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Chapter 5 Study Outline
1 Fundamentals of Telecommunications
Communications – the transmission of a signal from a sender to a receiver by way of a medium such as
wires or radio waves.
Communications Medium – anything that carries a signal between a sender & receiver
1.1 Telecommunications and Data Communications
Telecommunications -- refers to the electronic transmission of signals for communications.
Examples: Some telecommunications devices that we interact with on a daily basis include telephones,
radios, TVs, and computers.
Data communications -- a specialized subset of telecommunications, refers to the electronic collection,
processing, and distribution of data, typically between computer systems
Telecommunications network -- connects communications and computing devices
Computer network -- a specific type of telecommunications network that connects computers and computer
systems for data communications
This chapter discusses the following components of telecommunications:
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Networking media: Anything that carries an electronic signal and creates an
interface between a sending device and a receiving device.
Networking hardware devices and networking software: Work together to
enable and control communications signals between communications and
computer devices.
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1.2 Characteristics of Telecommunications
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The characteristics of telecommunications components should be analyzed in terms of speed,
quality, and convenience.
Telecommunications can allow people to be more productive.
For example, being able to access and respond to e-mail during an hour-long daily commute on
the bus or train frees up an hour later in the day for going to the gym or some other productive
activity.
1.2.1 Types of Signals
If we measured the voltage on a telephone wire during a conversation, we would see something like Figure
5.4a. Notice that the figure shows a signal that continuously changes over time. This type of continuous
fluctuation between high and low voltage is called an analog signal.
In contrast, if we measured the voltage on cables used to connect PCs, we would probably see something
comparable to Figure 5.3b. The signal in Figure 5.3b at any given time is either high or low. This type of
discrete voltage state (either high or low) is called a digital signal. The two states are used to represent the
state of a bit, high for 1, and low for 0.
1.2.2 Transmission Capacities
Signal Frequency -- speed at which an electronic communications signal can change from high to low is
called the signal frequency
 A faster frequency means a faster data transmission rate. Signal frequency is measured in hertz
(Hz), or cycles per second.
 In computer networks, the data transmission rate is also referred to as the bandwidth and is
measured in bits per second (bps).
 Today’s bandwidth options fall into one of two categories: narrowband or broadband.
Bandwidth Options
 Broadband: Media advertised by Internet service providers as “high-speed.”
 Narrowband: Any medium with a speed less than 200 Kbps, typically the speeds
delivered by a 56 Kbps dial-up modem connection.
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TEAM NAME_Ramrod________________________________________
Members Present / Roles __DAVID, ZACH, JOHN, RYAN___________
2 Networking Media, Devices, and Software
2.1 Networking Media- Involves various types of media for
telecommunications networks
Media should support the needs of users
Be as costless as possible
2.1.1 Physical Cables
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Different physical cables offer a range of bandwidth from narrow to broadband
Cables have advantage over wireless
Cables are secure
Cables have to be installed, usually in an inconspicuous manner
2.1.1.1 Type of Cables
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2.1.2
Twisted-pair cable: twisted wires covered with an insulting layer. – used on most wired
networks
Coaxial cable: consists of an inner conductor wire surrounded by insulation, a
conductive shield and a cover. Was once the preferred wire of networks
Fiber-optic cable: consists of thousands of extremely thin strands of glass or plastic
bound together in a sheathing jacket. It transmits with light beams.
Radio Signals And Light
-Telecommunications signals can travel through air using radio waves and light.
- Radio wave is an electromagnetic wave transmitted through an antenna at different
frequencies.
-Microwaves are at the high end of the spectrum between 1 and 300GHz
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TEAM NAME____Back Row________________________
Members Present / Roles __ummm, not listed??_____________________
2.2 Networking Devices
2.2.1 Modem
A modem modulates and demodulates signals from one form to another, typically for the purpose
of connecting to the internet.
an external or internal device that converts analog and digital signals from one form to the other
Cable modem: provides internet access to PCs and computer networks over a cable television
network.
DSL modem: provides high speed internet service over telephone lines.
2.2.2 Network Adapters
A computer circuit board, PC Card, or USB device installed in a computing device so that it can
be connected to a network.
NIC Network interface card: is a circuit board or PC card that when installed provides a port for
the device to connect to a wired network with traditional network cables.
Wireless Adapters: can be a circuit card, PC card, or an external device that connects through a
USB port that provides an external antenna to send and receive network radio signals.
2.2.3 Network Control Devices
Hubs: Small electronic boxes that are used as a central point for connecting a series of computers.
A bud sends the signal from each computer to all the other computers on the network.
Switches: make it possible for several users to send information over a network at the same time
without slowing each other down.
Repeaters: Connect multiple network segments, listening to each segment and repeating the
signal heard on one segment onto every other segment connected to the repeater.
Bridges: Connect two or more network segments as a repeater does but bridges also help regulate
traffic.
Gateway: network points that act as an entrance to another network.
