Communication Technologies CIS 505 Business Information * Welcome to Communication Technologies. In this lesson, we will discuss Business Information. Next slide. Topics AudioDataImageVideoPerformance measures * The following topics will be covered in this lesson: Audio; Data; Image; Video; and Performance measures. Next slide. AudioOverviewMeasured in bandwidthCan be represented digitallyApplicationsHuman voiceTelephoneTelemarketingVoice mailAudio teleconferencingEntertainment radioNetworking ImplicationsPBXCentrex * The audio service supports applications based on sounds, usually of human voice. The primary application using audio service is telephone communication. Other applications include telemarketing, voice mail, audio teleconferencing, and entertainment radio. The quality of sound is characterized mainly by bandwidth. Audio information can also be represented digitally. The most effective way of managing voice requirements is to tie all of the phones at a given site into a single system. There are two main alternatives for this: The private branch exchange, and Centrex. The private bank exchange, or PBX, is an on-premise switching facility, owned or leased by an organization that interconnects the telephones within the facility and provides access to the public telephone system. Centrex is a telephone company offering that provides the same sort of service as a PBX but performs the switching function in equipment located in the telephone company’s central office. Either a PBX or Centrex facility can support a wide variety of voice-related services. Both voice mail and audio teleconferencing can be supported by either approach. Next slide. OverviewExamining Forms of Business InformationHow impact is measuredForms of business informationTypes of servicesInformation SourcesDigitalNumericalTextBinaryAnalog * It is important to understand how information communication relates to business requirements. A first step in this understanding is to examine the various forms of business information. Our examination covers the following topics: How the impact of information sources on communications systems is measured, The nature of the four major forms of business information, The types of business services that relate to each of these forms of information, and An introductory look at the implications of these services from the point of view of the communications requirements that they generate. Information sources can produce information in digital or analog form. Digital information is presented as a sequence of discrete symbols from a finite alphabet. Examples are text, numerical data, and binary data. Analog information is a continuous signal that can take on a continuum of values. An example is the electrical signal coming out of a microphone when someone speaks into it. Next slide. DataOverviewFinite alphabet of symbolsTextNumerical informationCharacter stringsBinary dataUsing a databaseNetwor ...

1. Communication
Technologies
CIS 505
Business Information
*
Welcome to Communication Technologies. In this lesson, we
will discuss Business Information.
Next slide.
Topics
AudioDataImageVideoPerformance measures
*
The following topics will be covered in this lesson:
Audio;
Data;
Image;
Video; and

2. Performance measures.
Next slide.
AudioOverviewMeasured in bandwidthCan be represented
digitallyApplicationsHuman
voiceTelephoneTelemarketingVoice mailAudio
teleconferencingEntertainment radioNetworking
ImplicationsPBXCentrex
*
The audio service supports applications based on sounds,
usually of human voice. The primary application using audio
service is telephone communication. Other applications include
telemarketing, voice mail, audio teleconferencing, and
entertainment radio. The quality of sound is characterized
mainly by bandwidth. Audio information can also be
represented digitally.
The most effective way of managing voice requirements is to tie
all of the phones at a given site into a single system. There are
two main alternatives for this:
The private branch exchange, and
Centrex.
The private bank exchange, or PBX, is an on-premise switching
facility, owned or leased by an organization that interconnects
the telephones within the facility and provides access to the
public telephone system.
Centrex is a telephone company offering that provides the same
sort of service as a PBX but performs the switching function in

3. equipment located in the telephone company’s central office.
Either a PBX or Centrex facility can support a wide variety of
voice-related services. Both voice mail and audio
teleconferencing can be supported by either approach.
Next slide.
OverviewExamining Forms of Business InformationHow impact
is measuredForms of business informationTypes of
servicesInformation SourcesDigitalNumericalTextBinaryAnalog
*
It is important to understand how information communication
relates to business requirements. A first step in this
understanding is to examine the various forms of business
information. Our examination covers the following topics:
How the impact of information sources on communications
systems is measured,
The nature of the four major forms of business information,
The types of business services that relate to each of these forms
of information, and
An introductory look at the implications of these services from
the point of view of the communications requirements that they
generate.
Information sources can produce information in digital or
analog form. Digital information is presented as a sequence of
discrete symbols from a finite alphabet. Examples are text,

