TELECOMMUNICATIONS AND NETWORKS

1. 8 TELECOMMUNICATIONS AND NETWORKS

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 • Routers, Hubs and Switches *

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 • Radio Frequency *

13. SIGNAL LASER CABLE PHOTO DETECTOR SIGNAL FIBER OPTICS • SUPER CLEAR GLASS STRANDS • FAST, LIGHT, DURABLE • TRILLIONS OF BITS PER SECOND, FULL DUPLEX • EXPENSIVE, HARDER TO INSTALL • OFTEN USED AS BACKBONE OF NETWORKS *

14. FIBER OPTICS • 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 *

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 MICROWAVE TRANSMISSION UPLINK DOWNLINK

18. COMMUNICATIONS CHANNELS • TRANSMISSION SPEED:Bits per Second (BPS) or Baud • BANDWIDTH:Capacity of Channel; Difference between Highest & Lowest Frequencies *

19. 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 SPEEDS & COST OF MEDIA

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. USER USER HOST USER USER NETWORK TOPOLOGIES STAR Host mainframe computers use this with terminals.

22. USER USER USER USER USER USER NETWORK TOPOLOGIES Network devices may look like a star configuration BUS Collision detection is required for multiple devices to share the same bus. This creates some inefficiency.

23. Device Device Device Device NETWORK TOPOLOGIES RING A token is passed from device to device. Synchronizing access to the ring. Single rings exists in older systems. Newer double rings are more reliable.

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. WIDE - AREA NETWORK (WAN) 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 *

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 Value Added Network • 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. SELLER CUSTOMER ORDERS, PAYMENTS COMPUTER COMPUTER SHIPPING NOTICES, PRICE UPDATES, INVOICES ELECTRONIC DATA INTERCHANGE (EDI) COMPUTER - TO - COMPUTER EXCHANGE BETWEEN TWO ORGANIZATIONS OF STANDARD BUSINESS TRANSACTION DOCUMENTS *

39. 8 TELECOMMUNICATIONS AND NETWORKS