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Ch.16.5 Methods of Internet Access

Ch.16.5 Methods of Internet Access. A. Internet Sevice Provider (ISP). For accessing the Internet via a modem Offers users a communication software package for setting up a connection with the ISP server. Package includes: Username Password Other necessary information (IP address)

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Ch.16.5 Methods of Internet Access

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  1. Ch.16.5Methods of Internet Access

  2. A. Internet Sevice Provider (ISP) • For accessing the Internet via a modem • Offers users a communication software package for setting up a connection with the ISP server. • Package includes: • Username • Password • Other necessary information (IP address) • Data transmission speed: • 56Kbps-1000Mbps

  3. Some types of ISP • Access Providers • For users and small businesses • Examples: I-Cable, One2Free next G • Hosting ISPs • Provide email, FTP, and web-hosting services • Some include virtual machines, • Examples: 0101Host, HKWebHost • Free ISPs • Provide free of charge service • Display advertisements like commercial TV • Examples: RapidShare

  4. B. Dial-up Connection • Includes a dial-up modem or a telephone line • Charges are fixed or based on usage time • Data transmission speed: • Max: 56Kbps

  5. Advantages • Cheapest for infrequent Internet users • Required no new infrastructure • use only the telephone line

  6. Disadvantages • Slower connectivity than other forms of internet access • Occupies the usage of the phone line • Unstable Connection • Possible long-distance charges if no ISP is in your area

  7. Dialing into an ISP

  8. Computer (with web browser, email program & ISP package) Modem cable Home Modem Digital signal Analogue signal Telephone line Internet ISP ISP Modem Modem cable Digital signal

  9. C. Integrated Services Digital Network (ISDN) • Similar to dial-up connection • An ISDN modem is needed to be connected to the ISP Sever • Data is transmitted as digital signals • Data transmission speed: • Max. 128Kbps

  10. Advantages • Higher data transfer rate • Two telephone lines are used • More stable • less likely to be affected by surrounding interference

  11. Disadvantage • Higher setup cost then that of dial-up connection • An ISDN adapter is necessary

  12. Computer (with web browser, email program & ISP package) Modem cable ISDN Modem Digital signal Conventional telephone line Digital signal Internet ISP ISP Modem Modem cable Digital signal

  13. C. Broadband Connections • Refers to a telecommunications signal or device of greater bandwidth • A digital modem and a NIC are needed • Broadband systems for home user: • Asymmetric digital subscriber line • Symmetric digital subscriber line • Cable modem

  14. Asymmetric digital subscriber line (ADSL) • Broadband connection • Different uploading and downloading speed • Higher downloading speed: 1.5-9Mbps • Lower uploading speed: 16-640Kbps • Users do not upload frequently at that time

  15. Symmetric digital subscriber line (SDSL) • Broadband connection • For organizations hosting a server which the uploading speed is critical • Need to upload a large amount of data • Same uploading and downloading speed • Max.: 24Mbps

  16. Cable modem • Broadband connection • Users can share the broadband highway in nearby locations  data transmission speed reduced from 30Mbps to 1.5Mbps during peak hours

  17. D. T-carrier • Permanent connection between network server and ISP’s server, or between ISP networks  users can access to the Internet at any time • Types of carriers • T1: 1.54Mbps • T2: 6.31Mbps (4x T1) • T3: 44.7Mbps (28x T1)

  18. Leased line • Also known as a ‘Private Circuit’ • Between one provider and one customer, or between two customers • Connected by a symmetric telecommunication line (same upload and download speed) • Permanently connected (always active) • Charge is a fixed monthly fee • affected by the distance and the speed

  19. E. Wireless Internet Access 1. Wi-Fi hotspots • Sites that built in public areas E.g. shopping centres, restaurants, schools • Offers Internet access over wireless LAN through the use of router connected to an ISP within a range • Hotspots in government properties and public facilities are usually free (Open public network)

  20. Advantages • Support roaming (allows mobile users to move from an access point to another) • Free of charge when accessing to open public network

  21. Disadvantages • Easily affected by interference • Low security • Cannot avoid interception • Limited range of wireless network • Maximum: 45m indoor, 90m outdoor

  22. 2. Wireless Application Protocol (WAP) • For mobile phones • Support Internet and Web applications • E-mail • Sports results • News headlines • Data transmission speed: 10Kbps-153Kbps

  23. 3. General packet radio service (GPRS) • For 2G and 3G mobile phones • 2G: SMS, voice call • 3G: access to the Internet • Provides connection with a GPRS network card • Allows users to surf the WWW and use e-mail service • Max. data transmission speed: 115.2Kbps

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