Wired and Wireless Communication

workablejeansMobile - Wireless

Nov 21, 2013 (3 years and 10 months ago)

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Computers Are
Your Future

© 2005 Prentice
-
Hall, Inc.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
2

Computers Are Your Future

Chapter 8


Wired and Wireless Communication

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
3

What You Will Learn About


The limitations of the public switched telephone network
(PSTN) for sending and receiving computer data


Multiplexing and digital telephony


Wireless transmission media


How convergence is blurring the boundaries among popular
communication devices


Home networking using wired and wireless communications
applications


Teleconferencing and videoconferencing technology


Telecommuting and workgroup computing

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
4


Connectivity

is the ability to link various media and
devices.

Connectivity

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
5

Wired Communication via the PSTN


The
public switched telephone network

(
PSTN
) is
the world telephone system.


It is used for data as well as voice communications.


Twisted
-
pair wire and fiber
-
optic cable provide the
connections for the system.


Home and business phones are connected to
subscriber
loop carriers

(
SLC
s).


The area serviced by SLCs is called the
local loop
.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
6

Multiplexing


Multiplexing
technology enables simultaneous multi
-
use of transmission lines.


Copper wire allows up to 24 simultaneous calls per wire.


Fiber
-
optic cable permits up to 43,384 calls per strand.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
7

Last Mile Technologies


The “last mile” refers to the phone lines that connect
homes and businesses to the local loop.


The inability of users to access the high
-
speed fiber
-
optic
cable creates a bottleneck of data called the
last mile
problem
.


Digital telephony technologies that use twisted
-
pair
wire are referred to as
last mile technologies
.


ISDN


DSL


Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
8

Wireless Transmission Media


Wireless transmission media

refers to the methods
of carrying data through the air or space using
infrared, radio, or microwave signals.

Infrared

Microwave

Radio

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
9

Infrared


Infrared

is a wireless transmission medium that
carries data via light beams.


Transmitter and receiver must be in line of sight.


An IrDa port is needed to use infrared with a computer.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
10

Radio


Radio

is a wireless transmission medium that carries
data via radio frequency signals.


Wireless LANs in a home or business are one type of radio
technology.


Radio signals can be long range (between cities or regions)
and short range (within a building).


Radio signals are susceptible to noise and electrical
interference.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
11

Microwaves


Microwaves

are high
-
frequency radio waves.


Much of long
-
distance telephone service is carried by
microwaves.


Microwaves travel in a straight line.


Microwave relay stations are built about 30 miles apart.


Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
12

Satellites


Satellites

are microwave relay stations suspended in
space.


They are positioned in
geosynchronous orbits.


Satellites use microwave signals to transmit data to
and from earth
-
based microwave relay stations.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
13

Cellular Telephones


Cellular telephones

enable calls to be placed through
a wireless telecommunications system.


Cellular phones use radio or infrared signals.


Cells

are limited geographic transmission areas.


A

mobile telephone switching office

(
MTSO
)
monitors the signal strength of cellular phones.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
14

Personal Communication Service (PCS)


Personal Communication Service

(
PCS
) refers to
digital cellular telephone service technologies.


Digital cellular phones offer:


Noise
-
free sound


Improved coverage


Protection from eavesdropping and phone fraud


Voice recognition


High
-
speed Internet access

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
15

Pagers


Pagers

work like a simple radio.


Pagers are:


Constantly listening for a specific signal from a transmitter


Either one
-
way (only receive signals) or two
-
way (send and
receive signals)


Declining in use due to the increase in cell phone use

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
16

Web
-
Enabled Devices


A
web
-
enabled device

is any device that can display
and respond to HTML or XML.


PDAs, cell phones, and tablet PCs are web
-
enabled
devices.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
17

Facsimile (Fax) Transmission


Fax transmission is the means of sending an image of
a document over telephone lines.


Fax modems support fax as well as data protocols.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
18

TV Internet Set
-
Tops



Internet TV is an Internet service that uses a TV to:


Broadcast TV programs


Send and receive e
-
mail


Access Web sites


Navigate the Internet using a remote control

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
19

Wired and Wireless Home Networks


Wired home networks use coaxial cable, telephone
wires, cat
-
5 wires, or the home’s electric power
wiring.


Wireless home networks use radio signals.

Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
20

Wired and Wireless Applications


Teleconferencing:


It is the simplest wired application for voice
communication
.


A telephone is used to conduct a conference between more
than two people who are separated by a distance.


Videoconferencing:


Two or more people can have a face
-
to
-
face meeting when
they are geographically separated
.


Cameras, a computer, and videoconferencing software are
used to conduct the conference
.


Computers Are Your Future Chapter 8

© 2005 Prentice
-
Hall, Inc

Slide
21

Wired and Wireless Applications


Telecommuting:


Telecommuting is performing work at home while being
linked to the office by telecommunications
-
equipped
computers.


The advantages of telecommuting include not having to
commute, flexible hours, more family time, and familiar
surroundings.


Workgroup Computing:


A workgroup is a group of individuals, working together on
a task, who are able to communicate and collaborate by
way of computers connected to a network.


Groupware

software is used by workgroups.