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Introduction to ICT and Programming

Introduction to ICT and Programming

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Introduction to ICT and Programming

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  1. Introduction to ICT and Programming Lecture # 3 : Internet & World Wide Web

  2. The World of The Internet

  3. The Internet & the World Wide Web Exploring Cyberspace • 2.1 Choosing Your Internet Access Device & Physical Connection: The Quest for Broadband • 2.2 Choosing Your Internet Service Provider (ISP) • 2.3 Sending & Receiving E-Mail • 2.4 The World Wide Web • 2.5 The Online Gold Mine: More Internet Resources, Your Personal Cyberspace, E-Commerce, & the E-conomy

  4. 2.1 Choosing Your Internet Access Device & Physical Connection • This section discusses the different technologies used to connect individuals to the internet including: • 1. Access device: a personal computer with a modem • 2. Physical connection: a telephone line

  5. Physical connection • The wired or wireless means of connecting to the Internet.

  6. Data Transmission Rates • Data is transmitted in bits per second. • bps stands for bits per second. A bit is the smallest unit of information used by computers. A computer with an older modem might have a speed of 28,800 bps per second. • Kbps stands for kilobits per second. This is the most frequently used measure. • Mbps stands for megabits per second • Gbps stands for gigabits per second

  7. Bandwidth • - an expression of how much data can be sent through a communications channel in a given amount of time • Broadband - very high speed connection

  8. Download & Upload • Download - to transmit data from a remote computer to a local computer • Upload - to transmit data from a local computer to a remote computer

  9. Telephone (Dial-Up) Modem: Low Speed but Inexpensive & Widely Available • Modem - device that sends and receives data over telephone lines to and from computers • Most modems today have a maximum speed of 56 Kbps. Using a modem and phone line to establish a connection to the Internet is called making a dial-up connection.

  10. High-Speed Phone Lines: More Expensive but Available in Most Cities • Integrated Services Digital network (ISDN) - hardware and software that allows voice, video, and data to be communicated over traditional copper-wire telephone lines. Speeds up to 128 kbps. • Digital Subscriber Line (DSL) - also uses regular phone lines but much faster than ISDN. Download speeds 1.5 – 8.4 Mbps • T1 - a traditional trunk line that carries 24 normal telephone circuits and has a transmission rate of 1.5 Mbps

  11. High-Speed Lines Cable : Close Competitor to DSL Speeds up to 10 Mbps Fiber Optics: Can support speeds up to 2 Gbps

  12. Wireless Systems: Satellite & Other Through-the-Air Connections • Satellite: With a pizza-size satellite dish on your roof, you can receive data at the rate of 400 Kbps from a communications satellite, a space station that transmits radio waves called microwaves from earth-based stations. • Other wireless connections:In urban areas, some businesses are using radio waves transmitted between towers that handle cellular phone calls, which can send data at up to 155 Mbps.

  13. Thank you • Thank you