4 Digital communication

Question 1

Define bandwidth

Answer 1

The number of bits that can be carried by a connection per second

Question 2

Explain the impact of higher bandwidth on user experience

Answer 2

More data can be transferred every second
Makes uploads and downloads faster

Makes it possible to do things that require lots of data to be transferred in short time e.g. online gaming, video streaming

Question 3

Define buffer

Answer 3

An area of memeory used to store data, especially when streaming video

Question 4

Define latency

Answer 4

The amount of time it takes to send data between devices

Question 5

How can you identify latency?

Answer 5

By ‘pinging’ a domain
Sends a packet of data to a server and the packet of data is immediately returned by the server to the device
The ‘ping time’ is the amount of time it takes for the packet of data to make the return trip

Question 6

Explain how high latency impacts user experience

Answer 6

Events may lag and not resposive to user commands

Question 7

Describe the factors that affect speed and volume transfer

Answer 7

1. Transfer method (wired faster than wireless, can carry more frequencies - more bandwidth)
2. Interference (can interfere with wired and wireless signals)
3. Blockages (wall and furniture reduce strength of wireless signals - less bandwidth)
4. Distance

Question 8

What does LAN mean? Describe this type of network

Answer 8

Local area network which is used within a small geographical area

Question 9

What does WAN mean? Describe this type of network

Answer 9

Wide area network which is used within a large geographical area

Question 10

What does PAN mean? Describe this type of network

Answer 10

Personal area network which is a group of connected devices that are all near an individual user

Question 11

Why do WANs have slower transfer speeds?

Answer 11

Because of their wider reach

Question 12

Define tethering

Answer 12

Process of connecting a host device (smartphone, tablet) that uses a mobile broadband connection with one or more devices

Question 13

What technology do satellites use?

Answer 13

Radio waves

Question 14

What technology does broadcast use?

Answer 14

Radio waves

Question 15

What technology do wired methods use?

Answer 15

Electric signals

Question 16

What technology do wireless methods use?

Answer 16

Radio waves

Question 17

Define lag

Answer 17

When there is high latency in an online server so is unresponsive

Question 18

How do devices recieve the signals that satellites transmit?

Answer 18

Antennae

Question 19

State the benefits of satellite communication

Answer 19

Always available due to number of satellites
Cannot be affected by power shortages

Question 20

State the drawbacks of satellite communication

Answer 20

Doesn’t pass through solid objects
Affected by bad weather

Question 21

Give examples of uses of satellite communication

Answer 21

GPS for navigation aids
Television
Satellite telephones in remote areas
Military

Question 22

Define ethernet

Answer 22

A network connectivity standard that provides a way for computers to communicate

Question 23

What is the use of HDMI?

Answer 23

Digital video connections

Question 24

What is the use of S/PDIF?

Answer 24

Digital audio connections

Question 25

What is the use of Minijack?

Answer 25

Personal headphones

Question 26

What is the use of USB?

Answer 26

Storage transfer

Question 27

What is the use of Ethernet?

Answer 27

Networking (connect to wired networks)

Question 28

What is WI-FI?

Answer 28

Wireless technology used to connect devices to a network

Question 29

What is Bluetooth used for?

Answer 29

Transfer small files between devices

Question 30

Compare WI-FI and Bluetooth

Answer 30

1. Range is longer for WIFI
2. Bandwidth is higher for WIFI
3. Power is higher for WIFI
4. Security is higher for WIFI
5. WIFI can connect multiple devices at the same time, Bluetooth is limited (has to be paired)

Question 31

What is mobile broadband used for?

Answer 31

Provides internet access to mobile devices when WIFI signal is not available

Question 32

Define infra-red

Answer 32

a wireless mobile technology used for device communication over short range

In TV remote controls

Question 33

What are the drawbacks of infra-red?

Answer 33

Cannot carry as much data
Have a short range
Require no blockages
Affected by sunlight

Question 34

What is near-field communication?

Answer 34

Connection that enables short range communication between two electronic devices
Uses close proximity RFID (radio frequency identification) chips

Used in smartphones, payment cars, travel cards

Question 35

Compare wired and wireless connections in terms of cost and safety

Answer 35

Cost:
Wired - Cables are cheap
Wireless - No need to buy cables, devices have Bluetooth built in

Safety:
Wired - Safety hazard, could trip on wires
Wireless - Safer, however some people are worried about effect of radiation

Question 36

Compare wired and wireless connections in terms of speed and stability

Answer 36

Speed:
Wired - Faster as it is direct transfer/ connection
Wireless - Slower connection/ transfer of files

Stability:
Wired - Less affected by interference, stronger connection
Wireless - Lack of strong connection due to interference

Question 37

Compare wired and wireless connections in terms of portability and mess

Answer 37

Portability:
Wired - Less portable as wires have to be carried around
Wireless - Portable within signal range

Mess:
Wired - Messier, many wires
Wireless - Tidy

Question 38

Compare wired and wireless connections in terms of security and maintenance

Answer 38

Security:
Wired - Less vulnerable to security issues, direct connection
Wireless - Vulnerable to security issues, easier to intercept a wireless signal

Maintenance:
Wired - Wire can break overtime, can get damaged
Wireless - None