CH09-Networks and Communications
5 likes•755 views
This chapter discusses computer networks and communications. It defines networks as collections of connected computers and devices that allow sharing of resources and data. The chapter describes different types of networks including LANs, MANs, and WANs. It also explains common network devices, transmission media, and wireless communication standards used to connect computers and transmit data. The chapter provides an overview of how computer communications work and examples of applications like email, instant messaging, and file transfers that rely on computer networks.
CH09-Networks and Communications
- 1. Chapter 9 Networks and Communications Discovering Computers 2012 Your Interactive Guide to the Digital World
- 2. Objectives Overview Discuss the purpose of the List advantages of using a components required for Describe the uses of network, and differentiate successful communications computer communications among LANs, MANs, and and identify various sending WANs and receiving devices Differentiate between client/server and peer-to- Differentiate among a star Describe the various peer networks, and network, bus network, and network communications describe how a P2P ring network standards network works See Page 459 Discovering Computers 2012: Chapter 9 2 for Detailed Objectives
- 3. Objectives Overview Describe various types Explain the purpose of Describe commonly of lines for communications used communications communications over software devices the telephone network Discuss different ways Describe various to set up a home physical and wireless network transmission media See Page 459 Discovering Computers 2012: Chapter 9 3 for Detailed Objectives
- 4. Communications • Computer communications describes a process in which two or more computers or devices transfer data, instructions, and information Communications Sending device Receiving device channel Page 460 Discovering Computers 2012: Chapter 9 4
- 5. Communications Pages 460 – 461 Discovering Computers 2012: Chapter 9 5 Figure 9-1
- 6. Uses of Computer Communications Blogs Chat rooms E-mail Fax Instant FTP Internet Newsgroups messaging Video RSS VoIP Web conferencing Web 2.0 Web folders Wikis Page 462 Discovering Computers 2012: Chapter 9 6
- 7. Uses of Computer Communications • Users can send and receive wireless messages using wireless messaging services Pages 462 – 463 Discovering Computers 2012: Chapter 9 7 Figure 9-3
- 8. Uses of Computer Communications Text messaging (SMS) allows users to send and receive short text messages on a phone or other mobile device or computer Picture messaging allows users to send pictures and sound files Video messaging allows users to send short video clips Wireless instant messaging allows wireless users to exchange real-time messages with one or more other users Pages 463 - 464 Discovering Computers 2012: Chapter 9 8
- 9. Uses of Computer Communications • Wireless Internet access points allow people to connect wirelessly to the Internet from home, work, school, and in many public locations Pages 464 – 465 Discovering Computers 2012: Chapter 9 9 Figure 9-4
- 10. Uses of Computer Communications • A cybercafé is a coffeehouse, restaurant, or other location that provides personal computers with Internet access to its customers Page 466 Discovering Computers 2012: Chapter 9 10 Figure 9-5
- 11. Uses of Computer Communications • A global positioning system (GPS) is a navigation system that consists of one or more earth-based receivers that accept and analyze signals sent by satellites in order to determine the GPS receiver’s geographic location • GPS receivers are: Built into Available as a Available with many mobile handheld new vehicles devices device Page 466 Discovering Computers 2012: Chapter 9 11
- 12. Uses of Computer Communications Page 467 Discovering Computers 2012: Chapter 9 12 Figure 9-6
- 13. Uses of Computer Communications Groupware Voice mail • Helps groups of people work • Allows someone to leave a together on projects and voice message for one or share information over a more people network • Computer in voice mail • Component of workgroup system converts an analog computing voice message into digital • Major feature is group form scheduling • A voice mailbox is a storage location on a hard disk in the voice mail system Page 467 Discovering Computers 2012: Chapter 9 13
- 14. Uses of Computer Communications • Many programs provide a means to collaborate, or work online, with other users connected to a server • Collaboration software includes tools that enable users to share documents via online meetings and communicate with other connected users Document Online Web management meetings conferences systems Page 468 Discovering Computers 2012: Chapter 9 14
