2.1 TYPES OF DIGITAL COMMUNICATION

Question 1

WHAT IS SATELLITE COMMUNICATION?

Answer 1

Transmits data and radio waves. Receives data from digital devices.

Question 2

HOW DO DIGITAL DEVICES RECEIVE RADIO SIGNALS?

Answer 2

Digital devices use antennae to receive radio signals that satellites transmit.

Question 3

WHAT ARE THE 4 USES OF SATELLITE COMMUNICATION?

Answer 3

1. GPS
2. TV
3. Telephone
4. Military

Question 4

HOW IS SATELLITE COMMUNICATION USED FOR GPS?

Answer 4

Navigation aids make use of GPS signals to calculate the exact location of a device.

Question 5

HOW MANY SATELLITES ARE ON EARTH AND HOW ARE THEY CONNECTED TO US?

Answer 5

24 satellites on earth. 12 in your range. 4 needed to locate.

Question 6

HOW IS SATELLITE COMMUNICATION USED FOR TV?

Answer 6

Video signals from broadcaster is transmitted through large antennae on earth to multiple satellites. Then the satellite broadcasts this signal back to earth. Set-top box deals with the rest.

Question 7

WHAT DOES A SET TOP BOX DO?

Answer 7

Decodes signal and converts it so it is ready to be sent to TV.

Question 8

HOW IS SATELLITE COMMUNICATION USED FOR A TELEPHONE?

Answer 8

People in rural areas make calls using satellite telephones.

Question 9

HOW IS SATELLITE COMMUNICATION USED FOR THE MILITARY?

Answer 9

The military use satellites for communication systems like global demand and control system.

Question 10

BENEFITS OF SATELLITE COMMUNICATION?

Answer 10

The system is always available because of the number of satellites.

Question 11

DRAWBACKS OF SATELLITE COMMUNICATION?

Answer 11

• Satellite signals do NOT pass through objects so it will not work in areas with tall buildings/tunnels.
• Can be affected by weather.

Question 12

WHAT IS BROADCAST COMMUNICATION?

Answer 12

Transmitters broadcast radio waves, TV signals, radio signals that are received by viewer’s antennae. Antenna sends signals through wire to TV/radio receiver which then converts it into image/audio.

Question 13

WHAT IS WIRED COMMUNICATION?

Answer 13

Uses cables to connect with each other, only uses electrical signals.

Question 14

WHAT ARE THE CONNECTION TYPES OF WIRED CONNECTION?

Answer 14

• HDMI
  -S/PDIF
  -MINI JACK
• USB
• ETHERNET

Question 15

WHAT IS HDMI USED FOR?

Answer 15

Used for digital video connection.

Question 16

WHAT IS S/PDIF USED FOR?

Answer 16

Used for digital audio connections.

Question 17

WHAT IS MINI JACK USED FOR?

Answer 17

Personal headphones.

Question 18

WHAT IS USB USED FOR?

Answer 18

Storage transfer

Question 19

WHAT IS ETHERNET USED FOR?

Answer 19

Used for networking

Question 20

WHAT IS ETHERNET?

Answer 20

Ethernet is network connectivity, providing a standard way to communicate for computers.

Question 21

WHAT IS WIRELESS COMMUNICATION?

Answer 21

Uses wireless radio waves connectivity to communicate to each other.

Question 22

WHAT ARE THE WAYS OF WIRELESS COMMUNICATION?

Answer 22

1. Wifi
2. Bluetooth
3. 3G +4G
4. Infra-red (IR)
5. Near-field communication (NFC)

Question 23

WHAT IS WIFI AND HOW IS IT USED?

Answer 23

WIFI is wireless technology connecting devices to a network. The network itself is connected to the internet.

Question 24

FEATURES OF WIFI?

Answer 24

• Long range
• High bandwidth
• High power
• High security
• Can connect multiple devices simultaneously

Question 25

WHAT IS BANDWIDTH?

Answer 25

Number of bits that can be carried by a connection in one second.

Question 26

WHAT IS BLUETOOTH?

Answer 26

When devices connect over small distances.

Question 27

FEATURES OF BLUETOOTH?

Answer 27

• Short range
• Low bandwidth
• Low power
• Low security
• Connects limited devices simultaneously (usually has to be paired)

Question 28

WHAT DOES 3G+ 4G DO?

Answer 28

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

Question 29

FEATURES OF INFRA-RED?

Answer 29

• Devices connect over short range
• Transmitters need to have a clear line of sight to receivers. Nothing can block the signal to the receivers, HAS TO TRAVEL IN STRAIGHT LINE.

Question 30

WHAT DOES NEAR-FIELD COMMUNICATION (NFC) DO?

Answer 30

Uses close proximity RFID (Radio Frequency Identification) chips (in SIM/credit cards).

Question 31

WHAT IS DEVICE-TO-DEVICE COMMUNICATION?

Answer 31

Wired/wireless connection between multiple devices.

Question 32

EXAMPLES OF DEVICE-TO-DEVICE COMMUNICATION?

Answer 32

• Phone + headphones –> minijack = audio played from phone to headphones.
• Camcorder + monitor –> HDMI = operate as security camera.

Question 33

WHAT ARE THE NETWORKS DIGITAL DEVICES CONNECT OVER?

Answer 33

1. Local Area Network (LAN)
2. Wide Area Network (WAN)
3. Personal Area Network (PAN)
4. Tethering

Question 34

HOW DOES LAN WORK?

Answer 34

LAN connects digital devices in a small geographical area - close together.

Question 35

HOW DOES WAN WORK?

Answer 35

Network spreading over a large geographical area. Connected over many satellites (many LANs). Distance issue - can be connected directly.

Question 36

USES OF WAN?

Answer 36

• National and international businesses
• Law enforcement agencies
• Health and education organisations
• Government departments

Question 37

HOW DOES A PAN WORK?

Answer 37

Group of connected devices all near to an individual user.

Question 38

EXAMPLE OF PAN?

Answer 38

Connecting a smartwatch to a smartphone.

Question 39

HOW DOES TETHERING WORK?

Answer 39

Connecting to a host device that uses mobile broadband connection with one or more devices. Lets other devices connect easily. Can be tethered wired/wireless.