Routers: advanced networking components that can divide single network into two logically
separate networks
Wireless access point: connects to a wired network and receive and transmit data to wireless
adapters installed in computers.
Firewall: is a device or software that filters the information coming onto a network to protect the
network computes form hackers, viruses, and other unwanted network traffic.
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TEAM NAME__Dr. H did this one for you! _______________________________
3 Wireless Telecommunications Technologies
Wireless technologies put the world at your fingertips on cell phones, handheld and notebook computers,
and other special-purpose devices, wherever you may travel.
3.1 Cell Phone Technologies
Today’s cell phone services are founded on and also limited by cellular network technology. A cellular
network is a radio network in which a geographic area is divided into cells with a transceiver antenna
(tower) and station at the center of each cell, to support mobile communications. If a cell phone user travels
from one cell to another, the system judges the cell phone’s location based on its signal strength, and passes
the phone connection from one cell tower to the next. The signals from the cells are transmitted to a
receiver and integrated into the regular phone system.
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Cell Phone
Technologies:
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Cellular networks and carriers: A cellular carrier is a company that builds
and maintains a cellular network and provides cell phone service to the
public.
Cellular service plans: Calling plans are defined by usage in three time
frames: whenever, or anytime, minutes with no time restrictions, weeknight
minutes, and weekend minutes.
Cellular handsets, features, and services: Cell phone manufacturers work
hand-in hand with carriers to provide the functionality for the services they
offer, while the carriers work to provide services for the new technologies
that manufacturers develop.
3.2 Pagers
Pagers are small, lightweight devices that receive signals from transmitters. Different pagers have varying
levels of functionality. The most basic pager simply beeps, flashes, or vibrates to get the attention of the
user. More sophisticated pagers accept numeric or text messages. Some pagers allow the owner to listen to
voice messages, or send messages as well as receive them.
3.3 Global Positioning Systems
A Global Positioning System (GPS) uses satellites to pinpoint the location of objects on earth. Using a GPS
receiver and a network of 24 satellites, the GPS can tell you the exact location of the receiver on the earth’s
surface. The GPS satellites orbit the earth in such a way that at any given time and location on earth, four
satellites are visible to a GPS receiver. By measuring the distance from the receiver to each satellite, and
calculating those distances with the known position of each satellite, the receiver is able to determine its
location on Earth. Like the Internet, GPS was originally developed for national security and later extended
for public use.
3.4 Wireless Fidelity and WiMax
Wireless fidelity (Wi-Fi) is wireless networking technology that makes use of access points to wirelessly
connect users to networks within a range of 250–1000 feet (75–300 meters). Wi-Fi technology uses
wireless access points that broadcast network traffic using radio frequencies to computers equipped with
Wi-Fi cards or adapters. Wi-Fi has a maximum range of about 1000 feet (300 meters) in open areas and
250 to 400 feet (75 to 125 meters) in closed areas. Areas covered by Wi-Fi are often called hotspots.
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Wireless Telecommunications Technologies (continued)
3.5 Bluetooth (Amy Suttle)
Bluetooth enables a wide assortment of digital devices to communicate directly
with each other wireless over short distances
Enables devices communicate directly with each others in pairs. UP to 7 devices
can be paired simultaneously, which can be created automatically or manually
For example, you can talk on your wireless headset while your phone is in your
back pocket
Bluetooth communicates at speeds of up to 1Mbps within range of up to 33 feet (10
meters)
Manufactures are installing Bluetooth chips in a wide varity of communications and
computer appliances to allow device-to-device connections
For example 6 participants sitting around a conference table could exchange notes
or business cards among their notebook, tablet or handheld computers.
3.6 Infrared Transmission (Victoria Painter)
Another type of wireless transmission, called infrared transmission, involves
sending signals through the air via light waves (these light waves are longer then
the visible spectrum but shorter than radio waves).
It requires a direct line-of-sight connection and operates at short distances.
 Your television remote control uses infrared to send signals to the TV.
Although infrared is slower than both Bluetooth and Wi-Fi, it has an advantage in
that it uses light rather than broadcast technology. This makes it ideal for secure
data transmissions that you do not wish to have intercepted by spying devices.
 For instance, transferring credit card information to a cash register could
be performed with infrared because the signal is directed to specific
device and is less likely to be hacked.
 ZOOP, a South Korean company, provides a universal mobile payment
system for cell phone users in South Korea and Japan. The system
stores credit card information on the user’s cell phone that can be
transferred to cash registers, vending machines, and mass transit
vehicles to pay for merchandise and services with a push of a button and
an infrared signal.
Infrared transmission refers to energy in the region of the electromagnetic
radiation spectrum at wavelengths longer than those of visible light, but shorter
than those of radio waves. Correspondingly, infrared frequencies are higher than
those of microwaves, but lower than those of visible light.
