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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
