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