ICT

• More computers are using protocols
• It is via a network that we are able to communicate with one another
• The most widely used method of data communication is face-to-face (me talking to you in the classroom, having conversations among friends and family)
• Types of computer networks

  • Local Area Network (LAN)
  • Metropolitan Area Network (MAN)
  • Wide Area Network (WAN)
• Local Area Network (LAN)


  A network which uses cables or radio signals to link two or more computers in a limited area (usually one building/a group of buildings)
• Metropolitan Area Network (MAN)


  A regional network spanning the area of an average or large-sized city. An example of a MAN is a WiMax network. More local examples include "EPICNET" or "surfnow.wiki".
• Wide Area Network (WAN)


  A data communication network which connects multiple LANs or MANs over telecommunication lines, or wirelessly. Best example, the Internet.
• We also refer to a mobile network as a type of network, but its purpose is slightly different from the other three
• Mobile networks have revolutionized over the years, from 1st and 2nd generation (GSM/GPRS) to 5th generation
• In many countries, 4th generation mobile networking is the standard, also known as LTE
• There is a more recent generation, 5G, that is rolling out in some developed countries, such as the United States and the United Kingdom
• With each generation, the speed of data transmission gets much quicker
• The father of the cellphone
• Transmission media


  • Wired media
  • Wireless media
• Wired media


  Cables referred to as wired media, including coaxial cable, twisted pair cable and fibre optic cable
• Wireless media


  Radio waves referred to as wireless media, including satellite, microwave and infrared
• Bluetooth


  Trademarked name for popular wireless data transmission
• Wi-Fi


  Also known as wireless fidelity, a trademarked name for popular wireless data transmission
• Wired networking hardware devices


  • Network card/Network adapter
  • Hub
  • Switch
  • Router
• Network card/Network adapter


  Component that allows computers to connect to a network (wired or wireless)
• Hub

  A common connection point for devices in a network, containing multiple ports
• Switch

  A device that serves as a controller, enabling networked devices to talk to each other efficiently
• Router

  A physical appliance (most commonly with antennae) which passes (or routes) information between two or more networks
• Wireless communication technology is a modern alternative to traditional wired networking
• Wireless networks rely on wireless technologies, while wired networks rely on cables to connect digital devices together
• Internet

  A public, global network based on the TCP/IP protocol, which assigns every connected computer with a unique IP address so that computers on the same network can communicate and locate data
• Intranet

  A private computer network designed to meet the needs of a single company that is based on internet technology, not open to outside users
• Extranet

  An intranet which has been selectively opened to selected individuals or organizations
• Protocols

  • HyperText Transfer Protocol (HTTP)
  • File Transfer Protocol (FTP)
  • Voice over Internet Protocol (VoIP)
  • Bluetooth
  • Wi-Fi
• HyperText Transfer Protocol (HTTP)

  Used to request and transmit files, and open web pages over the internet and other networks
• File Transfer Protocol (FTP)

  Used to transfer files between servers and clients
• Voice over Internet Protocol (VoIP)

  The use of internet based technologies to transmit voice data over the internet
• Bluetooth

  Used to exchange data over short distances from fixed and mobile devices by using radio waves, enabled by means of an embedded chip and supporting software
• Wi-Fi

  Also known as wireless fidelity, a marketing term used by the Wi-Fi alliance (not for profit) that tests products to ensure that they are up to standard
• Programming languages


  Ways to classify them: language generation, language level
• Generations of programming language

  • First generation (machine language)
  • Second generation (assembly language)
• Machine language


  • What is considered the "native tongue" of computers
  • Early programmers wrote their programs using machine code
  • Each instruction contained the operation to be executed and the memory address of the data to be operated on, held as a binary number
• Advantages of machine language


  • No need to translate
  • Efficient use of memory & CPU
  • Faster execution rate then in other generations
• Disadvantages of machine language

  • Limited to one type of machine
  • Difficult to comprehend; codes need to be remembered
  • Difficult to debug
• Assembly language


  • Short words, known as mnemonics, were used to represent the operations to be performed
  • Memory addresses of data were operated on as decimal numbers as opposed to binary numbers