Telecommunications and networks
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This document discusses telecommunications and networks. It describes components of telecommunications systems including computers, terminals, communication channels, and processors. It also compares different types of communication channels such as twisted wire, coaxial cable, fiber optic cable, microwave, and wireless transmission. Additionally, it examines local area networks (LANs), wide area networks (WANs), and network services such as packet switching, frame relay, and asynchronous transfer mode (ATM). The document concludes by looking at technologies that support e-commerce and e-business.
Telecommunications and networks
- 1. 8 TELECOMMUNICATIONS AND NETWORKS c h a p t e r
- 2. LEARNING OBJECTIVES DESCRIBE COMPONENTS OF TELECOMMUNICATIONS SYSTEM CALCULATE CAPACITY OF TELECOMMUNICATIONS CHANNELS & EVALUATE TRANSMISSION MEDIA COMPARE TYPES OF NETWORKS & NETWORK SERVICES *
- 3. LEARNING OBJECTIVES COMPARE ALTERNATIVE NETWORK SERVICES IDENTIFY APPLICATIONS FOR SUPPORTING ELECTRONIC COMMERCE, BUSINESS *
- 4. MANAGEMENT CHALLENGES TELECOMMUNICATIONS REVOLUTION COMPONENTS, FUNCTIONS OF TELECOMMUNICATIONS SYSTEM COMMUNICATIONS NETWORKS ELECTRONIC COMMERCE & ELECTRONIC BUSINESS TECHNOLOGIES *
- 5. MANAGEMENT CHALLENGES 1. MANAGING LOCAL AREA NETWORKS: Must be carefully administered, monitored, vulnerable to interruption, data loss, viruses 2. MANAGING BANDWIDTH: While costs per unit are dropping and capacity is growing, sudden demand can overwhelm system *
- 6. TELECOMMUNICATIONS COMMUNICATING INFORMATION VIA ELECTRONIC MEANS OVER SOME DISTANCE *
- 7. INFORMATION SUPERHIGHWAY NATIONAL / WORLDWIDE HIGH SPEED DIGITAL TELECOMMUNICATIONS ACCESSIBLE BY GENERAL PUBLIC *
- 8. SYSTEM COMPONENTS COMPUTERS TERMINALS: Input / output devices COMMUNICATIONS CHANNELS PROCESSORS: Modems, multiplexers, front-end processors COMMUNICATIONS SOFTWARE *
- 9. PROTOCOL RULES & PROCEDURES TO GOVERN TRANSMISSION BETWEEN COMPONENTS IN A NETWORK *
- 10. ANALOG SIGNAL CONTINUOUS WAVEFORM PASSES THRU SYSTEM VOICE COMMUNICATIONS *
- 11. DIGITAL SIGNAL DISCRETE WAVEFORM TWO DISCRETE STATES: 1-BIT & 0-BIT ON / OFF PULSE DATA COMMUNICATION USES MODEM TO TRANSLATE ANALOG TO DIGITAL, DIGITAL TO ANALOG * 0010111010011101001010101110111100100010000101111010110100111010010010110010101101100
- 12. COMMUNICATION CHANNELS MEANS BY WHICH DATA ARE TRANSMITTED: TWISTED WIRES: Copper Wires COAXIAL CABLE: Insulated Copper Wires FIBER-OPTIC CABLE MICROWAVE *
- 13. SUPER CLEAR GLASS STRANDS FAST, LIGHT, DURABLE TRILLIONS OF BITS PER SECOND, FULL DUPLEX EXPENSIVE, HARDER TO INSTALL OFTEN USED AS BACKBONE OF NETWORKS * FIBER OPTICS SIGNAL LASER CABLE PHOTO DETECTOR SIGNAL
- 14. BACKBONE: Fiber optics cable carries light signals to distribution nodes, which use copper wires to user DENSE WAVE DIVISION MULTIPLEXING (DWDM): Next-generation, uses many colors, (up to 160) each a channel, increases capacity of a fiber to 6.4 terabits per second * FIBER OPTICS
- 15. WIRELESS TRANSMISSION TECHNOLOGIES PAGERS: Small pager beeps when receives short message CELLULAR TELEPHONE: Device uses radio waves to reach antennas within areas called cells MOBILE DATA NETWORKS: Radio - based data network using hand-held computers, cheap, efficient *
- 16. WIRELESS TRANSMISSION TECHNOLOGIES PERSONAL COMMUNICATION SERVICE: Cellular; lower power; higher frequency. Smaller phones not shielded by buildings, tunnels PERSONAL DIGITAL ASSISTANT: Pen sized, hand-held, digital communicator SMART PHONE: Wireless, voice, text, Internet *
- 17. ORBITING SATELLITES UPLINK MICROWAVE TRANSMISSION DOWNLINK
- 18. TRANSMISSION SPEED: Bits per Second (BPS) or Baud BANDWIDTH: Capacity of Channel; Difference between Highest & Lowest Frequencies * COMMUNICATIONS CHANNELS
