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Communications and Networks

This chapter covers the essential aspects of communication and networks, highlighting their significance in today's interconnected world. It discusses various forms of connectivity, including wireless communications and messaging. Key elements like communication channels, connection devices, and data transmission factors are outlined. Different network types and architectures are described, offering insight into how resources and individuals are linked. The text emphasizes the wireless revolution and the role of modern technologies in enhancing communication and connectivity across various platforms.

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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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