1 / 41

Telecommunications, the Internet, & Wireless Technology

Telecommunications, the Internet, & Wireless Technology. MIS 205 LECTURES Faculty: MzF. Trends in Telecommunications. New hardware devices; new alternatives for business & non-business communications (e.g., the RIM Blackberry) Telecommunications deregulation encouraged competition

deannaconner
Download Presentation

Telecommunications, the Internet, & Wireless Technology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Telecommunications, the Internet, & Wireless Technology MIS 205 LECTURES Faculty: MzF

  2. Trends in Telecommunications • New hardware devices; new alternatives for business & non-business communications (e.g., the RIM Blackberry) • Telecommunications deregulation encouraged competition • Dominance of Internet technologies in voice, data, & video communications • High-speed broadband connections to homes & businesses • Growth in wireless telephone & wireless computer networks • Growing scope of communication-intense products (e.g., Internet telephony, mobile commerce) ADM2372, M Benyoucef, Fall'08

  3. Trends in Telecommunicationsimpact on business • Declining transaction costs • Declining agency costs • Increased agility • Higher quality management decisions • Declining geographical barriers • Declining time barriers (work 24/7) ADM2372, M Benyoucef, Fall'08

  4. ADM2372, M Benyoucef, Fall'08

  5. ADM2372, M Benyoucef, Fall'08

  6. ADM2372, M Benyoucef, Fall'08

  7. ADM2372, M Benyoucef, Fall'08

  8. ADM2372, M Benyoucef, Fall'08

  9. Components of a Simple Network Network: 2 or more connected computers NOS (Network Operating System): routes & manages communications on the network & coordinates network resources NIC: Network Interface Card Switch: filters & forwards data to specified locations within a network Router: send packets of data though different networks ADM2372, M Benyoucef, Fall'08

  10. Data Communicationswhat (1) • Data communication: the process of transferring data, information or commands between 2 computers or between a computer and a terminal • Data communication requires • Transmitter & receiver • Protocol: set of rules • Medium • Message Medium Transmitter Receiver Message Protocol Source: Davis & Benamati, Ecommerce basics, Addison Wesley, 2002, Page 36 ADM2372, M Benyoucef, Fall'08

  11. Data Communicationswhat (2) • Transmitter/Receiver • Computer, terminal, hardware in general • e.g., PC, Cell phone, PDA, Kiosk, cash register, etc. • Medium • Wired (cable) • Twisted pair of wires (phone) • Coaxial cable (cable TV) • Fiber-optic cable • etc. • Wireless • Radio (laptop with a wireless card, Wireless Fidelity - Wi-Fi) • Satellite • Infrared (wireless keyboard) ADM2372, M Benyoucef, Fall'08

  12. Data Communicationsfiber optic cables • Thin strands of clear glass fiber • Data is transformed into pulses of light and sent over the cable • trillions of bits per second • Faster, lighter, durable, expensive, hard to install • Harder to hack (harder to listen to pulses of light) • Often used as a backbone (i.e., to carry signals to distribution nodes) • Dense Wave Division Multiplexing (DWDM) • Next-generation optical network • Uses many colors (wavelengths) of light (up to 160)  even greater capacity ADM2372, M Benyoucef, Fall'08

  13. Data CommunicationsTCP/IP (1) • Transmission Control Protocol / Internet Protocol (TCP/IP) • The communications protocol of the Internet • In order for any computer to use the Internet, it must be equipped with the software that enables this protocol • TCP/IP is based on “packet switching” - i.e., dividing messages into packets and sending each one individually ADM2372, M Benyoucef, Fall'08

  14. Data CommunicationsTCP/IP (2) - packet switching Packet switching: Technology that breaks blocks of data into fixed bundles and routes them in the most economical way through any available channel. Packets are reassembled once they reach their destination ADM2372, M Benyoucef, Fall'08