4. numerical data, and binary data.
Analog information is a continuous signal that can take on a
continuum of values. An example is the electrical signal
coming out of a microphone when someone speaks into it.
Next slide.
DataOverviewFinite alphabet of symbolsTextNumerical
informationCharacter stringsBinary dataUsing a
databaseNetworking Implications
*
Data consists of information that can be represented by a finite
alphabet of symbols, such as the digits zero through nine or the
symbols represented on a terminal keyboard. Common
examples of data include text and numerical information.
A familiar example of digital data is text or character strings.
While textual data are most convenient for human beings, they
cannot, in character form, be easily stored or transmitted by
data processing and communications systems. Such systems are
designed for binary data. Thus a number of codes have been
devised by which characters are represented by a sequence of
bits. Text, numerical data, and other types of data are typically
organized into a database.
The networking requirements for supporting data applications in
an organization vary widely.
Next slide.

5. ImageImage RepresentationVectorRasterGray scale imageImage
and Document FormatsJPEGGIFPDFPostscriptNetworking
ImplicationsCompressionResponse time and throughput
*
The image service supports the communication of individual
pictures, charts, or drawings. Image-based applications include
facsimile, computer-aided design, publishing, and medical
imaging.
There are a variety of techniques used to represent image
formation. These fall into two main categories:
Vector graphics, and
Raster graphics.
With vector graphics, images are represented as a collection of
straight and curved line segments. Vector graphics involve the
use of binary codes to represent object type, size, and
orientation.
With raster graphics, images are represented as a two-
dimensional array of spots, called pixels.
A gray scale image is produced if each pixel is defined by more
than one bit, representing shades of gray. Gray scale can also
be used in vector graphics to define the gray scale of line
segments or the interior of closed objects such as rectangles.
Images can also be defined in color. There are a number of
schemes in use for this purpose. One example is RGB, which
stands for red-green-blue, in which each pixel or image area is
defined by three values, one for each of the three colors.

6. The most widely used format for raster-scan images is referred
to as JPEG. The Joint Photographic Experts Group is a
collaborative standards-making effort between ISO and ITU-T.
The JPEG standard is designed to be general purpose, meeting a
variety of needs such as desktop publishing, graphic arts,
newspaper wire photo transmission, and medical imaging. JPEG
is appropriate for high quality images.
Another format that is often seen on the Web is Graphics
Interchange Format, or GIF. This is an eight-bit color format
that can display up to two-hundred-fifty-six colors and is
generally useful for non-photographic images.
There are also two popular document formats that are suitable
for documents that include text and images. The Portable
Document Format, or PDF, is widely used on the Web.
Postscript is a page description language that is built into many
desktop printers.
The various configurations by which image information is used
and communicated do not fundamentally differ from the
configurations used for text and numerical data.
The number of bits needed to represent an image can be reduced
by the use of image compression techniques. Compression
ratios of eight-to-sixteen bits are readily achieved.
Even with compression, the number of bits to be transmitted for
image formation is large. As usual, there are two concerns:
Response time, and
Throughput.
Next slide.

7. VideoOverviewSequence of picturesRaster-scan imagesElectron
beam Scanning processInterlacingNetworking
ImplicationsTelevisionTeleconferencingClosed circuit
TVMultimedia
*
The video service carries sequences of pictures in time. In
essence, video makes use of a sequence of raster-scan images.
To produce a picture on the screen, an electron beam scans
across the surface of the screen from left to right and top to
bottom. At the end of the scan line, the beam is swept rapidly
back to the left. When the beam reaches the bottom, it is swept
rapidly back to the top. The beam is turned off during the
retrace intervals.
To achieve adequate resolution, the beam produces a total of
four-hundred-eighty three horizontal lines at a rate of thirty
complete scans of the screen per-second. To provide a flicker
free image without increasing the bandwidth requirement, a
technique known as interlacing is used.
Applications based on video include instructional and
entertainment television, teleconferencing, closed circuit TV,
and multimedia.
Next slide.
Performance MeasuresResponse TimesSystem reaction to an
inputCost of better response timeComputer processing
powerCompeting requirementsUser response timeSystem
response time Critical for transaction processing
systemsThroughputIncreased capabilitiesDemands of services

