1. COMMUNICATIONS AND NETWORKS

2. -2 Competencies Discuss connectivity, the wireless revolution, and communication systems Describe physical and wireless communications channels Discuss connection devices Describe data transmission factors

3. -3 Competencies cont. Discuss networks and key network terminology Describe the different types of networks Describe network architectures Describe organizational uses of Internet technologies

4. -4 What is Communication? The process of sharing data, programs, and information between two or more computers

5. -5 Communications Today

6. -6 Communication Systems

7. -7 Communication Channels Channels carry data from one computer to another Two categories of communication channels Physical connection Wireless connection

8. -8 Physical Connections Telephone lines Coaxial cable Fiber-optic cable

9. -9 Wireless Connections Infrared Broadcast radio Microwave Stations Bluetooth Satellite Uplink/Downlink Global Positioning System

10. -10 More on Satellites Global positioning Network of 24 satellites Owned by the Defense Department Global positioning system (GPS) Devices used to determine location Provides navigational support

11. -11 Connection Devices Types of signals Analog Digital Types of modems Internal External PC Card Wireless

12. -12 Types of Connections Digital subscriber line (DSL) Uses existing phone lines ADSL (Asymmetric digital subscriber line) Cable modems Uses existing TV cable Provides speeds as fast as DSL at a lower cost Satellite/air connection services Seven times faster than dial-up Slower than DSL & cable modem

13. -13 User Connection Costs & Speeds TypeFeeSpeedSeconds to Get Images Dial-up$1656 kbps45.0 DSL 501.5 mbps1.7 Cable Modem 401.5 mbps1.7 Satellite 70900 kbps2.8

14. -14 Bandwidth Measurement of the capacity of the channel Categories Low bandwidths or Voiceband Medium band Broadband Used for high capacity transmission Used by DSL, cable & satellite

15. -15 Protocols Set of communication rules Standard for Internet: TCP/IP Transmission control protocol/Internet protocol Identifies devices Reformats information

16. -16 Networks A computer network is a communication system Connects two or more computers Allows information exchange

17. -17 Network Terms Node Client Server Hub Network interface cards (NIC) Network operating system (NOS) Distributed processing Host computer Network manager

18. -18 Network Types Local area networks Home networks Metropolitan area networks Wide area networks

19. -19 Network Architecture Architecture describes how a network is arranged Arrangement is called topology Types of network topology Star Bus Ring Hierarchical

20. -20 Star Network Smaller computers linked to a central unit Central unit is called the network hub Control is maintained by polling

21. -21 Bus Network Each device handles its own communication control There is no host computer Has a common connecting cable called a backbone

22. -22 Ring Network Each device is connected to two other devices No central file server or computer Useful in a decentralized environment

23. -23 Hierarchical Network Several computers linked to a central host Computers are hosts to other computers Useful in centralized organizations

24. -24 Strategies Strategy is a way of coordinating the sharing of information and resources Common network strategies Terminal Client/server Peer-to-peer Peer-to-Peer Network System

25. -25 Organizational Internets

26. -26 Internets and Extranets Intranets Private network within an organization Provides information to employees Extranets Private network that connects organizations Used to allow suppliers and others access Firewalls Security system Protects against external threats

27. -27 A Look to the Future Wireless Robotic Car Pod car (Personalization on Demand) Predicts and responds Designed to learn and adapt to an individual's driving needs and habits

28. -28 FAQs What is fiber-optic cable? My Palm Pilot uses Bluetooth. What is it? What is a modem? What is DSL? How does it work? How fast is broadband bandwidth? What is a local area network? What is meant by peer-to-peer?

29. -29 Discussion Questions Discuss what is meant by the wireless revolution. Discuss the four types of service connections. Discuss the advantages and disadvantages of the four network topologies. Explain the connections in a home network. Describe the different network topologies. Describe a GPS system.