  15. Data CommunicationsTCP/IP (3) • IP (Internet Protocol) • Specifies the format of packets & addressing scheme • Addresses a packet and drops it in the system • TCP (Transmission Control Protocol) • Enables two hosts to establish a connection for a period of time to exchange data • Guarantees that packets are delivered in the same order in which they were sent ADM2372, M Benyoucef, Fall'08

  16. Data Communicationsvoice over IP (1) • Uses IP (Internet protocol) to deliver voice in digital form • Based on “packet switching” (instead of “circuit switching” used in regular telephone communications) • Low cost • Some delay in transmission (compared to circuit switching)  low sound quality • If high bandwidth  better sound quality ADM2372, M Benyoucef, Fall'08

  17. Data Communicationsvoice over IP (2) 3 2 4 1 5 ADM2372, M Benyoucef, Fall'08

  18. Data Communicationsbandwidth (1) • Bandwidth • Measures the amount of data a medium can transmit in a given period of time • bps (bits per second) • Kbps, Mbps or Gbps • K (1000), M (1 million), G (1 billion) • Baseband: one line, one channel • most local communications • Broadband: one line, simultaneous channels • DSL (Digital Subscriber Line) • Bell • Cable • Rogers ADM2372, M Benyoucef, Fall'08

  19. Data Communicationsmodem (1) • Analog signal • Continuous waveform • Voicecommunications • Digital signal • Discrete waveform • Two states: 0 and 1 • On-off electrical pulses • Data communications ADM2372, M Benyoucef, Fall'08

  20. Data Communicationsmodem (2) • Modem: MOdulation / DEModulation • Translates digital   analog ADM2372, M Benyoucef, Fall'08

  21. Networkswhat • A network • consists of two or more computers or other intelligent devices linked by communication lines (wired or wireless) • each device is called a node • examples of networks • 2 computers sharing a printer • the Internet ADM2372, M Benyoucef, Fall'08

  22. Server Wiring Closet Wiring Closet Floor 1 Floor 2 Basement NetworksLAN • LAN (Local Area Network) • Group of interconnected computers or workstations located in close proximity (e.g., within the same building) ADM2372, M Benyoucef, Fall'08

  23. NetworksWAN • WAN (Wide Area Network) • Network of networks • Links geographically distributed computers • Uses broadband public communication services • There is a need to boost and filter the signal • Examples of WANs • Internet, Intranet, Extranet ADM2372, M Benyoucef, Fall'08

  24. Networksclient / server (1) • Server: a computer that controls access to shared resources • powerful processor, large memory, large amount of secondary storage • Server hardware (i.e., Dell, IBM, …) • without server software, it is just a client workstation • Server software (MS Server, …) • turns the computer it runs on into a server • Clients • all the other nodes of the network ADM2372, M Benyoucef, Fall'08

  25. File System Peer-to-Peer File System Peer File System Peer Peer Networksclient / server (2) Server Printer Client Client File System Client/Server Client Client ADM2372, M Benyoucef, Fall'08

  26. NetworksInternet, extranet, intranet Internet extranet intranet ADM2372, M Benyoucef, Fall'08

  27. NetworksInternet (1) • The Internet is a public, global communications network that provides direct connectivity to anyone • over a LAN via an ISP (Internet Service Provider) or • directly via an ISP ISP: Internet Service Provider LAN: Local Area Network T1 Line: High-speed telephone line Source: http://computer.howstuffworks.com/web-server3.htm ADM2372, M Benyoucef, Fall'08

  28. NetworksInternet (2) • Strategic significance of the Internet • easily accessible • makes communications possible by using protocols • cost-efficient transfer of data • extensive reach + standardization  well suited for conducting business ADM2372, M Benyoucef, Fall'08

  29. Networks Intranet (1) • Corporate LAN or WAN that uses Internet technology • Secured behind company’s firewalls • Provides Internet capabilities such as • search engines, browsing, tools for communication & collaboration, etc. • The cost of converting an existing network system to an intranet is relatively low • Employees can get out on the Internet easily • Outsiders cannot get into the intranet ADM2372, M Benyoucef, Fall'08

