Chapter 5: Telecommunications, Wireless Technologies, and
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Transcript Chapter 5: Telecommunications, Wireless Technologies, and
Chapter 5:
Telecommunications,
Wireless Technologies,
and Computer Networks
Succeeding with Technology:
Second Edition
Objectives
Understand the fundamentals of data
communications and the criteria for choosing a
communications medium
Explain how networking media, devices, and
software work together to provide data networking
services, and describe the benefits of various types
of media
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Objectives (continued)
List and describe the most popular forms of wireless
telecommunications technologies
List the different classifications of computer
networks and their defining characteristics, and
understand the basics of wireless home networking
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Fundamentals of Telecommunications
Communications
Signal
Transmission of a signal by way of a medium
Contains message comprised of data and
information
Communication medium
Anything that carries a signal between a sender and
a receiver
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Telecommunications and Data
Communications
Telecommunications
Electronic transmission of signals for
communications
Data communications
Electronic transmission and reception of digital data
Telecommunications network
Connects communications and computing devices
Networking media
Anything that carries an electronic signal
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Characteristics of Telecommunications
Analog signal
Fluctuates continuously
Digital signal
Discrete voltage
State is either high or low
Bandwidth
Data transmission rate
Measured in bits per second (bps)
Broadband
Connection that is always on or active
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Networking Media, Devices, and
Software – Networking Media
Twisted pair cable
Consists of pairs of twisted wires covered with an
insulating layer
Coaxial cable
Consists of an inner conductor wire surrounded by
insulation, a conductive shield, and a cover
Fiber-optic cable
Consists of thousands of extremely thin strands of
glass or plastic bound together in a sheathing
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Networking Devices
Modems
Modulates and demodulates signals
Cable modem
Provides Internet access over a cable television
network
DSL modem
Provides high-speed Internet service over
telephone lines
Network adapter
Computer circuit board, PC Card, or USB device
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Network Control Devices
Hubs
Used as a central point for connecting a series of
computers
Switches
Fundamental part of most networks
Repeaters
Connect multiple network segments
Bridges
Connect two or more network segments
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Network Control Devices
(continued)
Gateways
Network points that act as an entrance to another
network
Routers
Can divide a single network into two logically
separate networks
Wireless access point
Receives and transmits data to wireless adapters
Firewall
Device or software that filters the information
coming onto a network
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Industrial Telecommunications
Media and Devices
Microwave transmission
Also called terrestrial microwave
Line-of-sight medium
Communications satellite
Basically a microwave station placed in outer space
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Industrial Hardware
T1 line
Carries twenty-four 64-Kbps signals on one line
T3 line
Carries 672 signals on one line
Devices commonly used to control and protect
industrial-level telecommunications:
Multiplexer
Communications processor
Encryption devices
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Networking Software
Monitors the load, or amount of traffic, on the
network
Can provide data security and privacy
Network administrator
Person responsible for setting up and maintaining
the network
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Networking Software (continued)
Network Operating Systems
Perform same functions for network as operating
system software performs for a computer
Network Management Software
Facilitates monitoring of individual computers and
shared hardware
Communications Protocols and Standards
Ethernet: most widely used network standard for
private networks
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Wireless Telecommunications
Technology - Cell Phone
Technologies
Cellular network
A radio network
Geographic area is divided into cells with a
transceiver antenna and station at the center of
each cell
Cellular carrier
Company that builds and maintains cellular network
Provides cell phone service to the public
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Cellular Service Plans
Calling plans are defined by usage in three time
frames:
Whenever, or anytime, minutes with no time
restrictions
Weeknight minutes
Monday through Friday, 9:00 p.m. to 5:59 a.m. or
6:59 a.m.
Weekend minutes
Saturday 12:00 a.m. to Sunday 11:59 p.m.
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Pagers
Small, lightweight devices that receive signals from
transmitters
Types of paging systems
National and regional systems
Set up transmission towers to cover large
geographic areas
On-site paging systems
Use small desktop transmitters to send pages over
a small wireless network
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Global Positioning Systems
Uses satellites to pinpoint the location of objects on
earth
Using a GPS receiver and a network of 24 satellites
GPS can tell exact location of receiver on the earth’s
surface
GPS
Originally developed for national security and later
extended for public use
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Wireless Fidelity and WiMAX
Wireless fidelity (Wi-Fi)
Makes use of access points to wirelessly connect
users to networks within a range of 250–1000
Standards
Known as the 802.11 family of standards
Developed by the Institute of Electrical and
Electronics Engineers (IEEE)
Developed to support wireless computer networking
within a limited range at broadband speeds
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Wireless Fidelity and WiMAX
(continued)
WiMAX
Known as IEEE 802.16
Faster and longer range than Wi-Fi
WiMAX antenna has 31-mile range
Perfect for city-wide Internet access
Seattle’s Space Needle has a WiMAX antenna
Intel and Nokia are strongly supporting WiMAX
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Bluetooth
Enables digital devices to communicate directly with
each other wirelessly over short distances
Communicates at speeds of up to 1 Mbps within a
range of up to 33 feet (10 meters)
Can connect devices to a computer network using
access points like Wi-Fi
Bluetooth and Wi-Fi
Compete in some areas, but have unique qualities
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Infrared Transmission
Involves sending signals through the air via light
waves
Slower than both Bluetooth and Wi-Fi
Uses light rather than broadcast technology
Ideal for secure data transmissions
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Radio Frequency Identification
(RFID)
Uses tiny transponders in tags that can be
Attached to merchandise or other objects
Read using an RFID transceiver or reader for the
purpose of identification
Primarily used to track merchandise from supplier to
retailer to customer
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Networks and Distributed
Computing
Within a private network
Computing resources are shared in order to
maximize computing power
Computer
Includes devices for input, processing, storage, and
output
Components can be distributed throughout a
computer network
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Computer Networking Concepts
Nodes
Devices attached to a network
Workstations
Computers attached to a network
Local resources
Files, drives, or other peripheral devices connected
to the workstation and accessible via the network
Network resources
Workstation accesses over the network
Distributed Computing
Multiple remote computers working together
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Network Types
Personal area network (PAN)
Interconnecting personal information technology
devices
Local Area Network (LAN)
Connects computer systems within same building
Intranet
Uses protocols of the Internet and the Web within
the confines of a private network
Virtual Private Network (VPN)
Enables private Internet communications
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Network Types (continued)
Metropolitan area network (MAN)
Connects networks within a city or metropolitan-size
area into a larger high-speed network
Wide area network (WAN)
Connects LANs and MANs between cities, across
country, and around the world
Global Networks
A WAN that crosses an international border
Electronic Data Interchange (EDI)
Connects corporate computer systems
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Home Networks
Allow residents to
Share a single Internet connection
Share a single printer between computers
Share files such as images, music, and programs
Back up copies of important files to another PC for
safekeeping
Participate in multiplayer games.
Share output from devices such as a DVD player or
Webcam
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Summary
Telecommunications
Refers to the electronic transmission of signals for
communication
Types of cables used in telecommunications
Twisted pair cables, coaxial cable, and fiber optic
cable
Networking devices include
Modems, network adapters, network control
devices, RFID devices, and pagers
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Summary (continued)
Cellular network
Radio network
Geographic area is divided into cells with a
transceiver antenna (tower) and station at the center
of each cell
Server computers
Used to distribute data, files, and programs to users,
or clients, on the network
Home networks
Used to share hardware, files, and a common
Internet connection
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