- 19. SPEEDS & COST OF MEDIA MEDIUM SPEED COST TWISTED WIRE 300 BPS - 10 MBPS LOW MICROWAVE 256 KBPS - 100 MBPS SATELLITE 256 KBPS - 100 MBPS COAXIAL CABLE 56 KBPS - 200 MBPS FIBER OPTICS 500 KBPS - 6.4 TBPS HIGH BPS: BITS PER SECOND KBPS: KILOBITS PS, MBPS: MEGABITS PS, GBPS: GIGABITS PS, TBPS: TERABITS PS
- 20. COMMUNICATIONS PROCESSORS FRONT- END PROCESSOR: Minicomputer manages communication for host computer CONCENTRATOR: Computer collects messages for batch transmission to host computer CONTROLLER: Computer controls interface between CPU and peripheral devices MULTIPLEXER: Allows channel to carry multiple sources simultaneously *
- 21. NETWORK TOPOLOGIES STAR HOST USER USER USER USER
- 22. NETWORK TOPOLOGIES BUS USER USER USER USER USER USER
- 23. NETWORK TOPOLOGIES RING USER USER USER USER
- 24. LOCAL NETWORKS PRIVATE BRANCH EXCHANGE (PBX): firm’s central switching system LOCAL AREA NETWORK (LAN): dedicated channels; limited distance (less than 2000 foot radius); higher capacity than PBX. Can share expensive hardware & software *
- 25. LOCAL AREA NETWORK (LAN) GATEWAY: Connection to other networks ROUTER: Forwards data to other networks NETWORK OPERATING SYSTEM (NOS): Manages file server; routes communications on network PEER - TO - PEER: In some small networks all computers have equal power *
- 26. Network spans large geographic distances. Can include cable, satellite, microwave SWITCHED LINES: Route determined by current traffic DEDICATED LINES: Constantly available for high-volume traffic * WIDE - AREA NETWORK (WAN)
- 27. VALUE-ADDED NETWORK (VAN) PRIVATE, MULTIPATH, DATA ONLY 3rd PARTY MANAGED USED BY SEVERAL ORGANIZATIONS SUBSCRIPTION BASIS *
- 28. NETWORK SERVICES PACKET SWITCHING FRAME RELAY ASYNCHRONOUS TRANSFER MODE (ATM) INTEGRATED SERVICES DIGITAL NETWORK (ISDN) SYMMETRIC DIGITAL SUBSCRIBER LINE CABLE MODEM T1 LINE *
- 29. PACKET SWITCHING (X.25) FORM OF V alue A dded N etwork BREAKS DATA BLOCKS INTO SMALL PACKETS (e.g.: 128 Bytes) PACKETS ROUTED BY MOST ECONOMICAL MEANS REASSEMBLED AT DESTINATION *
- 30. FRAME RELAY PACKAGES DATA INTO BLOCKS (FRAMES) HIGH-SPEED TRANSMISSION RELIABLE LINES NO ERROR-CORRECTION ROUTINES *
- 31. ASYNCHRONOUS TRANSFER MODE (ATM) CELL: 53 Groups of 8 Bytes Each USES FIBER OPTICS CABLE INDEPENDENT OF VENDOR HARDWARE SPEEDS CAN TIE LAN TO WAN *
- 32. INTEGRATED SERVICES DIGITAL NETWORK (ISDN) INTERNATIONAL STANDARD FOR TRANSMITTING VOICE, VIDEO, DATA OVER PUBLIC TELEPHONE LINES *
- 33. OTHER SERVICES: DIGITAL SUBSCRIBER LINE (DSL): enhancing capacity over copper telephone lines CABLE MODEM: modem for cable TV for high-speed access to Internet T1 LINE: dedicated telephone connection, 24 channels @ 1.544 megabits per second *
- 34. OTHER SERVICES: BROADBAND: High-speed transmission, multiple channels NETWORK CONVERGENCE: Enables simultaneous transmission of voice, data, video. Attractive for multimedia applications: Video collaboration, voice-data call centers, distance learning, unified messaging *
- 35. E-COMMERCE & E-BUSINESS TECHNOLOGIES ELECTRONIC MAIL (e-mail) GROUPWARE VOICE MAIL FACSIMILE MACHINES (fax) TELECONFERENCING DATACONFERENCING VIDEOCONFERENCING *
- 36. E-COMMERCE & E-BUSINESS TECHNOLOGIES DIGITAL INFORMATION SERVICES: Commercial service provides desired mix DISTANCE LEARNING: Education, training delivered over a distance, can include printed material, teleconferencing, interactive multimedia, Web sites *
- 37. COMMERCIAL DIGITAL INFORMATION SERVICES
- 38. ELECTRONIC DATA INTERCHANGE (EDI) COMPUTER - TO - COMPUTER EXCHANGE BETWEEN TWO ORGANIZATIONS OF STANDARD BUSINESS TRANSACTION DOCUMENTS * COMPUTER COMPUTER SELLER CUSTOMER ORDERS, PAYMENTS SHIPPING NOTICES, PRICE UPDATES, INVOICES
- 39. 8 TELECOMMUNICATIONS AND NETWORKS c h a p t e r