  30. Networks Intranet (2) Server Client Internet Intranet Firewall E-mail Server Web Server Data base ADM2372, M Benyoucef, Fall'08

  31. Networks Firewall • Firewall: hardware & software that isolate the company’s intranet from the internet • Controls external access to the company’s servers • Most firewalls work by screening packets • Examples • Only allow packets originating from inside the company • Accept http but no ftp or telnet • Reject MP3 files and adult content ADM2372, M Benyoucef, Fall'08

  32. Networks VPN • Virtual Private Network • Provides secure transport of private communications over the public Internet • Less expensive, more flexible, greater bandwidth than non-IP networks • Creates tunnels of secured data flows using encryption • if intercepted, messages cannot be interpreted Internet Point B Point A ADM2372, M Benyoucef, Fall'08

  33. What is encryption? Encrypt Cipher Text Clear Text Sender Decrypt Cipher Text Clear Text Receiver • Secret Key encryption • A single key, known to both parties ADM2372, M Benyoucef, Fall'08

  34. What is encryption? A simple Caesar-shift substitution Cipher Plain text ATTACK AT DAWN ABCDEFGHIJKLMNOPQRSTUVWXYZ BCDEFGHIJKLMNOPQRSTUVWXYZA BUUBDL BU EBXO Base alphabet Shift one letter Cipher text [ Source: E-commerce Basics, by Davis & Benamati, Addison Wesley, 2003 ] ADM2372, M Benyoucef, Fall'08

  35. NetworksExtranet • Network that uses a VPN to link intranets in different locations over the Internet; an “extended intranet” • The protected environment of an extranet allows partners to collaborate & share info securely ADM2372, M Benyoucef, Fall'08

  36. The WWW (1) • Before 1990 • E-mail, FTP, telnet • Text based • UNIX commands • 1993: Mosaic • First browser • User friendly, graphical interface • Point & click • Will later become Netscape • 1995: Netscape went public • The WWW (World Wide Web): standardized protocols for creating, naming, linking & accessing Internet content ADM2372, M Benyoucef, Fall'08

  37. The WWW (2) Browser • Browser • software that runs on the client’s computer, requests & displays web pages • Web server • software that runs on the host computer and manages web pages • Application server • software that manages the interaction between the web server and the organization’s Information systems Internet Web Server Application Server Organizational Information Systems: Applications & Databases ADM2372, M Benyoucef, Fall'08

  38. The WWW (3) • URL (Uniform Resource Locator) • the address of a resource on the World Wide Web http://www.uottawa.ca Top level domain (others: com, org, UK, …) Local domain (others: bell, umontreal, etc.) Hypertext Transfer Protocol: rules used for exchanging web pages between the browser and the web server. Conventional name for the public web server, name of the program that runs on the host ADM2372, M Benyoucef, Fall'08

  39. The WWW (4) LAN Server Browser 1 7 2 6 Internet Client workstation 3 5 4 Web Server Web pages Downloading a web page Host Computer ADM2372, M Benyoucef, Fall'08

  40. The Wireless RevolutionBluetooth • A wireless networking standard for creating Personal Area Networks (PAN) • Links devices within a 10 meter range • Uses low power radio based communication at up to 722 Mbps ADM2372, M Benyoucef, Fall'08

  41. The Wireless RevolutionWi-Fi (Wireless Fidelity) • For wireless LANs • 54Mbps (10 to 30 meters range) • 11Mbps (30 to 50 meters range) • Security issues • Possibility of interferences (from wireless phones, other wireless LANs, etc.) • WiMax (Worldwide Interoperability for Microwave Access) • Range: up to 50 kilometers • Speed: up to 75 Mbps ADM2372, M Benyoucef, Fall'08

More Related