Communications and Networks
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This document discusses computer networks and communications. It begins by describing the basic components of a communications system, including sending and receiving devices connected by a communications channel. It then discusses the various uses of computer communications, such as email, instant messaging, wireless messaging, and Internet access. The document outlines different types of networks including LANs, WANs, and wireless networks. It also describes common network topologies and standards used for networking, such as Ethernet, TCP/IP, Wi-Fi, Bluetooth, and RFID.
Communications and Networks
- 1. Discovering Computers 2011 Living in a Digital World
- 2. Objectives Overview Objectives Overview Discuss the purpose of the List advantages of using a 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 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 describe how a P2P ring network ring network standards network works See Page 459 Discovering Computers 2011: Living in a Digital World 2 for Detailed Objectives Chapter 9
- 3. Objectives Overview Objectives Overview Describe various types Describe various types Explain the purpose of E l i h f Describe commonly D ib l of lines for communications used communications communications over software devices the telephone network the telephone network Discuss different ways Describe various to set up a home physical and wireless network transmission media transmission media See Page 459 Discovering Computers 2011: Living in a Digital World 3 for Detailed Objectives Chapter 9
- 4. Communications • Computer communications describes a process in p which two or more computers or devices transfer data, instructions, and information Communications Sending device Receiving device channel Page 460 Discovering Computers 2011: Living in a Digital World 4 Chapter 9
- 5. Communications Pages 460 – 461 Discovering Computers 2011: Living in a Digital World 5 Figure 9‐1 Chapter 9
- 6. Uses of Computer Communications Uses of Computer Communications Blogs Chat rooms E‐mail Fax Instant FTP Internet Newsgroups g p messaging Vid Video RSS VoIP Web conferencing Click to view Web Link, click Chapter 9, Click Web Web 2.0 Web folders Wikis Link from left navigation navigation, then click Wikis below Chapter 9 Page 462 Discovering Computers 2011: Living in a Digital World 6 Chapter 9
- 7. Uses of Computer Communications Uses of Computer Communications • Users can send and receive wireless messages g g g using wireless messaging services Pages 462 – 463 Discovering Computers 2011: Living in a Digital World 7 Figure 9‐3 Chapter 9
- 8. Uses of Computer Communications Uses of Computer Communications Text messaging 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 messages with one or more other users Click to view Web Link, click Chapter 9, Click Web Link from left navigation navigation, then click Video Messaging below Chapter 9 Pages 463 ‐ 464 Discovering Computers 2011: Living in a Digital World 8 Chapter 9
- 9. Uses of Computer Communications 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 2011: Living in a Digital World 9 Figure 9‐4 Chapter 9
- 10. Uses of Computer Communications Uses of Computer Communications • A cybercafé is a coffeehouse, restaurant, or other p p p location that provides personal computers with Internet access to its customers Page 466 Discovering Computers 2011: Living in a Digital World 10 Figure 9‐5 Chapter 9
- 11. Uses of Computer Communications 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 Built into Available as a Available as a Available with many mobile handheld new vehicles devices device Click to view Web Link, click Chapter 9, Click Web navigation, Link from left navigation then click GPS below Chapter 9 Page 466 Discovering Computers 2011: Living in a Digital World 11 Chapter 9
- 12. Uses of Computer Communications Uses of Computer Communications Page 467 Discovering Computers 2011: Living in a Digital World 12 Figure 9‐6 Chapter 9
- 13. Uses of Computer Communications Uses of Computer Communications Groupware Voice mail •H l Helps groups of people work f l k • All Allows someone to leave a t l together on projects and voice message for one or share information over a p p more people network • Computer in voice mail • Component of workgroup system converts an analog computing ti voice message into digital i i t di it l • Major feature is group form scheduling • A voice mailbox is a storage A voice mailbox is a storage location on a hard disk in the voice mail system Page 467 Discovering Computers 2011: Living in a Digital World 13 Chapter 9
- 14. Uses of Computer Communications Uses of Computer Communications • Collaboration software includes tools that enable g users to share documents via online meetings and communicate with other connected users Online Web meetings conferences Document Document Click to view Web Link, management click Chapter 9, Click Web Link from left navigation navigation, then click Microsoft Groove systems below Chapter 9 Page 468 Discovering Computers 2011: Living in a Digital World 14 Chapter 9
- 15. Uses of Computer Communications Uses of Computer Communications Page 468 Discovering Computers 2011: Living in a Digital World 15 Figure 9‐7 Chapter 9
