Transcript chap01 - unix.eng.ua.edu

Telecommunications
Overview
Chapter 1
Objectives
In this chapter, you will learn to:
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Define communication and telecommunication
Illustrate components of a communication system
Understand the difference between voice, video, and
data
telecommunications
Describe how telecommunication is used in a variety of
industries
Identify careers available to telecommunications
professionals
Identify the organizations responsible for establishing
significant telecommunications standards and policies
What is communication?
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The Romans used the Latin word communicare
when they meant "to make common, to share,
or to impart.”
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Communication is the sharing of information
or messages between two or more entities.
Elements of a Communication
System
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Source - the originator of the message,
whether it is a person or machine.
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Transmitter - the equipment that modifies the
message (either data or voice) into the form
required for transmission.
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Communications channel - the means of
carrying the signal from the source to the
destination.
Elements of a Communication
System
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Transmission media - may be physical, like
a copper wire or fiber optic cable, or
atmospheric, like radio waves.
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Receiver - is the device that captures the
message from the communications channel
and converts it into a form that the person or
machine at the destination can understand.
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Destination - the person or machine to
whom the message is directed
Elements of a Communication
System
Flow of Messages
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Simplex - the type of communication in which
messages flow in only one direction, from source to
destination.
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Half-duplex communication - occurs when
messages travel in both directions between the
source and the destination, but in only one direction
at a time.
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Full-duplex communication - messages can travel
over the communications channel in both directions
simultaneously.
Flow of Messages
Relative Number of Sources and
Destinations
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One-to-one communication - a single source
sends information to a single destination.
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One-to-many communication - a single
source simultaneously sends information to
multiple destinations.
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Many-to-many communication - occurs when
many sources issue messages to many
destinations.
Relative Number of Sources and
Destinations
What is Telecommunication?
Communication that spans a distance.
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Voice telecommunication - using electrical signals to
transmit human voice across a distance, such as
telephones and radio broadcasts.
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Video telecommunication - the electrically-based
transmission of moving pictures and sound across a
distance.
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Data telecommunication - the use of electrical signals
to exchange encoded information between computerized
devices across a distance.
What is Telecommunication?
Voice
The telephony infrastructure includes crosscontinental fiber optic cable to facilitate international
voice telecommunications and national and regional
cabling to connect long distance calls.
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It includes numerous local, regional, and national switching
centers where phone calls are routed to their destinations by
computerized telephone switches.
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It also includes local connections (up to three miles in length)
to residences and businesses capable of greater connection
speed and volume than ever before.
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Finally, it includes the sophisticated telephone equipment
and applications that users rely on.
Data
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Telegraph - one of the first data
telecommunications inventions, uses wire to
convey electrical pulses that represent letters or
numbers over a distance.
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Newer data telecommunications technology is
not only faster, but also ensures better
accuracy due to more reliable transmission
media and techniques that enable the receiver
to monitor the integrity of the data it has
received.
Data
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Present-day data telecommunications technologies
include:
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Encoded information transmitted over traditional telephone lines
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Encoded information saved to fixed media, such as a hard disk,
floppy disk, or CD ROM
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Encoded information exchanged between two computers that are
directly connected by a single cable
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Encoded information exchanged by a group of connected
computers on a network
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Encoded information exchanged by two devices over radio waves
Types of Telecommunications
Companies
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Service providers - those that supply the
communications channels for voice and data
transmission.
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Equipment providers - those that supply the
user and connectivity equipment, such as
telephones.
Growth of the Telecommunications
Industry
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The United States government recently released a report
citing the number of high-speed lines connecting
individuals and businesses to the Internet increased 36%
during the first half of the year 2001, for a total of 9.6
million high-speed connections.
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The number of minutes Americans spend on interstate
long-distance telephone calls has quadrupled in the last
25 years to a total of 600 billion minutes.
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As of July 2001, the number of computers that provide
files and Web pages to users on the Internet had grown
to over 125 million, maintaining a 63% annual growth
rate.
Financial Services
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Call center - a facility dedicated to fielding customer
calls.
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Interactive voice response (IVR) system - a
method of sending information over the telephone by
pressing buttons in response to recorded voice
prompts, to answer routine questions.
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Automatic call distributor (ACD) - uses
computerized devices attached to the phone lines to
automatically route calls to specific phone
extensions.
Financial Services
Utilities
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Recent deregulation (the introduction of competition for
services) in the utilities industry has made
telecommunications even more critical to this industry.
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To persuade their customers not to choose another utility
provider, utility companies must strive harder to please
their customers, in part by answering questions as
promptly as possible.
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An advanced call center at a utilities company typically
uses both an ACD and an IVR.
Manufacturing
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The use of advanced voice, video, and data
telecommunications in manufacturing has resulted in
faster and more efficient production of goods and at the
same time it has also increased global competition.
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Supply chain management, an electronic means for
connecting a manufacturer with its suppliers and
distributors is a notable example of the use of
telecommunications in the manufacturing industry.