8. *
In the following section we will discuss two key parameters
related to performance requirements:
Response time, and
Throughput.
Response time is the time it takes a system to react to a given
input. In general, it is the time it takes for the system to respond
to a request to perform a particular task.
Ideally, one would like the response time for any application to
be short. However, it is almost always the case that shorter
response time imposes greater cost. This cost comes from the
following sources:
Computer processing power, and
Competing requirements.
Thus, the value of a given level of response time must be
assessed versus the cost of achieving that response time.
Studies have shown that when a computer and a user interact at
a pace that ensures that neither has to wait for the other,
productivity increases significantly. The cost of work done on
the computer drops, and quality tends to improve.
A transaction consists of a user command from a terminal and
the system’s reply. It is the fundamental unit of work for only
system users. It can be divided into two time sequences:
User response time, and
System response time.

9. In terms of types of computer-based information systems, rapid
response time is most critical for transaction processing
systems. The output of management information systems and
decision support systems is generally a report or the results of
some modeling exercise. In these cases, rapid turnaround is not
essential.
The implication in terms of communications is this:
If there is a communications facility between an interactive user
and the application and a rapid response time is required, then
the communications system must be designed so that its
contribution to delay is compatible with that requirement.
Another area where response time has become critical is the use
of the World Wide Web, either over the Internet or over a
corporate intranet. Response times can be gauged based on the
level of user involvement in the session.
The trend toward higher and higher transmission speed makes
possible increased support for different services that once
seemed too demanding for digital communications. To make
effective use of these new capabilities, it is essential to have a
sense of the demands each service puts on the storage and
communications of integrated information systems. Services
can be grouped into data, audio, image, and video, whose
demands vary greatly.
Next slide.
SummaryAudioDataImageVideoPerformance measures
*

10. We have now reached the end of this lesson. Let’s take a look at
what we’ve covered.
We started the lecture off by examining that audio service
supports applications based on sounds, usually of human voice.
The primary application using audio service is telephone
communication. Other applications include telemarketing, voice
mail, audio teleconferencing, and entertainment radio. The
quality of sound is characterized mainly by bandwidth. Audio
information can also be represented digitally.
Next, we saw that data consists of information that can be
represented by a finite alphabet of symbols, such as the digits
zero through nine or the symbols represented on a terminal
keyboard. Common examples of data include text and
numerical information.
We then discussed that the image service supports the
communication of individual pictures, charts, or drawings.
Image-based applications include facsimile, computer-aided
design, publishing, and medical imaging.
Lastly, we discovered that video service carries sequences of
pictures in time. In essence, video makes use of a sequence of
raster-scan images. To produce a picture on the screen, an
electron beam scans across the surface of the screen from left to
right and top to bottom.
This completes this lesson.
Communication

11. Technologies
CIS 505
Introduction
*
Welcome to Communication Technologies. In this lesson, we
will discuss Introducing Communications Technologies.
Next slide.
TopicsInformation and communicationData communications and
networkingConvergence and unified communicationsThe nature
of business information requirementsDistributed
applicationsNetworksThe transmission of information;
Management issuesStandards
*
Information and communication;
Data communications and networking;
Convergence and unified communications;
The nature of business information requirements;
Distributed applications;
Networks;
The transmission of information;
Management issues; and

12. Standards.
Next slide.
OverviewInformation and
CommunicationComputersCommunication
technologiesDemographicsTransforming businessUsing
management structures to gain
advantageNetworkingOvercoming organizational difficulties
*
A confluence of computers, communication technologies, and
demographics is transforming the way any enterprise conducts
itself and carries out its organizational mandate. At the heart of
the transformation is information. So fundamental is
information communication technology to business success that
it is emerging as the foundation of a new strategy now taking
shape in American businesses—using management structures to
gain a competitive advantage.
Companies are breaking down divisional walls and flattening
top-heavy management pyramids to create new corporate
structures that help them compete more effectively. The
technology that is making much of this possible is networking.
Communication technology helps companies overcome the
following kinds of organizational difficulties:
Geographically dispersed networks,
Top-heavy companies, and
Barriers between divisions.

