discovering computers 2009 chapter 9 communications and networks
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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 sendingand receiving devices
Identify various sendingand 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 ofcommunications software
Explain the purpose ofcommunications 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 usedcommunications devices
Describe commonly usedcommunications devices
Discuss different ways to set upa home network
Discuss different ways to set upa home network
Identify various physical and wireless transmission media
Identify various physical and wireless transmission media
Communications
Communications
What are computer___________________? Process in which two or more computers or devices transfer data,
instructions, and information
communicationscommunications
__________________— initiates instruction to
transmit data, instructions, or
information
What is needed for successful communications?
Communications
p. 460 - 461
Communications device — connects the communications
channel to the receiving device
_________________
accepts transmission of data, instructions, or
information
Communications device — connects
the sending device to the communications
channel
__________________
media on which data, instructions, or
information travel
Sending deviceSending deviceCommunications channelCommunications channel
Receiving deviceReceiving device
Uses of Computer Communications
Uses of Computer CommunicationsWhat are some uses of communications technology?
p. 462
Uses of Computer CommunicationsWhat are wireless messaging services?
p. 463 - 464
Wireless instant Wireless instant messagingmessaging allows allows wireless mobile wireless mobile
devices to exchange devices to exchange messagesmessages
Text messagingText messagingallows users to send allows users to send
and receive short and receive short text messages on a text messages on a
phone or other phone or other mobile devicemobile device
Picture/video Picture/video messaging messaging allows allows
users to send users to send graphics, pictures, graphics, pictures, video clips, sound video clips, sound
files, and short text files, and short text messagesmessages
Uses of Computer CommunicationsWhat 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 pointswireless Internet access points
CybercaféCybercafé
Uses of Computer CommunicationsWhat is a _____________________________?
p. 466 Fig. 9-6
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 receiver’s geographic location.
global positioning system (GPS)global positioning system (GPS)
Uses of Computer Communications
p. 467 Fig. 9-7
_______________is software that allows people work together and share information
____________________is working with other users connected to a server
Web conference
CollaborationCollaboration
GroupwareGroupware
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 mailVoice mail
Web servicesWeb services
Networks
p. 469 Fig. 9-9
Networks
What is a network?
p. 469 Fig. 9-9
Collection of computers and devices connected via communications devices and transmissionmedia
Networks
Network classifications ____________is a network in limited geographical area
such as home or office building Wireless ____________
_____________________________ connects _____s in city or town
_____________________________
LANLAN
LAN (WLAN)LAN (WLAN)
Metropolitan area network (MAN)Metropolitan area network (MAN) LANLAN
is a network that covers large geographic area using many types of media is a network that covers large geographic area using many types of media
Wide area network (WAN)Wide area network (WAN)
____________is world’s largest_________WANWANInternetInternet
Network
p. 472 Fig. 9-13
_____________: One or more computers act as host computer and other computers access the host computer
_______________: Simple network that connects fewer than 10 computers. Each computer has equal capabilities
_________________________: Enables users to connect to each other’s hard disks and exchange files directly. Sometimes called a file sharing network.
Network Architectures
Client/ServerClient/Server
peer-to-peerpeer-to-peer
Internet peer-to-peer (P2P)Internet peer-to-peer (P2P)
Network
p. 472 Fig. 9-13
1. _____________: All computers and devices connect to central cable or bus
Network Topology: the layout of the computers in a network.
Bus networkBus network
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 networkRing 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 networkStar 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
intranetintranet
ExtranetExtranetintranetintranet
Network Communications Standards
p. 476
Network Communications Standards
p. 476
___________ technology allows computers to contend for access to network. No controlling computers or devices.
If two computers send data at same time, a collision occurs and computers must send again Bus topology, but sometimes star topology
_______________ technology controls access to network by requiring devices to pass a special signal, called token
EthernetEthernet
Token ringToken ring
Network Communications Standards
p. 476
_____________________________________________ technology transmits data by breaking it up into small pieces, or packets.
• Commonly used for Internet transmissions
_______________ is a family of standards for wireless LANs
TCP/IP (Transmission Control Protocol/Internet Protocol)TCP/IP (Transmission Control Protocol/Internet Protocol)
802.11 (Wi-Fi)802.11 (Wi-Fi)
Network Communications Standards
p. 476
___________ Short-range radio waves transmitdata 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.
BluetoothBluetooth
WABWAB
_______ specification allows data to be transferred wirelessly via infrared light waves.IrDAIrDA
Network Communications Standards
p. 476
___________ uses radio signals to communicatewith a tag placed in an object
• Radio Frequency Identification.
