Transcript CH05 - TechMinded

Telecom & Networks
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Please turn your
cell phone off.
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Fundamentals
Telecom Components
Computer Networks
Network Applications
© 2004 Ken Baldauf, All rights reserved.
Fundamentals of
Telecommunications
© 2004 Ken Baldauf, All rights reserved.
Telecommunications
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Telecommunications: The electronic
transmission of signals over a medium
for communications.
© 2004 Ken Baldauf, All rights reserved.
Types of Signals
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Analog Signal:
transmit sound
using continuously
varying levels of
voltage.
Digital Signal:
transmits data using
two discrete states of
voltage: high and low
© 2004 Ken Baldauf, All rights reserved.
Signal Frequency
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Frequency: the speed at which a signal
changes from high to low.
Bandwidth: the range of signal frequencies
that can be sent over a given medium at the
same time.
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Often expressed as bits per second
Broadband: faster than 200Kbps
© 2004 Ken Baldauf, All rights reserved.
Review: Fundamentals
© 2004 Ken Baldauf, All rights reserved.
Network Media,
Devices, and Software
The fundamental components
of telecommunications
networks
© 2004 Ken Baldauf, All rights reserved.
Networking Media
Twisted Pair
Cable
 Coaxial Cable
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Fiber Optic
Cable
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Radio Waves
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© 2004 Ken Baldauf, All rights reserved.
Radio Waves
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Radio waves use differing frequencies to carry
many types of information:
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AM & FM Radio
Short Wave & CB Radio
Television Broadcasts
Garage Doors Openers
Baby Monitors
Cordless Phones
Cell Phones
Radio Controlled Cars and Airplanes
Global Positioning Systems
Wireless Computer Networks
Microwave Communications
http://www.fcc.gov/oet/spectrum/
http://www.nrpb.org/understand/radiowaves/radiowaves.htm
http://electronics.howstuffworks.com/radio-spectrum1.htm
© 2004 Ken Baldauf, All rights reserved.
Microwave Communications
High-frequency radio signals sent
up to 30 miles through the air.
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© 2004 Ken Baldauf, All rights reserved.
Microwave Communications
Line-of-sight communications
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© 2004 Ken Baldauf, All rights reserved.
Microwave Communications
SatelliteTransmission
Line-of-sight required
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Global Positioning System
(GPS)
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GPS: uses satellites to pinpoint the
location of receivers on earth.
Aircraft Navigation
© 2004 Ken Baldauf, All rights reserved.
GPS
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GPS: uses satellites to pinpoint the
location of receivers on earth.
Seacraft Autopilot
© 2004 Ken Baldauf, All rights reserved.
GPS
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GPS: uses satellites to pinpoint the
location of receivers on earth. Automobile Navigation
© 2004 Ken Baldauf, All rights reserved.
GPS
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GPS: uses satellites to pinpoint the
location of receivers on earth.
Computing
© 2004 Ken Baldauf, All rights reserved.
GPS
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GPS: uses satellites to pinpoint the
location of receivers on earth. Handheld Navigation
© 2004 Ken Baldauf, All rights reserved.
GPS
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GPS: uses satellites to pinpoint the
location of receivers on earth.
Child Safety
© 2004 Ken Baldauf, All rights reserved.
GPS
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GPS: uses satellites to pinpoint the
location of receivers on earth.
Emergency Call
© 2004 Ken Baldauf, All rights reserved.
GPS
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GPS: uses satellites to pinpoint the
location of receivers on earth. Auto-emergency Call
© 2004 Ken Baldauf, All rights reserved.
Wireless Fidelity (Wi-Fi)
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Wi-Fi: devices that communicate wirelessly
using the 802.11 protocol.
• 250-1,000 ft range
• 802.11b 4.5 Mbps
• 802.11g 11 Mbps
• www.boingo.com
Access
Point
• http://talgov.com/cit
ytlh/utilities/ubcs/c
anopy.html
© 2004 Ken Baldauf, All rights reserved.
Bluetooth
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Bluetooth: Wireless technology
that enables a wide variety of
digital devices to communicate
directly.
• 33 ft range
• 1 Mbps
• www.bluetooth.com
© 2004 Ken Baldauf, All rights reserved.
Infrared (IRDA)
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Infrared technology utilizes infrared rays to
send data over a short distance wirelessly.
• 4 ft range
• Narrow-angle cone (30o)
• Line-of-sight
• 4-16 Mbps
• www.mzoop.com
© 2004 Ken Baldauf, All rights reserved.
Wireless Comparison
Wi-fi
Access
point
centered
LAN
Omnidirection
Through
250 ft
obstructions range
indoors
11 Mbps
Bluetooth Point-topoint
Omnidirection
Through
33 ft
obstructions
1 Mbps
Narrowangle
Line-of-sight 4 ft
4 Mbps
Infrared
Point-topoint
© 2004 Ken Baldauf, All rights reserved.
Networking Devices
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Modem: modulates and
demodulates signals from one form
to another.
Network Adapter: Expansion card,
or external device installed on a
computing device used to connect
to a network.
© 2004 Ken Baldauf, All rights reserved.
Networking Devices
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Network Control Devices:
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Hub/Switch
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Router
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Controls flow of data between
devices on a network
Routs packets to destinations and
connects one network to another
Wireless Access Point
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Allows devices to connect
wirelessly to a wired network
© 2004 Ken Baldauf, All rights reserved.
Radio Frequency Identification
(RFID)
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RFID Device: tiny microprocessor combined
with antenna able to store and broadcast
identifying information to an RFID reader.
Currently on hold until security issues are
addressed.
http://www.technologyreview.com/articles/visualize0304.asp?trk=nl
© 2004 Ken Baldauf, All rights reserved.
