Serial-Half-duplex

Answer 15

Data can be transmitted in both directions on a single wire but only one bit at a time can be transmitted in one direction at a time

Question 16

Serial-Full-duplex

Answer 16

Data can be transmitted in both directions at the same time on a single wire one bit at a time

Question 17

Parallel-Simplex

Answer 17

Multiple wires transmit one bit at a time in one direction

Question 18

Parallel-Half-duplex

Answer 18

Multiple wires send multiple bits of data in both directions but only one direction at a time

Question 19

Parallel-Full-duplex

Answer 19

Multiple wires send multiple bits of data in both directions at the same time

Question 20

Advantage of simplex data transmission

Answer 20

Cheap as only one wire is used

Question 21

Disadvantages of simplex data transmission

Answer 21

Slow and expensive for bi-directional transmission (multiple wires)

Question 22

Advantages of half-duplex data transmission

Answer 22

Cheaper than simplex for bidirectional transmission (fewer wires).

Question 23

Advantages of full-duplex data transmission

Answer 23

Fast as data can travel in both directions simultaneously

Question 24

Disadvantages of half-duplex data transmission

Answer 24

Slow

Question 25

Disadvantages of full-duplex data transmission

Answer 25

Expensive

Question 26

USB (Universal Serial Bus) Advantages

Answer 26

- Devices are automatically detected and drivers are automatically loaded for communication - It cant be inserted the wrong way round - Backwards compatible - Universally Standardised - Powers the device for data transfer - Supports different transmission speeds

Question 27

USB (Universal Serial Bus) Disadvantage

Answer 27

The maximum cable length is roughly 5 meters meaning it cannot be used over long distances, limiting its use