_______ is a standard that specifies how wirelessdevices communicate over the air in a wide area.
• Worldwide Interoperability for Microwave Access
RFIDRFID
WiMAXWiMAX
_______ allow wireless mobile devices to access Internet.
• Wireless Application Protocol• Use client/server network.
WAPWAP
Communications Software
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
p. 481 Fig. 9-23
Communications Over the Telephone Network
p. 481 Fig. 9-23
_______________________________________________:Worldwide telephone system that handles voice-oriented
telephone calls.
The entire telephone network uses digital technology.
But, the final link from the local telephone company to a home often uses analog.
public switched telephone network (PSTN)public switched telephone network (PSTN)
Communications Over the Telephone Network
Various lines that use the telephone network for data communications
p. 481
1. _______________ Temporary connection using telephone line for communications
Costs no more than making regular call Computers at any two locations can establish a
connection using modems and telephone network
dial-up linedial-up line
2. _______________ Always-on connection between two communications devices There are five types of lines.
Dedicated lineDedicated line
Communications Over the Telephone Network
Dedicated lines
p. 481
_______________ Integrated Services Digital Network.
Require both ends of the connection have ________ modem.
ISDN linesISDN lines
ISDNISDN
__________Digital Subscriber LineFor the small business or home user
DSLDSL
__________Fiber to the PremisesUse fiber-optic cable to provide extremely high-
speed Internet access
FTTPFTTP
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 linesT-Carrier lines
__________ Asynchronous Transfer ModeVery high speed.Large amounts of traffic use this.
ATMATM
Communications Devices
p. 484
Communications Devices
_________________
p. 485
Converts digital signals to analog signals and vice versa Usually in the form of an adapter card
Dial-up modemDial-up modem
Communications Devices
What are____________________ ?
p. 485
Communications devices that send and receive digital ISDN and DSL signals
Communications devices that send and receive digital ISDN and DSL signals
Usually external devices in which one end connects to a telephone line and the other
end connects to a port on the system unit
Usually external devices in which one end connects to a telephone line and the other
end connects to a port on the system unit
ISDN and DSL modemsISDN and DSL modems
Communications Devices
What is a_____________?
p. 484 - 486 Fig. 9-28
Sends and receives data over cable television network
Much faster than dial-up modem or ISDN
Sometimes called a broadband modem
cable modemcable 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 modemwireless 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 cardnetwork 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 pointwireless access point
Communications Devices
What is a____________? Connects computers and
transmits data to correct destination on network
Routers forward data on Internet using fastest available path
Some routers have a built-in hardware firewall
routerrouter
Communications Devices
What is a_______________? Device that provides central
point for cables in network
hub or switchhub or switch
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
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
Physical Transmission Media
p. 493 Fig. 9-37—9-38
______________cable consists of one or more twisted-pair wires bundled together. It is used for telephone systems and network cabling
_________cable consists of a single copper wire. It is often used for cable television wiring
Twisted-pairTwisted-pair
CoaxialCoaxial
Physical Transmission Media
What is __________cable?
Consists of dozens or hundreds of thin strands of glass or plastic
Capable of carrying significantly more data at faster speeds than wire cables
Less susceptible to interference (noise) and, therefore, more secure
fiber-opticfiber-optic
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 radioBroadcast radio
Cellular radioCellular radio
broadcast radiobroadcast radio
Wireless Transmission Media
What is a __________station? Earth-based
reflective dish used for microwave communications
Must transmit in straight line with no obstructions
microwavemicrowave
Wireless Transmission Media
What is a_______________________? Space station
that receives microwave signals from earth-based station, amplifies signals, and broadcasts signals back to any number of earth-based stations
communications satellitecommunications satellite
Summary of Communications and Networks
Chapter 9 Complete
Communications terminology and applications
Communications terminology and applications
How to join computers into a networkHow to join computers into a network
Various communications devices, media, and procedures
Various communications devices, media, and procedures
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