- 15. Uses of Computer Communications Page 468 Discovering Computers 2012: Chapter 9 15 Figure 9-7
- 16. Uses of Computer Communications • Web services enable programmers to create applications that communicate with other remote computers over the Internet or on an internal business network • A mashup is a Web application that combines services from two or more sources Page 469 16 Figure 9-8 Discovering Computers 2012: Chapter 9
- 17. Networks • A network is a collection of computers and devices connected together via communications devices and transmission media • Advantages of a network include: Facilitating Sharing Sharing data communications hardware and information Sharing Transferring software funds Pages 470 - 471 Discovering Computers 2012: Chapter 9 17
- 18. Networks Page 470 Discovering Computers 2012: Chapter 9 18 Figure 9-9
- 19. Networks • A local area network (LAN) is a network that connects computers and devices in a limited geographical area • A wireless LAN (WLAN) is a LAN that uses no physical wires Page 472 19 Figures 9-10 – 9-11 Discovering Computers 2012: Chapter 9
- 20. Networks • A metropolitan area network (MAN) connects LANs in a metropolitan area • A wide area network (WAN) is a network that covers a large geographical area Page 473 Discovering Computers 2012: Chapter 9 20 Figure 9-12
- 21. Networks • The design of computers, devices, and media on a network is sometimes called the network architecture Client/server network Peer-to-peer network Pages 473 – 474 Discovering Computers 2012: Chapter 9 21 Figures 9-13 – 9-14
- 22. Networks • P2P describes an Internet network on which users access each other’s hard disks and exchange files directly over the Internet Page 475 Discovering Computers 2012: Chapter 9 22 Figure 9-15
- 23. Networks • A network topology refers to the layout of the computers and devices in a communications network Star network Bus network Ring network Pages 475 – 477 Discovering Computers 2012: Chapter 9 23 Figures 9-16 – 9-18
- 24. Networks An intranet is an An extranet allows internal network customers or that uses Internet suppliers to access technologies part of its intranet Page 477 Discovering Computers 2012: Chapter 9 24
- 25. Network Communications Standards Token Ethernet TCP/IP Wi-Fi ring Bluetooth UWB IrDA RFID WiMAX WAP Page 477 Discovering Computers 2012: Chapter 9 25
- 26. Network Communications Standards Ethernet is a network standard that specifies no computer controls when data can be transmitted The token ring standard specifies that computers and devices on the network share or pass a special signal (token) TCP/IP is a network standard that defines how messages are routed from one end of a network to another Page 478 Discovering Computers 2012: Chapter 9 26
- 27. Network Communications Standards Page 479 Discovering Computers 2012: Chapter 9 27 Figure 9-19
- 28. Network Communications Standards • Wi-Fi identifies any network based on the 802.11 standard that facilitates wireless communication • Sometimes referred to as wireless Ethernet Page 479 28 Discovering Computers 2012: Chapter 9 Figure 9-20
- 29. Network Communications Standards • Bluetooth defines how two Bluetooth devices use short- range radio waves to transmit data • UWB (ultra-wideband) specifies how two UWB devices use short-range radio waves to communicate at high speeds • IrDA transmits data wirelessly via infrared (IR) light waves • RFID uses radio signals to communicate with a tag placed in or attached to an object, animal, or person Pages 480 - 481 Discovering Computers 2012: Chapter 9 29
- 30. Network Communications Standards Page 481 Discovering Computers 2012: Chapter 9 30 Figure 9-21
- 31. Network Communications Standards Wireless Application WiMAX (802.16) Protocol (WAP) • Developed by IEEE • Specifies how some mobile • Towers can cover a 30-mile devices can display the radius content of Internet services • Two types are fixed • Web wireless and mobile • E-mail wireless • Chat rooms • Provides wireless • Uses a client/server broadband Internet access network Page 482 Discovering Computers 2012: Chapter 9 31
- 32. Communications Software • Communications software consists of programs that: Help users establish Manage the a connection to transmission of another computer data, instructions, or network and information Provide an interface for users to communicate with one another Page 482 Discovering Computers 2012: Chapter 9 32
- 33. Communications Over the Telephone Network • The public switched telephone network (PSTN) is the worldwide telephone system Pages 482 – 483 Discovering Computers 2012: Chapter 9 33 Figure 9-23