13. Next slide.
Data Communications and NetworkingTrendsTrafficExpanded
servicesNew technologyFaster and cheaperIntelligent
networksThe Internet’s influenceEver-increasing mobility
*
Effective and efficient data communication and networking
facilities are vital to any enterprise. Three different forces have
consistently driven the architecture and evolution of data
communication and networking facilities:
Traffic growth,
Development of new services, and
Advances in technology.
Communication traffic has been growing at a high and steady
rate for decades. Managers are constantly struggling to
maximize capacity and minimize transmission costs.
As businesses rely more and more on information technology,
the range of services expands. This increases the demand for
high-capacity networking and transmission facilities. Growth in
services and growth in traffic capacity go hand in hand.
Finally, trends in technology enable the provision of increasing
traffic capacity and the support of a wide range of services. The
following trends are particularly notable:
The trend toward faster and cheaper, both in computers and
communications, continues;
Both voice oriented telecommunication networks and data

14. networks are more intelligent than ever;
The Internet, the Web, and associated applications have
emerged as dominant features of both the business and personal
world; and
There has been a trend toward ever increasing mobility for
decades, liberating workers from the confines of the physical
enterprise.
Next slide.
Data Communications and Networking, continuedBusiness
DriversIP TelephonyMultimedia messagesE-businessCustomer
relationship
managementConvergenceApplicationsServicesManagementInfra
structure
*
The nature of the enterprise networking and communications
facility depends on the business applications it must support.
The following are the four main application areas that will serve
as the drivers in determining the design and makeup of the
enterprise network:
IP Telephony,
Multimedia messages,
E-business, and
Customer relationship management.
Convergence refers to the merger of previously distinct
telephony and information technologies and markets. We can
think of this convergence in terms of a four-layer model of

15. enterprise communications.
Applications are seen by the end users of a business.
Convergence integrates communications applications with
business applications.
At the services level, the manager deals with the information
network in terms of services it supplies to support applications.
The network manager needs design, maintenance, and support
services related to the deployment of convergence-based
facilities.
At the management level, network managers deal with the
enterprise network as a function providing system.
The key aspect of convergence at the infrastructure level is the
ability to carry voice over data networks, such as the Internet.
Next slide.
The Nature of Information RequirementsVoice
CommunicationsPhoneData CommunicationsTextNumerical
dataImage CommunicationsFaxCDPresentationsVideo
CommunicationsTeleconferencing
*
A business survives and thrives on information: information
within the organization and information exchanged with
suppliers, customers, and regulators.
In this course, the term voice communications primarily refers
to telephone-related communications, which is by far the most
common form of communication in any organization.

16. The term data communications is sometimes used to refer to
virtually any form of information transfer other than voice. It is
sometimes important to limit this term to information in the
form of text or numerical data.
Image communications is now an important component of the
office environment. All sorts of images, including engineering
and design specifications, mixed documents, presentation
materials, and so on, can be moved quickly around the office or
displayed on user workstations.
Video communications is also becoming important in the office
environment. With the availability of high-capacity
transmission links and networks, it has an increasing business
application, most notably videoconferencing.
All of these forms of information communication play a key
role in today’s businesses. The manager responsible for them
must understand the technology sufficiently to be able to deal
effectively with vendors of communications products and
services to make cost-effective choices among the growing
array of options.
Next slide.
Distributed ApplicationsDistributed Data ProcessingComputers
and terminalsLinked by networksThe Internet and Distributed
ApplicationsApplication softwareUnderlying interconnection
softwareClient/serverThe InternetTCP/IPDistributed
applications
*

