Digital Communication Flashcards
The speed of data transfer depends on:
Bandwidth
Latency
What is bandwidth?
The number of bits that can be carried by a connection in one secod
Impact of bandwidth on user experience:
Faster bandwidth means faster transfer of data per second.
Huge amounts of data can be transferred in a short time such as multiplayer online gaming or high definition video streaming
What is a buffer?
An area of memory where data is temporarily stored esp. when streaming video
How to avoid the buffer being empty?
Data has to be downloaded constantly, filling up the buffer at a rate faster than it is being emptied
What is latency?
The amount of time it takes to send data between devices
How can latency be identified?
By pinging a domain
Impact of latency on user experience:
High latency will cause a game to lag and seem unresponsive to the player’s command
High latency while watching live television will cause a delay in real-time events and video being received for playback
Factors affecting the speed and volume of data transfer:
Transfer method
Interference
Blockages
Distance
How are devices connected in a PAN?
Directly or through wireless access points
What is tethering?
The process of connecting a host device that uses a mobile broadband connection to other devices so they can use the host’s broadband connection too
Benefits and drawbacks of satellite communication:
Benefits:
- Always available
- Not affected by power shortages
Drawbacks:
- Can be affected by atmospheric conditions
- Do not pass through solid objects
Uses of satellite communication:
- GPS
- Television (DVB-S)
- Telephone
- Military (communication systems)
Uses of broadcast communication:
- Analogue TV and radio
- Digital TV
- Digital radio
Common wired connection types and their uses:
- HDMI
- S/PDIF
- Minijack
- USB
- Ethernet
Use of mobile broadband connection:
Provides internet access to mobile devices when a Wi-Fi signal is not available
Uses of NFC:
Payment cards
Travel cards
Smartphones
Points of comparison between wired and wireless devices:
Cost
Maintenance
Mess
Speed
Safety
Security
Stability
Portability
Broadband, Mobile broadband, and cellular network
Broadband provides fast access to the internet through a connection to an ISP
Mobile broadband provides high-speed wireless connectivity using a 3G/4G to connect to a mobile phone network (ISP)
