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Communications and Networks

Chapter 8 . Communications and Networks. Overview. Discuss Connectivity Discuss The Wireless Revolution Describe Communication Channels Discuss Connection Devices Discuss Connection Services Describe Data Transmission Factors Describe Different Types Of Networks

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Communications and Networks

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  1. Chapter 8 Communications and Networks

  2. Overview • Discuss Connectivity • Discuss The Wireless Revolution • Describe Communication Channels • Discuss Connection Devices • Discuss Connection Services • Describe Data Transmission Factors • Describe Different Types Of Networks • Describe Network Architectures

  3. Communications • Connectivity • Use Networks to Link People and Resources • The Wireless Revolution • Stay Connected with Anyone Anywhere Any Time

  4. Uses • Wireless Messaging • Text Messaging • Send / Receive Text Messages Using Phone • 14-17: 60 v. 5 • Picture Messaging • Send / Receive Graphics, Pictures, Video • Sexting: 30% of 17-year-olds • Web Services Pew Internet 5/10 Pew Internet 12/09

  5. Uses • GPS (Global Positioning System) • Signals Sent by Satellites Orbiting Earth • Signal Sent Every 1/1000 of a Second • Earth-based Receivers Analyze Signals • Determine Receiver’s Geographic Location • Groupware • Assists Groups in Working Together • Share Data Over Network • e.g., Schedule Meetings

  6. Uses • Web Services • Software Applications • Communicate with Other Remote Computers • Use Internet or Internal Business Network • Mashup • Combines Services from Multiple Sources

  7. Communication Systems • Basic Elements • Sending and Receiving Devices • Communication Channel • Connection Devices • Data Transmission Specifications

  8. Communication Channels • Physical Connections • Twisted-pair Cable • Telephone Lines • Ethernet Cables • Used in Networks to Connect Variety of Components • Coaxial Cable • Over 80x Capacity of Twisted-pair • Fiber-optic Cable • Over 26,000x Capacity of Twisted-pair

  9. Communication Channels • Wireless Connections • Bluetooth • Short-range Radio Signals (33 Feet) • Wi-Fi (Wireless Fidelity) • High-frequency Radio Signals • Microwave • Line-of-sight

  10. Communication Channels • Wireless Connections • WiMax • Extends Range of Wi-fi Networks Using Microwaves • LTE (Long Term Evolution) • Currently Similar to WiMax with Future Speed Benefits • Satellite • Microwave Relay Stations in Space • Uplink / Downlink • Affected by Weather

  11. Connection Devices • Modem • Modulation – Digital to Analog • Demodulation – Analog to Digital • Transfer Rate • Bps – Bits per Second • Typically Mbps

  12. Connection Devices • Modem • Types • Telephone • Connect Computer Directly to Telephone Line • DSL • Uses Standard Phone Lines • Creates High-speed Connection to Phone Company's Offices • Cable • Uses Same Coaxial Cable as Your Television • Wireless • Portable High-speed Connectivity From Virtually Anywhere

  13. Connection Services • DSL (Digital Subscriber Line) • Use Existing Phone Lines • Cable • Uses Existing TV Cable • Satellite Connection Services • Use Almost Anywhere • Slower than DSL and Cable Modem • Cellular Services • 4G Using WiMax and LTE

  14. Data Transmission • Bandwidth • Measurement of Capacity of Channel • Categories • Voiceband • Medium Band • Broadband • DSL, Cable, and Satellite • Baseband

  15. Data Transmission • Protocol • Collection of Procedures • Establish, Maintain, & Terminate Transmissions • Type of Error Checking Used • Data Compression Method, If Any • Indicate Finished Sending Message • Indicate Message Has Been Received

  16. Data Transmission • Protocol • TCP/IP • Internet Standard • Identification • IP Addressing • Domain Name Server (DNS) • Packetization

  17. Networks • Node • Any Device Connected to Network • Client • Node that Requests and Uses Resources • Server • Node that Shares Resources with Other Nodes • Directory Server • Manages Resources for Entire Network

  18. Networks • Host • Any Computer System Accessed Over a Network • Router • Forwards Data Packets to Their Destination • Switch • Coordinates Flow of Data • NIC • NOS

  19. Network Types • Local Area Network (LAN) • Home Network • Wireless LAN (WLAN) • Hotspots • Personal Area Network (PAN) • Metropolitan Area Network (MAN) • Wide Area Network (WAN)

  20. Network Architecture • Topologies • Describes How a Network is Arranged • Bus • Ring • Star • Tree • Mesh

  21. Network Architecture • Strategies • How Resources are Coordinated and Shared • Client/Server • Server Provides Access to Resources for Clients • P2P (Peer-to-peer) • Can Act as Both Client and Server • File Sharing

  22. Organizational Networks • Internet Technologies • Intranet • Private Network Within An Organization • Extranet • Private Network • Provides Limited Access To Network • Vendors • Customers

  23. Organizational Networks • Network Security • Firewall • Proxy Server • Controls Access to Network • Intrusion Detection System (IDS) • Analyzes Incoming and Outgoing Traffic • Virtual Private Network (VPN) • Secure Connection to Company Network • For Mobile Users, Vendors, & Customers

  24. Careers in IT • Network Administrator • Manage Company LAN and WAN Networks • Network Design, Implementation, Maintenance • Plan and Implement Network Security • Bachelor's Degree in Computer Science • Good Communication Skills • Annual Salary of $46,000 - $84,000

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