ICT data exchange

ICT data exchange

1. Transmission modes

   • Simplex- Is only a one way transmission of information eg radio
   • Half duplex- Two way transmission but only one at a time eg walkie talkies
   • Full duplex- Two way transmission at the same time eg mobile phones

2. Codec- codes and decodes analogue and digital signal... prepares sound and videos in data packets

3. Transmission methods

   • Wired
     • UTP/STP- unshielded twisted pair or shielded
     • Coaxial-copper bases wire cable+ layer of plastic insulation
     • Fibre Optic- thin glass rod which reflects light
   • Unwired
     • Infrared- short data transmission
     • Mictowave-short wavelength, high frequency
     • Satellite- data transmitted from earth to satellite

4. Ways data is exchanged

   • Serial- bits are transmitted one at a time over a single wire or channel...reduces costs...used over large distances
   • Parallel- a number of bits transmitted simultaneously over an equal number of wires or channels...rare due to costs... limited range
   • Packet swtiching- when data is sent across the internet they are broken into lots of parts called pieces eg webpages, emails, instant messages
     • Benefits- it is efficient to the network as there isn't any tied lines- easily get around parts of a network which are broken-good alternative to circuit switching

5. Wireless Networks

   • Components
     • Router-connects computers and other capable devices together to form a network
     • Access point-allows wireless devices to connect to a wired network
     • Wireless network adaptors-converts data into radio signal and the wireless receiver decodes it
   • Client side processing-use of instructions for the client and produced on a webpage e.g. roll over on a webpage
     • Benefits are speed and security and disadvantages are bowser specific and sped of computer
   • Server side processing-information submitted to a server which provides result in form of a webpage includes scripts that run on an internet web server
     • Benefits are efficiency, browser, independence and speed and disadvantages include security and overloading