Transcript Why Study Computers? - Radford University | Virginia

Chapter 5
Telecom, Wireless &
Networks
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Please discontinue use of cell
phone and turn off ringer
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Fundamentals
Media, Devices, and Software
Wireless Telecommunications
Networks and Distributed Computing
5.1
Fundamentals of
Telecommunications
Key Terms
• Telecommunications
• Networking media
• Analog signal
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• Digital signal
• Bandwidth
• Broadband
Telecommunications
 Telecommunications: The electronic
transmission of signals over a medium
for communications.
(cables or air)
Sender and Receiver must “speak” the same language.
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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
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Signal Frequency
 Frequency: the speed at which a signal
changes from high to low (Figure 5.4)
 Bandwidth: the range of signal frequencies
that can be sent over a given medium at the
same time.
 Often expressed as bits per second
 Broadband: faster than 200Kbps
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5.2
Networking Media,
Devices, and Software
The fundamental components of
telecommunications networks
Key Terms
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Twisted pair cable
Coaxial cable
Fiber-optic cable
Radio wave
Modem
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Network adapter
Microwave transmission
Communications satellite
Ethernet
Networking Media
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Twisted Pair Cable
Used for traditional phone lines, twisted pairs of
wires in plastic sheathing.
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Coaxial Cable
Used for home cable TV, thick copper core wire
– faster than twisted pair.
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Fiber Optic Cable
Thin strands of glass are used to send light beams
– highest bandwidth cable, most expensive.
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Radio Waves
Electromagnetic waves transmitted through the air
at various frequencies.
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Radio Waves (Figure 5.7)
 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.nrpb.org/understand/radiowaves/radiowaves.htm
http://electronics.howstuffworks.com/radio-spectrum1.htm
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300 GHz
30 GHz
2.9 GHz
EHF
SHF
UHF
Deep space radio communications (2.29-2.3 GHz)
Wi-fi Wireless Networks (2.4 GHz)
Global Positioning System 1.23 and 1.58 GHz
Air traffic Control (960-1,215 MHz)
900-MHz cordless phones
Cell Phones (824-849 MHz)
328.6 MHz
VHF
30 MHz
HF
CB Radio (26.96-27.41 MHz)
MF
AM Radio (535-1700 kHz)
3 MHz
300kHz
30 kHz
10 kHz
TV CH 7-13 (174-220 MHz)
FM Radio (88-108 MHz)
TV CH 2-6 (54-88 MHz)
Cordless Phones (40-50 MHz)
LF
VLF
The Radio Spectrum
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http://www.fcc.gov/oet/spectrum/
Networking Devices
 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.
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Networking Devices
 Network Control Devices:
 Hub/Switch
 Controls flow of data between
devices on a network
 Router
 Routs packets to destinations and
connects one network to another
 Wireless Access Point
 Allows devices to connect
wirelessly to a wired network
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Microwave Communications
High-frequency radio signals sent
up to 30 miles through the air.
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Microwave Communications
Line-of-sight communications
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Microwave Communications
Satellite Transmission
Line-of-sight required
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Networking Software
 Network administrators are
responsible for setting up and
maintaining the network.
 A network operating system
coordinates the network components
to support telecommunications.
 Ethernet is the most widely used
network standard for private networks.
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Review
1) Does 88.9 FM use an analog or digital
signal?
2) Does a cell phone use an analog or digital
signal?
3)Which type of cable has the highest
bandwidth?
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5.3
Wireless
Telecommunications
Technologies
Key Terms
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Cellular network
Cellular carrier
Global positioning system
Wireless fidelity (wi-fi)
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• WiMAX
• Bluetooth
• Radio frequency identification
Cell Phone Technologies
 A cellular network is a radio network in
which a geographic area is divided into
cells, with a transmission tower and
station at the center of each cell, to
support mobile communications.
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Cell Phone Technologies
 A cellular carrier is a company that
builds and maintains a cellular
network and provides cell phone
service to the public.
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GSM and CDMA
CDMA
GSM
Verizon
Sprint
Nextel
Cingular
AT&T
T-Mobile
 Digital networking standards for
cell phone networks are GSM
and CDMA.
 GSM is the most popular global
standard for mobile phones
 The CDMA networking standard
is predominantly used in the
United States where it is in equal
competition with GSM.
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GSM and CDMA
 GSM Phones include a subscriber
identity module (SIM) for security and
convenient data transfer between
phones.
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Cell Phone Technologies
 Consumers choose a carrier based
on coverage area, handsets
available, and services provided –
service contracts are typically for
two years.
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Cell Phone Technologies
 Learn about Service Plans,
Handsets, Features, and Services
by clicking the logos below.