- 16. Uses of Computer Communications Uses of Computer Communications • W b Web services enable i bl programmers to create applications that applications that communicate with other remote computers over the Internet or on an internal business network • A A mashup i W b h is a Web application that combines services from two or services from two or more sources Page 469 Discovering Computers 2011: Living in a Digital World 16 Figure 9‐8 Chapter 9
- 17. Networks • A network is a collection of computers and g devices connected together via communications devices and transmission media • Advantages of a network include: Advantages of a network include: Facilitating g Sharing g Sharing data g communications hardware and information Sharing Transferring software funds Pages 470 ‐ 471 Discovering Computers 2011: Living in a Digital World 17 Chapter 9
- 18. Networks Page 470 Discovering Computers 2011: Living in a Digital World 18 Figure 9‐9 Chapter 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 Discovering Computers 2011: Living in a Digital World 19 Figures 9‐10 – 9‐11 Chapter 9
- 20. Networks • A metropolitan area network (MAN) connects p LANs in a metropolitan area • A wide area network (WAN) is a network that covers a is a network that covers a large geographical area Page 473 Discovering Computers 2011: Living in a Digital World 20 Figure 9‐12 Chapter 9
- 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 2011: Living in a Digital World 21 Figures 9‐13 – 9‐14 Chapter 9
- 22. Networks • P2P describes an Internet network on which users g access each other’s hard disks and exchange files directly over the Internet Click to view Web Link, click Chapter 9, Click Web Link from left navigation navigation, then click P2P below Chapter 9 Page 475 Discovering Computers 2011: Living in a Digital World 22 Figure 9‐15 Chapter 9
- 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 2011: Living in a Digital World 23 Figures 9‐16 – 9‐18 Chapter 9
- 24. Networks An intranet is an An extranet allows internal network customers or that uses Internet suppliers to access pp technologies part of its intranet Page 477 Discovering Computers 2011: Living in a Digital World 24 Chapter 9
- 25. Network Communications Standards Network Communications Standards Token Ethernet TCP/IP Wi Fi Wi‐Fi i ring Bluetooth UWB IrDA RFID WiMAX WAP Page 477 Discovering Computers 2011: Living in a Digital World 25 Chapter 9
- 26. Network Communications Standards Network Communications Standards Ethernet is a network standard that specifies no computer controls when data can be transmitted controls when data can be transmitted The token ring standard specifies that computers and 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 Click to view Web Link, click Chapter 9, Click Web Link from left navigation navigation, then click Ethernet below Chapter 9 Page 478 Discovering Computers 2011: Living in a Digital World 26 Chapter 9
- 27. Network Communications Standards Network Communications Standards Page 479 Discovering Computers 2011: Living in a Digital World 27 Figure 9‐19 Chapter 9
- 28. Network Communications Standards 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 Discovering Computers 2011: Living in a Digital World 28 Figure 9‐20 Chapter 9
- 29. Network Communications Standards 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 Click to view Web Link, click Chapter 9, Click Web Link from left navigation navigation, then click RFID below Chapter 9 Pages 480 ‐ 481 Discovering Computers 2011: Living in a Digital World 29 Chapter 9
- 30. Network Communications Standards Network Communications Standards Page 481 Discovering Computers 2011: Living in a Digital World 30 Figure 9‐21 Chapter 9
- 31. Network Communications Standards Network Communications Standards Wireless Application WiMAX (802.16) Protocol (WAP) • Developed by IEEE • Specifies how some mobile • Towers can cover a 30‐mile Towers can cover a 30‐mile devices can display the devices can display the radius content of Internet services yp • 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 2011: Living in a Digital World 31 Chapter 9
- 32. Communications Software 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 interface for users to communicate with one another Page 482 Discovering Computers 2011: Living in a Digital World 32 Chapter 9
- 33. Communications Over the Telephone Network h l h k • The public switched telephone network (PSTN) is p y the worldwide telephone system Pages 482 – 483 Discovering Computers 2011: Living in a Digital World 33 Figure 9‐23 Chapter 9
- 34. Communications Over the Telephone Network h l h k Dial‐up Dedicated ISDN line lines line T‐carrier DSL FTTP line Click to view Web Link, click Chapter 9, Click Web ATM Link from left navigation navigation, then click DSL below Chapter 9 Pages 483 ‐ 485 Discovering Computers 2011: Living in a Digital World 34 Chapter 9
- 35. Communications Over the Telephone Network h l h k Page 483 Discovering Computers 2011: Living in a Digital World 35 Figure 9‐24 Chapter 9
- 36. Communications Over the Telephone Network h l h k • ADSL connections transmit data downstream at a p much faster rate than upstream Page 484 Discovering Computers 2011: Living in a Digital World 36 Figure 9‐25 Chapter 9