 Wireless (local area networks)
 Home-entertainment remote-control boxes
 Links between notebook computers and desktop computers
 Cordless modem
 Intrusion detectors
 Motion detectors
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Fire sensors
Night-vision systems
Medical diagnostic equipment
Missile guidance systems
Geological monitoring devices
3.7 Radio Frequency Identification
Radio Frequency Identification -- http://en.wikipedia.org/wiki/RFID#RFID_tags
- An automatic identification method
- Relies on storing and remotely retrieving data using transponders
- An RFID tag is an object that can be applied or incorporated into an product,
animal, or person for identification purposes
- Tags contain two parts – an integrated circuit and an antenna
- Uses: Passports, transportation payments, product tracking, animal
identification, inventory systems, human implants, and in libraries, as well as
many other uses
- Potential uses: Replacing barcodes, telemetry, and patient identification
- Security concerns: Illicit tracking, exposing personal location privacy and
corporate/military/DOD security; the use of cryptography to prevent tag cloning
- Most chips can be disabled by physical means; can prevent power from being
received, etc.
- Three varieties: Passive, active, and semi-passive
- Passive: Have no internal power supply; the antenna has to be designed to collect
power from incoming signals and transmit the outbound signal
- Active: Have their own internal power source; used to power integrated circuits and
broadcast the signal to the reader
- Semi-passive: Have their own power source; the battery is used only to power the
microchip and not broadcast a signal
- Example: In Live Free or Die Hard, when “The Warlock” communicates with Senior
Officer John McClane (Bruce Willis) through “his” frequency -- 66.6 megahertz.
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4 Networks and Distributed Computing
4.1 Computer Networking Concepts: a communications network
that connects two or more computers for the purpose of sharing
data, hardware, and software resources. They can range in size
from 2 computers to millions. For computers to communicate
they must follow protocols.
4.1.1 Distributed Computing: a method of computer processing in which
different parts of a program run simultaneously on two or more
computers that are communicating with each other over a network.
Distributed computing is a type of segmented or parallel computing,
but the latter term is most commonly used to refer to processing in
which different parts of a program run simultaneously on two or more
processors that are part of the same computer.
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TEAM NAME___The Blue Foxes______________________________________
Members Present / Roles __Kara: typist/e-mail sender; Thomas: Definitions, Owen:
website,__All: Main points___________________________
4.2 Network Types
4.2.1 Personal Area Network (PAN)-The interconnection of personal information technology devices, typically
wirelessly, within the range of an individual(around 33 feet or 10 meters)
4.2.2 Local Area Network (LAN)- A network that connects computer
systems and devices within the same building or local
geographical area.
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Can include personal computers, printers, and servers.
(VPN)Virtual Private Network- uses a technique called tunneling to
securely send private network data over the internet. May be used to
connect an organization’s networks dispersed around the world into one
large intranet.
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Intranet- uses the protocols of the Internet and the Web-TCPI/IP and
HTTP, along with internet services such as web browsers- within the
confines of a private network.
- Can be extended to specific individuals outside the network, such
as customers, partners, or suppliers, in an arrangement call
extranet
4.2.3 Metropolitan Area Network (MAN)- Connects networks within a
city or metropolitan-size area into a larger high-speed network.
-often accts as a stepping stone, to larger network.
4.2.4 Wide Area Network (WAN)-Connects LANs and MANs between
cities, across country, and around the world using microwave
and satellite transmition or s
4.2.5 Global Networks:
-A WAN that crosses an international border is considered a global or
international network. The internet is most known global network.
- Global networks must follow international laws, which regulate the electronic
flow of data across international boundaries, often called transborder data flow.
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Electronic Data Interchange (EDI)- uses network systems and follows standards
and procedures that allow output from one system to be processed directly as
input to other systems, without human participation. With EDI, computers of
customers, retailers, manufacturers, and suppliers can be connected.
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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 computer for safekeeping.
-Participate in multi-player games.
-Share output from devices such as a DVD player or Webcam.
~ Home networking technologies:
 Phone-line networking- called HomePNA (Phone-networking alliance),
takes advantage of existing phone wiring in a residence
 Power-line networking (HomePLC)- Takes advantage of the home’s
existing power lines and electrical outlets to connect computers. Divides
up the household electrical system and uses some for network
communications and the others for electrical current.
 Wireless Network: with speeds up to 54 Mbps, home wireless networks
easily support everything a typical home user might want to do on a
home network.
Related sites.
 4.2.1 Personal Area Network (PAN)http://en.wikipedia.org/wiki/Personal_area_network
 4.2.2 Local Area Network (LAN)http://en.wikipedia.org/wiki/Local_area_network
 Virtual Private Network (VPN)http://en.wikipedia.org/wiki/Virtual_private_network
 Intranet- http://en.wikipedia.org/wiki/intranet
 4.2.3 Metropolitan Area Network (MAN)http://en.wikipedia.org/wiki/Metropolitan_area_network
 4.2.4 Wide Area Network (WAN)http://en.wikipedia.org/wiki/Wide_area_network
 4.2.5 Global networks- www.gnet.org
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