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Cell Phone Technologies
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Cell Phone Technologies
 Cell phone accessories provide added
features for example…
 A 2 GB mini SD memory card can provide ample storage
digital photos, music, and video files.
 A Bluetooth headset allows you to interact with your
phone without taking it out of your pocket.
 Car chargers allow you to
charge your cell phone from
your car power supply.
 Assorted cases protect cell
phones from damage and
make them handy to access.
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Wireless Technologies
 The Global Positioning System
(GPS) uses satellites to pinpoint the
location of receivers on earth.
Aircraft Navigation
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Wireless Technologies
 The Global Positioning System
(GPS) uses satellites to pinpoint the
location of receivers on earth.
Seacraft Autopilot
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Wireless Technologies
 The Global Positioning System
(GPS) uses satellites to pinpoint the
location of receivers on earth. Automobile Navigation
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Wireless Technologies
 The Global Positioning System
(GPS) uses satellites to pinpoint the
location of receivers on earth. Handheld Navigation
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Wireless Technologies
 The Global Positioning System
(GPS) uses satellites to pinpoint the
location of receivers on earth.
Child Safety
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Wirless Technologies
 The Global Positioning System
(GPS) uses satellites to pinpoint the
location of receivers on earth.
Emergency Call
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Wireless Technologies
 Wireless Fidelity (IEEE 802.11), or Wi-fi, is
wireless networking technology that makes use
of access points to connect devices to
networks.
• 250-1,000 ft range
• 802.11b 4.5 Mbps
• 802.11g 11 Mbps
• www.boingo.com
Access
Point
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• http://talgov.com/cit
ytlh/utilities/ubcs/c
anopy.html
Wireless Technologies
 WiMAX (IEEE 802.16) is the
next generation broadband
technology that is both faster and
has a longer range than Wi-fi –
31 miles!
Seattle’s Space Needle To
Become WiMax Antenna
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http://en.wikipedia.org/wiki/WiMAX
Wireless Technologies
 Bluetooth is wireless technology
that enables a wide variety of
digital devices to communicate
directly.
• 33 ft range
• 1 Mbps
• www.bluetooth.com
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Bluetooth
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Wireless Technologies
 Infrared (IrDA) technology utilizes infrared
rays to send data over a short distance
wirelessly.
• 14 ft range
• Narrow-angle cone (30o)
• Line-of-sight
• 4-16 Mbps
• www.mzoop.com
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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 14 ft
4 Mbps
Infrared
Point-topoint
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Wireless Technologies
 Radio Frequency ID (RFID) uses
tiny transponders in tags that can
be attached to merchandise or
other objects and read using an
RFID receiver or reader for the
purpose of identification.
 Privacy issues hold this
technology back from item-level
labeling and barcode
replacement.
http://www.rfidjournal.com/
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Review
4)What technology is able to
display your current location on a
map?
5)What is today’s most popular
wireless network standard?
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5.4
Networks and Distributed
Computing
Key Terms
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Personal Area Network
Local Area Network
Intranet
Virtual Private Network
Metropolitan Area Network
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• Wide Area Network
Computer Network Concepts
 Distributed Computing
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
Network Types
 Personal Area Network (PAN)
 The wireless interconnection of
personal information technology
devices within the range of an
individual.
 Mostly associated with Bluetooth
technology
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http://www.scottevest.com/v3_product_info/features.shtml
Network Types
 Personal Area Network (PAN) – Alternate
Definition
 The human body is used to conduct a minimal
electric current to transfer information from one
original PAN was
individual’s device to another’s. The
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
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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”
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Network Types
 Local Area Network (LAN)
 Connects computer systems and devices
within a common geographic area
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Local Area Network
switch
Wireless
access point
Star
topology
System Administrator
Bus
topology
Servers
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Network Types
 Intranet
 A private network that utilizes Internet
and Web protocols and software.
 Virtual Private Network (VPN)
 Uses the Internet to connect an
organization’s networks dispersed around
the world into one large intranet.
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Network Types
 A Metropolitan Area Network
(MAN) connects networks within
a city or metropolitan-size area
into a larger high-speed network.
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Network Types
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
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Network Types
 A Global Network (International
Network) is a WAN that crosses
National boundaries.
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Network Types
 Electronic Data Interchange, or EDI, uses
networked systems and follows standards
and procedures that allow output from one
system to be processed directly as input to
other systems, without human participation.
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Installing Home Wi-fi
 Requirements
 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 home media: http://www.apple.com/airportexpress
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Wireless Access
Point / Router
Cable Modem
To Cable Co.
Chapter 5 Questions?
Don’t forget to turn
your phone on!!
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