Review: Telecom Components
© 2004 Ken Baldauf, All rights reserved.
Networks and Distributed
Computing
© 2004 Ken Baldauf, All rights reserved.
Networking Software
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Network Operating System (NOS)
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Protocols
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an agreed-upon format for transferring data between
devices.
Standard
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system software that controls the communications
between computer systems and devices on a network.
an agreed-upon way of doing something within an
industry.
Ethernet
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the most widely used network standard for private
networks.
© 2004 Ken Baldauf, All rights reserved.
Computer Network Concepts
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Distributed Computing
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Refers to a computing environment that
includes multiple remote computers that
work together to solve problems and
provide services.
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Database Servers
Application Servers
File Servers
Print Servers
© 2004 Ken Baldauf, All rights reserved.
Types of Computer Networks
© 2004 Ken Baldauf, All rights reserved.
Local Area Network (LAN)
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Local Area Network (LAN)
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Connects computer systems and devices
within a common geographic area
© 2004 Ken Baldauf, All rights reserved.
Local Area Network
switch
Wireless
access point
Star
topology
System Administrator
Bus
topology
Servers
© 2004 Ken Baldauf, All rights reserved.
WAN
Wide Area Network
Connects LANs between
cities, cross country, and
around the world using
microwave and satellite
transmission or telephone
lines.
router
FSU Tallahassee LAN
router
FSU Panama City LAN
© 2004 Ken Baldauf, All rights reserved.
Global Area Network (GAN)
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Global Area Network (GAN)
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An International network
© 2004 Ken Baldauf, All rights reserved.
Personal Area Network (PAN)
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Personal Area Network (PAN)
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The wireless interconnection of
personal information technology
devices within the range of an
individual.
Mostly associated with Bluetooth
technology
http://www.scottevest.com/v3_product_info/features.shtml
© 2004 Ken Baldauf, All rights reserved.
Network Technologies
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Intranet
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A private network that utilizes Internet
and Web protocols and software.
Virtual Private Network (VPN)
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Uses the Internet to connect an
organization’s networks dispersed around
the world into one large intranet.
© 2004 Ken Baldauf, All rights reserved.
PAN – Alternative Definition
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Personal Area Network (PAN)
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The human body is used to conduct a minimal
electric current to transfer information from one
individual to another.
The original PAN was
designed by Thomas
Zimmerman and allowed
users to pass digital
electronic information
through touch, by transferring
information from one
person’s device to another’s,
running a subtle current
through the body.
http://www.almaden.ibm.com/cs/user/pan/pan.html
© 2004 Ken Baldauf, All rights reserved.
Exchange emails through handshake
TWO Japanese telecoms giants have developed technology that turns the human body
into a broadband-paced link that allows e-mail addresses to be exchanged through a
simple handshake, a report said Monday.
The technology, developed by Nippon Telegraph and Telephone Corp. and its subsidiary
NTT DoCoMo Inc., uses the body's conductivity and adds the smarts of a personal digital
assistant (PDA), the Nihon Keizai Shimbun said.
A device attached to a PDA can send and receive weak electrical signals through people,
with human bodies as communications circuits, the paper said, citing sources close to
the companies.
Apparel and handbags have their own conductivity, allowing an electrical connection to a
PDA that can remain in one's pocket, the paper said.
In this way, people can exchange e-mail addresses, names and phone numbers while
shaking hands, with the data automatically written into both their PDAs, the paper said.
The companies have confirmed in an experiment that data can be transmitted at 10
megabits per second, comparable to the speed of a broadband Internet connection, it
said.
The technology could allow data communications through door knobs, switches, desks
and chairs, the paper said. It could pave the way to one day being able to pass through
railway ticket gates or entering secure buildings with a simple touch. It could also get a
computer to start up with the proper settings as soon as the user sat down, the paper
said.
Agence France-Presse
See also
“Microsoft patents body power”
© 2004 Ken Baldauf, All rights reserved.
Review: Networks
© 2004 Ken Baldauf, All rights reserved.
Setting Up a Wireless Home
Network
© 2004 Ken Baldauf, All rights reserved.
Installing Home Wi-fi
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Requirements
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High-speed Internet
Cable Modem or DSL
Modem (provided be
ISP)
Wireless Access
Point/Router
Wireless adapters for
each device.
Additional Access Points
as needed.
Wireless Access
Point / Router
Cable Modem
To Cable Co.
http://www.linksys.com/
© 2004 Ken Baldauf, All rights reserved.
Dangers of Home Wi-fi
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Neighbors
Hackers
Wireless Access
Point / Router
Cable Modem
Wireless Access
Point / Router
Cable
To
Co.
Cable Modem
To Cable Co.
© 2004 Ken Baldauf, All rights reserved.
Dangers of Home Wi-fi
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Neighbors
Hackers
Passer byes
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www.wardriving.com
Wireless Access
Point / Router
Cable Modem
To Cable Co.
© 2004 Ken Baldauf, All rights reserved.
Dangers of Home Wi-fi
War Driving Kit
© 2004 Ken Baldauf, All rights reserved.
Securing Home Wi-fi
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Change the default SSID
(network name).
Change the default
password needed to access
a wireless device.
Enable MAC address
filtering.
Disable the SSID broadcast
option.
Enable WEP or WPA
encryption
Install Firewall Software
Wireless Access
Point / Router
Cable Modem
To Cable Co.
© 2004 Ken Baldauf, All rights reserved.
Review: Wi-fi
© 2004 Ken Baldauf, All rights reserved.
Questions?
Don’t forget to turn your
phone back on!!
© 2004 Ken Baldauf, All rights reserved.