Understanding Computer Communications and Networks: Components, Devices, and Standards - P, Study notes of Computer Science

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Discovering Computers 2009 Chapter 9 Communicati ons and Networks Chapter 9 Objectives Discuss the components required for successful communications Discuss the components required for successful communications Identify various sending and receiving devices Identify various sending and receiving devices Describe uses of computer communicationsDescribe uses of computer communications List advantages of using a networkList advantages of using a network Differentiate among client/server, peer-to-peer, and P2P networks Differentiate among client/server, peer-to-peer, and P2P networks Describe the various network communications standards Describe the various network communications standards Explain the purpose of communications software Explain the purpose of communications software Describe various types of lines for communications over the telephone network Describe various types of lines for communications over the telephone network Describe commonly used communications devices Describe commonly used communications devices Discuss different ways to set up a home network Discuss different ways to set up a home network Identify various physical and wireless transmission media Identify various physical and wireless transmission media Uses of Computer Communications What are some uses of communications technology? p. 462 Uses of Computer Communications What are wireless messaging services? p. 463 - 464 Wireless instant messaging allows wireless mobile devices to exchange messages Text messaging allows users to send and receive short text messages on a phone or other mobile device Picture/video messaging allows users to send graphics, pictures, video clips, sound files, and short text messages Uses of Computer Communications What are _______________________________ p. 464-465 Fig. 9-4  allows wireless connection to Internet in public location  3G and 4G networks  _______________is a coffee house that provides computers with Internet access wireless Internet access points Cybercafé Uses of Computer Communications p. 468 Fig. 9-8  ___________________is voice message converted to digital form  _____________________describe standardized software that enables programmers to create applications that communicate with other remote computers over the Internet or on an internal business network Voice mail Web services Networks What is a network? p. 469 Fig. 9-9  Collection of computers and devices connected via communications devices and transmission media Networks Network classifications  ____________is a network in limited geographical area such as home or office building  Wireless ____________  _____________________________ connects _____s in city or town  _____________________________ LAN LAN (WLAN) Metropolitan area network (MAN) LA N is a network that covers large geographic area using many types of media Wide area network (WAN)  ____________is world’s largest_________WANInternet Network p. 472 Fig. 9-13 2. _____________: Cable forms closed loop (ring), with all computers and devices arranged along ring. Data travels from device to device around entire ring, in one direction Network Topology Ring network Network p. 472 Fig. 9-13 3. _____________: All devices connect to a central device (hub or switch) All data transferred from one computer to another passes through hub or switch. Network Topology Star network Networks What is an___________? p. 475 _________ allows customers or suppliers to access part of company’s __________ Typically includes connection to Internet Makes information accessible to employees Internal network that uses Internet technologies intranet Extranet intranet Network Communications Standards p. 476 ___________ Short-range radio waves transmit data between Bluetooth devices • Contains a small chip to communicate with each other. _______ is a specification allows data to be transferred wirelessly via short-range radio waves. Bluetooth WAB _______ specification allows data to be transferred wirelessly via infrared light waves. IrDA Network Communications Standards p. 476 ___________ uses radio signals to communicate with a tag placed in an object • Radio Frequency Identification. _______ is a standard that specifies how wireless devices communicate over the air in a wide area. • Worldwide Interoperability for Microwave Access RFID WiMAX _______ allow wireless mobile devices to access Internet. • Wireless Application Protocol • Use client/server network. WAP Communications Software What is communications software? p. 480  Programs that help users establish connection to Internet, other network, or another computer  Programs that help users manage transmission of data, instructions, and information  Programs that provide an interface for users to communicate with one another Communications Over the Telephone Network Dedicated lines p. 481  _______________ Integrated Services Digital Network. Require both ends of the connection have ________ modem. ISDN lines ISDN  __________Digital Subscriber Line For the small business or home user DSL  __________Fiber to the Premises Use fiber-optic cable to provide extremely high- speed Internet access FTTP Communications Over the Telephone Network Dedicated lines p. 481  _______________ Long-distance digital telephone lines that carry multiple signals over a single communications line. T1 line is most popular. T-Carrier lines  __________ Asynchronous Transfer Mode Very high speed. Large amounts of traffic use this. ATM Communications Devices _________________ p. 485  Converts digital signals to analog signals and vice versa  Usually in the form of an adapter card Dial-up modem Communications Devices What is a________________?  Allows access to the Web wirelessly from a notebook computer, a smart phone, or other mobile device  Typically use the same waves used by cellular telephones wireless modem Communications Devices What is a______________? p. 486 - 487 Fig. 9-30  Adapter card, PC Card, ExpressCard module, USB network adapter, or flash card that enables computer or device to access network  Sometimes called network interface card (NIC) network card Communications Devices What is a_____________________? p. 487 Fig. 9-31  Central communications device that allows computers and devices to transfer data wirelessly among themselves or wirelessly to a wired network wireless access point Home Networks What is a home network?  Multiple computers connected in home  Several types of home networks  Ethernet — connect computers via cable  Powerline cable — use electrical lines in house  Phoneline — use telephone lines Communications Channel What is a communications channel?  Transmission media on which data travels in communications system Bandwidth is amount of data that can travel over a communications channel Transmission media are materials or substances capable of carrying one or more signals Physical Transmission Media What is physical transmission media? p. 492 Fig. 9-36  Wire, cable, and other tangible materials used to send communications signals Wireless Transmission Media What is wireless transmission media? p. 494 Fig. 9-40  Used when inconvenient, impractical, or impossible to install cables  Includes Bluetooth and IrDA Wireless Transmission Media  ________________ distributes radio signals over long and short distances  ________________ is form of ________________ used for mobile communications Broadcast radio Cellular radio broadcast radio Wireless Transmission Media What is a __________station?  Earth-based reflective dish used for microwave communications  Must transmit in straight line with no obstructions microwave