Communications and Networks by abdugreen

VIEWS: 15 PAGES: 57

									Discovering
    Computers 2010
    Living in a Digital World
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 2010: Living in a Digital World                            2
for Detailed Objectives                            Chapter 9
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 2010: Living in a Digital World                         3
for Detailed Objectives                                 Chapter 9
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 2010: Living in a Digital World             4
                                                Chapter 9
Communications




Pages 460 – 461   Discovering Computers 2010: Living in a Digital World   5
Figure 9-1                            Chapter 9
Uses of Computer Communications

                              Blogs              Chat rooms                          E-mail              Fax


                                                   Instant
                                FTP                                                Internet          Newsgroups
                                                  messaging


                                                   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,
           then click Wikis
           below Chapter 9
Page 462                                 Discovering Computers 2010: Living in a Digital World                    6
                                                             Chapter 9
Uses of Computer Communications

• Users can send and receive wireless messages
  using wireless messaging services




Pages 462 – 463   Discovering Computers 2010: Living in a Digital World   7
Figure 9-3                            Chapter 9
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

           Click to view Web Link,
           click Chapter 9, Click Web
           Link from left navigation,
           then click Video Messaging
           below Chapter 9
Pages 463 - 464                         Discovering Computers 2010: Living in a Digital World   8
                                                            Chapter 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 2010: Living in a Digital World   9
Figure 9-4                            Chapter 9
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 2010: Living in a Digital World   10
Figure 9-5                          Chapter 9
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
           Click to view Web Link,
           click Chapter 9, Click Web
           Link from left navigation,
           then click GPS
           below Chapter 9
Page 466                                Discovering Computers 2010: Living in a Digital World              11
                                                            Chapter 9
Uses of Computer Communications




Page 467     Discovering Computers 2010: Living in a Digital World   12
Figure 9-6                       Chapter 9
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 2010: Living in a Digital World            13
                                           Chapter 9
Uses of Computer Communications

• Collaboration software includes tools that enable
  users to share documents via online meetings and
  communicate with other connected users
                                          Online                             Web
                                         meetings                         conferences

                                                     Document
           Click to view Web Link,
                                                    management
           click Chapter 9, Click Web
           Link from left navigation,
           then click Microsoft Groove
                                                      systems
           below Chapter 9
Page 468                                   Discovering Computers 2010: Living in a Digital World   14
                                                               Chapter 9
Uses of Computer Communications




Page 468     Discovering Computers 2010: Living in a Digital World   15
Figure 9-7                       Chapter 9
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              Discovering Computers 2010: Living in a Digital World   16
Figure 9-8                                Chapter 9
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 2010: Living in a Digital World         17
                                                  Chapter 9
Networks




Page 470     Discovering Computers 2010: Living in a Digital World   18
Figure 9-9                       Chapter 9
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 2010: Living in a Digital World   19
Figures 9-10 – 9-11                       Chapter 9
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 2010: Living in a Digital World   20
Figure 9-12                        Chapter 9
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 2010: Living in a Digital World     21
Figures 9-13 – 9-14                                  Chapter 9
Networks

• P2P describes an Internet network on which users
  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,
              then click P2P
              below Chapter 9
Page 475                                   Discovering Computers 2010: Living in a Digital World   22
Figure 9-15                                                    Chapter 9
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 2010: Living in a Digital World                  23
Figures 9-16 – 9-18                           Chapter 9
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 2010: Living in a Digital World   24
                                          Chapter 9
Network Communications Standards

             Token
  Ethernet                                     TCP/IP                Wi-Fi
              ring

Bluetooth    UWB                                  IrDA               RFID


             WiMAX                               WAP

Page 477     Discovering Computers 2010: Living in a Digital World           25
                                 Chapter 9
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

           Click to view Web Link,
           click Chapter 9, Click Web
           Link from left navigation,
           then click Ethernet
           below Chapter 9
Page 478                                Discovering Computers 2010: Living in a Digital World   26
                                                            Chapter 9
Network Communications Standards




Page 479      Discovering Computers 2010: Living in a Digital World   27
Figure 9-19                       Chapter 9
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 2010: Living in a Digital World   28
Figure 9-20                            Chapter 9
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,
           then click RFID
           below Chapter 9
Pages 480 - 481                         Discovering Computers 2010: Living in a Digital World   29
                                                            Chapter 9
Network Communications Standards




