4 Digital communication Flashcards
Define bandwidth
The number of bits that can be carried by a connection per second
Explain the impact of higher bandwidth on user experience
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
Define buffer
An area of memeory used to store data, especially when streaming video
Define latency
The amount of time it takes to send data between devices
How can you identify latency?
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
Explain how high latency impacts user experience
Events may lag and not resposive to user commands
Describe the factors that affect speed and volume transfer
- Transfer method (wired faster than wireless, can carry more frequencies - more bandwidth)
- Interference (can interfere with wired and wireless signals)
- Blockages (wall and furniture reduce strength of wireless signals - less bandwidth)
- Distance
What does LAN mean? Describe this type of network
Local area network which is used within a small geographical area
What does WAN mean? Describe this type of network
Wide area network which is used within a large geographical area
What does PAN mean? Describe this type of network
Personal area network which is a group of connected devices that are all near an individual user
Why do WANs have slower transfer speeds?
Because of their wider reach
Define tethering
Process of connecting a host device (smartphone, tablet) that uses a mobile broadband connection with one or more devices
What technology do satellites use?
Radio waves
What technology does broadcast use?
Radio waves
What technology do wired methods use?
Electric signals
What technology do wireless methods use?
Radio waves
Define lag
When there is high latency in an online server so is unresponsive
How do devices recieve the signals that satellites transmit?
Antennae
State the benefits of satellite communication
Always available due to number of satellites
Cannot be affected by power shortages
State the drawbacks of satellite communication
Doesn’t pass through solid objects
Affected by bad weather
Give examples of uses of satellite communication
GPS for navigation aids
Television
Satellite telephones in remote areas
Military
Define ethernet
A network connectivity standard that provides a way for computers to communicate
What is the use of HDMI?
Digital video connections
What is the use of S/PDIF?
Digital audio connections
What is the use of Minijack?
Personal headphones
What is the use of USB?
Storage transfer
What is the use of Ethernet?
Networking (connect to wired networks)
What is WI-FI?
Wireless technology used to connect devices to a network
What is Bluetooth used for?
Transfer small files between devices
Compare WI-FI and Bluetooth
- Range is longer for WIFI
- Bandwidth is higher for WIFI
- Power is higher for WIFI
- Security is higher for WIFI
- WIFI can connect multiple devices at the same time, Bluetooth is limited (has to be paired)
What is mobile broadband used for?
Provides internet access to mobile devices when WIFI signal is not available
Define infra-red
a wireless mobile technology used for device communication over short range
In TV remote controls
What are the drawbacks of infra-red?
Cannot carry as much data
Have a short range
Require no blockages
Affected by sunlight
What is near-field communication?
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
Compare wired and wireless connections in terms of cost and safety
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
Compare wired and wireless connections in terms of speed and stability
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
Compare wired and wireless connections in terms of portability and mess
Portability:
Wired - Less portable as wires have to be carried around
Wireless - Portable within signal range
Mess:
Wired - Messier, many wires
Wireless - Tidy
Compare wired and wireless connections in terms of security and maintenance
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