- 37. Communications Devices Communications Devices • A communications device is any type of hardware p g capable of transmitting data, instructions, and information between a sending device and a receiving device receiving device • A dial‐up modem converts signals between analog and digital l Page 485 Discovering Computers 2011: Living in a Digital World 37 Chapter 9
- 38. Communications Devices Communications Devices • A digital modem sends and receives data and g information to and from a digital line DSL Cable modem modem Click to view Web Link, click Chapter 9, Click Web Link from left navigation navigation, then click Cable Modems below Chapter 9 Page 486 Discovering Computers 2011: Living in a Digital World 38 Chapter 9
- 39. Communications Devices Communications Devices Page 486 Discovering Computers 2011: Living in a Digital World 39 Figures 9‐26 – 9‐27 Chapter 9
- 40. Communications Devices Communications Devices • A wireless modem uses the cell phone network to y connect to the Internet wirelessly from a notebook computer, a smart phone, or other mobile device mobile device Page 487 Discovering Computers 2011: Living in a Digital World 40 Figure 9‐28 Chapter 9
- 41. Communications Devices Communications Devices • A network card enables a computer or device to access a network • Available in a variety of styles e ess e o ca ds • Wireless network cards often have an antenna Page 487 Discovering Computers 2011: Living in a Digital World 41 Figure 9‐29 Chapter 9
- 42. Communications Devices 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 2011: Living in a Digital World 42 Figure 9‐30 Chapter 9
- 43. Communications Devices 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 Click to view Web Link, click Chapter 9, Click Web Link from left navigation navigation, then click Wireless Routers below Chapter 9 Page 488 Discovering Computers 2011: Living in a Digital World 43 Figure 9‐31 Chapter 9
- 44. Communications Devices Communications Devices • A hub or switch connects several devices in a g network together Pages 488 – 489 Discovering Computers 2011: Living in a Digital World 44 Figure 9‐32 Chapter 9
- 45. Home Networks Home Networks • Home networks provide computers with the g p following capabilities: Connect to the Share a single high‐ Access files and Internet at the Internet at the speed Internet speed Internet programs on other programs on other Share peripherals Share peripherals same time connection computers Connect game Play multiplayer Subscribe to and consoles to the games use VoIP Internet Click to view Web Link, click Chapter 9, Click Web navigation, Link from left navigation then click Home Networks below Chapter 9 Page 489 Discovering Computers 2011: Living in a Digital World 45 Chapter 9
- 46. Home Networks Home Networks • Types of wired home networks: Ethernet Powerline cable Phoneline Page 489 Discovering Computers 2011: Living in a Digital World 46 Chapter 9
- 47. Home Networks Home Networks Page 490 Discovering Computers 2011: Living in a Digital World 47 Figure 9‐33 Chapter 9
- 48. Communications Channel Communications Channel • Th The amount of data that t f d t th t can travel over a communications channel sometimes is called the ti i ll d th bandwidth • Latency is the time it takes a y signal to travel from one location to another on a network • Transmission media carries one or more signals • B db d media transmit Broadband di t it multiple signals simultaneously Page 491 Discovering Computers 2011: Living in a Digital World 48 Figure 9‐34 Chapter 9
- 49. Physical Transmission Media Physical Transmission Media Page 492 Discovering Computers 2011: Living in a Digital World 49 Figure 9‐35 Chapter 9
- 50. Physical Transmission Media Physical Transmission Media Twisted‐pair cable i d i bl Fiber‐optic cable Coaxial cable Page 493 Discovering Computers 2011: Living in a Digital World 50 Figures 9‐36 – 9‐38 Chapter 9
- 51. Wireless Transmission Media Wireless Transmission Media Page 494 Discovering Computers 2011: Living in a Digital World 51 Figure 9‐39 Chapter 9
- 52. Wireless Transmission Media Wireless Transmission Media • Cellular radio is a form of broadcast radio that is y used widely for mobile communications Click to view Web Link, click Chapter 9, Click Web Link from left navigation navigation, then click Mobile TV below Chapter 9 Page 495 Discovering Computers 2011: Living in a Digital World 52 Figure 9‐40 Chapter 9
- 53. Wireless Transmission Media Wireless Transmission Media • Microwaves are radio waves that provide a high‐ p g speed signal transmission Page 496 Discovering Computers 2011: Living in a Digital World 53 Figure 9‐41 Chapter 9
- 54. Wireless Transmission Media 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 Discovering Computers 2011: Living in a Digital World 54 Figure 9‐42 Chapter 9
- 55. Video: Got Your Video Right Here Video: Got Your Video Right Here CLICK TO START CLICK TO START Discovering Computers 2011: Living in a Digital World 55 Chapter 9
- 56. Summary Overview of How to join communications t i t computers into a terminology and network applications Various communications devices, media, p and procedures Page 497 Discovering Computers 2011: Living in a Digital World 56 Chapter 9
- 57. Discovering Computers 2011 Living in a Digital World Chapter 9 Complete