Page 481      Discovering Computers 2010: Living in a Digital World   30
Figure 9-21                       Chapter 9
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 2010: Living in a Digital World           31
                                           Chapter 9
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 2010: Living in a Digital World   32
                                        Chapter 9
Communications Over
the Telephone Network
• The public switched telephone network (PSTN) is
  the worldwide telephone system




Pages 482 – 483   Discovering Computers 2010: Living in a Digital World   33
Figure 9-23                           Chapter 9
Communications Over
the Telephone Network

                  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,
           then click DSL
           below Chapter 9
Pages 483 - 485                         Discovering Computers 2010: Living in a Digital World           34
                                                            Chapter 9
Communications Over
the Telephone Network




Page 483      Discovering Computers 2010: Living in a Digital World   35
Figure 9-24                       Chapter 9
Communications Over
the Telephone Network
• ADSL connections transmit data downstream at a
  much faster rate than upstream




Page 484       Discovering Computers 2010: Living in a Digital World   36
Figure 9-25                        Chapter 9
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 2010: Living in a Digital World   37
                                   Chapter 9
Communications Devices

• A digital modem sends and receives data and
  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,
           then click Cable Modems
           below Chapter 9
Page 486                                Discovering Computers 2010: Living in a Digital World   38
                                                            Chapter 9
Communications Devices




Page 486              Discovering Computers 2010: Living in a Digital World   39
Figures 9-26 – 9-27                       Chapter 9
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 2010: Living in a Digital World   40
Figure 9-28                        Chapter 9
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             Discovering Computers 2010: Living in a Digital World   41
Figure 9-29                              Chapter 9
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 2010: Living in a Digital World   42
Figure 9-30                           Chapter 9
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,
              then click Wireless Routers
              below Chapter 9
Page 488                                    Discovering Computers 2010: Living in a Digital World   43
Figure 9-31                                                     Chapter 9
Communications Devices

• A hub or switch connects several devices in a
  network together




Pages 488 – 489   Discovering Computers 2010: Living in a Digital World   44
Figure 9-32                           Chapter 9
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


           Click to view Web Link,
           click Chapter 9, Click Web
           Link from left navigation,
           then click Home Networks
           below Chapter 9
Page 489                                    Discovering Computers 2010: Living in a Digital World                        45
                                                                Chapter 9
Home Networks

• Types of wired home networks:


           Ethernet                         Powerline cable



                          Phoneline


Page 489       Discovering Computers 2010: Living in a Digital World   46
                                   Chapter 9
Home Networks




Page 490      Discovering Computers 2010: Living in a Digital World   47
Figure 9-33                       Chapter 9
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                Discovering Computers 2010: Living in a Digital World   48
Figure 9-34                                 Chapter 9
Physical Transmission Media




Page 492      Discovering Computers 2010: Living in a Digital World   49
Figure 9-35                       Chapter 9
Physical Transmission Media
                      Twisted-pair cable



                                                                                       Fiber-optic cable




                        Coaxial cable




Page 493                                Discovering Computers 2010: Living in a Digital World              50
Figures 9-36 – 9-38                                         Chapter 9
Wireless Transmission Media




Page 494      Discovering Computers 2010: Living in a Digital World   51
Figure 9-39                       Chapter 9
Wireless Transmission Media

• Cellular radio is a form of broadcast radio that is
  used widely for mobile communications




              Click to view Web Link,
              click Chapter 9, Click Web
              Link from left navigation,
              then click Mobile TV
              below Chapter 9
Page 495                                   Discovering Computers 2010: Living in a Digital World   52
Figure 9-40                                                    Chapter 9
Wireless Transmission Media

• Microwaves are radio waves that provide a high-
  speed signal transmission




Page 496        Discovering Computers 2010: Living in a Digital World   53
Figure 9-41                         Chapter 9
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 2010: Living in a Digital World   54
Figure 9-42                             Chapter 9
Video: Got Your Video Right Here




                           CLICK TO START

            Discovering Computers 2010: Living in a Digital World   55
                                Chapter 9
Summary

             Overview of
                                                       How to join
           communications
                                                     computers into a
           terminology and
                                                        network
             applications

                           Various
                      communications
                       devices, media,
                      and procedures
Page 497            Discovering Computers 2010: Living in a Digital World   56
                                        Chapter 9
Discovering
    Computers 2010
    Living in a Digital World


    Chapter 9 Complete

								
To top