Transportation
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Examples of the transportation industry’s use of
telecommunications include:
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computerized flight control for airport traffic
software that issues maps and directions based on a given
starting point and destination
government-sponsored transportation hotlines that inform
callers about road construction and hazardous road
conditions
systems for suggesting the most efficient route between
multiple locations
Retail
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E-business - the use of data
telecommunications to conduct business
transactions.
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The apparel and sportswear segment of the
retail industry uses particularly sophisticated
and unique telecommunications technology for
their online business.
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Before the products even reach a retailer’s
point of sale (such as a Web site),
telecommunications technology helps with
manufacturing, quality control, inventory,
distribution, and product shipping.
Healthcare
Telemedicine - a field that brings patients and
healthcare professionals together by
exchanging voice, video, and data over
distances when they can’t meet face-to-face.
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Improves the quality of healthcare because
ailments can often be diagnosed and treated
faster.
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Also streamlines the record-keeping process
for clinicians who spend a great deal of time
entering data about their cases.
Government and Education
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Many government agencies use advanced
telecommunications to provide faster and easier
access to public services.
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Telecommunications also plays a significant
role in education. In South Carolina, a large
public school district is improving education
through distance learning.
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Distance learning - the use of telecommunications
technology to inform, educate, or train students
across distances.
New Frontiers for
Telecommunications Technology
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Fiber optic cable - a transmission media that
contains thin strands of fiber in its core and
uses pulses of light to convey signals.
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Capable of carrying higher amounts of data,
voice, or video within a given time span than
any other type of media.
New Frontiers for
Telecommunications Technology
cont’d
Careers in Telecommunications
No matter what type of telecommunications
position you seek, the following will serve you
well:
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The ability to install, maintain, and troubleshoot
the system of cables and wires that carry
telecommunications services
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A thorough knowledge of the public telephone
network, and the carriers and regulations that are
part of it
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Familiarity with enhanced telephone services
(such as IVR and ACD)
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A mastery of the basic principles of electricity
Careers in Telecommunications
No matter what type of telecommunications
position you seek, the following will serve
you well:
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A clear understanding of how computers accept and
interpret data from other computers over a network
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The ability to design, install, and troubleshoot basic
networks
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An understanding of how the Internet works
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Familiarity with wireless transmission methods
Careers in Telecommunications
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Areas within the field of telecommunications
that you might consider specializing in:
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Networked convergence of voice, video, and data
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Electronics and circuit design and engineering
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Development of telephony and computer applications
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Wireless telephony and networking
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Information security
Careers in Telecommunications
Telecommunications Standard
Organization
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Standards - documented agreements containing
technical specifications or other precise criteria that
stipulate how a particular product or service should be
designed or performed.
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American National Standards Institute (ANSI) ensures that the test results from one manufacturer can
be accurately compared to other manufacturers’ results.
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Both ANSI and ITU are involved in setting standards for
Integrated Services Digital Network (ISDN)
communications.
ANSI
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The ANSI (American National Standards
Institute) - an organization composed of over
a thousand representatives from industry and
government who together determine standards
for the electronics industry.
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ANSI does not dictate that manufacturers
comply with their standards, but requests them
to voluntarily comply.
TIA and EIA
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The EIA (Electronics Industry Alliance) - is a
trade organization composed of representatives
from electronics manufacturing firms across the
United States.
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TIA (Telecommunications Industry
Association) - focuses on standards for
information technology, wireless, satellite, fiber
optics, and telephone equipment.
IEEE
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IEEE (Institute of Electrical and Electronic
Engineers) - an international society composed
of engineering professionals.
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Its goals are to promote development and
education in the electrical engineering and
computer science fields.
ATIS
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ATIS (The Association for
Telecommunications Industry Solutions) - a
North American trade association made of
thousands of companies that provide
communications equipment and services.
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Its membership reviews emerging technology
and agrees on standards and operating
procedures to ensure that services and
equipment supplied by multiple companies can
be easily integrated.
ISO
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ISO (International Organization for
Standardization) - a collection of standards
organizations representing 130 countries with
its headquarters located in Geneva,
Switzerland.
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Its goal is to establish international
technological standards to facilitate global
exchange of information and barrier-free trade.
ITU
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The ITU (International
Telecommunications Union) - a
specialized United Nations agency that
regulates international telecommunication
usage, including radio and TV frequencies,
satellite and telephony specifications,
networking infrastructure, and tariffs applied
to global communication.
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Provides developing countries with technical
expertise and equipment to advance their
technological base.
U.S. Government Regulatory and
Legislative Bodies
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Federal Communications Commission (FCC)
- founded in 1934 in response to the growth and
need for control over the telecommunications
industry, is the primary national regulatory
agency involved in telecommunications.
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Public Service Commission (PSC) - the
states’ equivalent to the FCC.
Summary
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Communication is the conveyance and understanding of
meaningful information from one entity to another.
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Data telecommunication refers to use of electrical signals
to exchange encoded information between computerized
devices across a distance.
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Within the field of telecommunications, professionals
typically divide its services into three categories: voice,
video, and data.
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The telephone is the primary means of transmitting and
receiving voice signals.