- 34. Communications Over the Telephone Network Dial-up Dedicated ISDN line lines line T-carrier DSL FTTP line ATM Pages 483 - 485 Discovering Computers 2012: Chapter 9 34
- 35. Communications Over the Telephone Network Page 483 Discovering Computers 2012: Chapter 9 35 Figure 9-24
- 36. Communications Over the Telephone Network • ADSL connections transmit data downstream at a much faster rate than upstream Page 484 Discovering Computers 2012: Chapter 9 36 Figure 9-25
- 37. Communications Devices • A communications device is any type of hardware capable of transmitting data, instructions, and information between a sending device and a receiving device • A dial-up modem converts signals between analog and digital Page 485 Discovering Computers 2012: Chapter 9 37
- 38. Communications Devices • A digital modem sends and receives data and information to and from a digital line DSL Cable modem modem Page 486 Discovering Computers 2012: Chapter 9 38
- 39. Communications Devices Page 486 39 Discovering Computers 2012: Chapter 9 Figures 9-26 – 9-27
- 40. Communications Devices • A wireless modem uses the cell phone network to connect to the Internet wirelessly from a notebook computer, a smart phone, or other mobile device Page 487 Discovering Computers 2012: Chapter 9 40 Figure 9-28
- 41. Communications Devices • A network card enables a computer or device to access a network • Available in a variety of styles • Wireless network cards often have an antenna Page 487 41 Discovering Computers 2012: Chapter 9 Figure 9-29
- 42. Communications Devices • A wireless access point is a central communications device that allows computers and devices to transfer data wirelessly among themselves or to a wired network Page 487 Discovering Computers 2012: Chapter 9 42 Figure 9-30
- 43. Communications Devices • A router connects multiple computers or other routers together and transmits data to its correct destination on a network • Many are protected by a hardware firewall Page 488 43 Discovering Computers 2012: Chapter 9 Figure 9-31
- 44. Communications Devices • A hub or switch connects several devices in a network together Pages 488 – 489 Discovering Computers 2012: Chapter 9 44 Figure 9-32
- 45. Home Networks • Home networks provide computers with the following capabilities: Connect to the Share a single high- Access files and Internet at the speed Internet programs on other Share peripherals same time connection computers Connect game Play multiplayer Subscribe to and consoles to the games use VoIP Internet Page 489 Discovering Computers 2012: Chapter 9 45
- 46. Home Networks • Types of wired home networks: Ethernet Powerline cable Phoneline Page 489 Discovering Computers 2012: Chapter 9 46
- 47. Home Networks Page 490 Discovering Computers 2012: Chapter 9 47 Figure 9-33
- 48. Communications Channel • The amount of data that can travel over a communications channel sometimes is called the bandwidth • Latency is the time it takes a signal to travel from one location to another on a network • Transmission media carries one or more signals • Broadband media transmit multiple signals simultaneously Page 491 48 Discovering Computers 2012: Chapter 9 Figure 9-34
- 49. Physical Transmission Media Page 492 Discovering Computers 2012: Chapter 9 49 Figure 9-35
- 50. Physical Transmission Media Twisted-pair cable Fiber-optic cable Coaxial cable Page 493 Discovering Computers 2012: Chapter 9 50 Figures 9-36 – 9-38
- 51. Wireless Transmission Media Page 494 Discovering Computers 2012: Chapter 9 51 Figure 9-39
- 52. Wireless Transmission Media • Cellular radio is a form of broadcast radio that is used widely for mobile communications Pages 494 - 495 Discovering Computers 2012: Chapter 9 52 Figure 9-40
- 53. Wireless Transmission Media • Microwaves are radio waves that provide a high- speed signal transmission Page 496 Discovering Computers 2012: Chapter 9 53 Figure 9-41
- 54. Wireless Transmission Media • A communications satellite is a space station that receives microwave signals from an earth-based station, amplifies it, and broadcasts the signal over a wide area Page 496 54 Discovering Computers 2012: Chapter 9 Figure 9-42
- 55. Video: Got Your Video Right Here CLICK TO START Discovering Computers 2012: Chapter 9 55
- 56. Summary Overview of How to join communications computers into a terminology and network applications Various communications devices, media, and procedures Page 497 Discovering Computers 2012: Chapter 9 56
- 57. Chapter 9 Networks and Communications Discovering Computers 2012 Your Interactive Guide to the Digital World Chapter 9 Complete