17. The steady drop over many years in the cost of data processing
equipment, coupled with an increase in the capability of such
equipment, has led to the introduction of many small and
medium-sized computers into the business environment. Today,
it is common to find a distributed data processing configuration,
one that consists of a number of computers and terminals linked
together by networks.
A business needs to be concerned with two dimensions of
computer communications software:
The application software that is provided for a community of
terminals and computers, and
The underlying interconnection software that allows these
terminals and computers to work together cooperatively.
The mere existence of a large population of computers and
terminals creates the demand that these devices work together.
The key to the success of these applications is that all the
terminals and computers in the community speak the same
language. This is the role of the underlying interconnection
software.
Modern applications have evolved away from large, general
purpose mainframe computers to distributed computing. This
approach, called client/server architecture, requires
sophisticated, reliable, and secure data communications, but its
inherent flexibility and responsiveness make it an essential tool
in the businessperson’s information systems repertoire.
Virtually no business can compete without exploiting the
Internet and the Web. Internet technology enables secure
communication both within an enterprise and with customers,
suppliers, and partners.

18. One of the most difficult problems that has traditionally faced
computer users is that different vendors have used different and
incompatible architectures. Transmission Control
Protocol/Internet Protocol, or TCP/IP, is now universally used
for the communications software functions across multiple
vendor equipment and is the basis for the operation of the
Internet.
Distributed information processing is also essential in virtually
all businesses.
Next slide.
NetworksNetworksOverviewDemand for connectivityNeed for
communications softwareNeed for networksLANLocal area
networkFound in virtually all office
buildingsIntegrationWANLarge geographical areaCommon
carriersDifferences between LANs and WANs
*
The pressure from users for ways to communicate among
computers worldwide is irresistible. This demand for
connectivity is manifested in two specific requirements: the
need for communications software and the need for networks.
One type of network that has become increasingly common is
the local area network, or LAN. The LAN is to be found in
virtually all medium- and large-size office buildings.
Beyond the confines of a single office building, networks for
voice, data, image, and video are equally important to business.
Advances in technology have led to greatly increased capacity
and the concept of integration. Integration means that the

19. customer equipment and networks can deal simultaneously with
voice, data, image, and even video.
Wide area networks, or WANs, generally cover a large
geographical area, require the crossing of public right-of-ways,
and rely at least in part on circuits provided by a common
carrier.
There are several key distinctions between LANs and WANs:
The scope of the LAN is small, typically a single building or a
cluster of buildings. This difference in scope leads to different
technical solutions.
It is usually the case that the LAN is owned by the same
organization that owns the attached devices. For WANs, this is
less often the case.
And finally, the internal data rates of LANs are typically much
greater than those of WANs.
Next slide.
Networks, continuedCircuit Switching Dedicated
pathTelephone systemPacket SwitchingSequences called
packetsComputer to computer communicationsFrame
RelayReduced overheadATMEvolution of packet and circuit
switchingWireless NetworkingMetropolitan Area Networks
*
Traditionally, WANs have been implemented using one of two
technologies:

20. Circuit switching, and
Packet switching.
In a circuit-switching network, a dedicated communication path
is established between two stations through the nodes of the
network. That path is a connected sequence of physical links
between nodes. The most common example of circuit switching
is the telephone network.
In a packet-switching network, data are sent out in a sequence
of small chunks, called packets. Each packet is passed through
the network from node to node along some path leading from
source to destination. Packet-switching networks are commonly
used for terminal-to-computer and computer-to-computer
communications.
Packet-switching was developed at a time when digital long-
distance transmission facilities exhibited a relatively high error
rate compare to today’s facilities. As a result, there is a
considerable amount of overhead built into packet-switching
schemes. With modern high-speed telecommunications systems,
this overhead is unnecessary. Frame relay was developed to take
advantage of high data rates and low error rates. Frame relay
networks are designed to operate efficiently at user data rates of
about two-megabytes per-second.
Asynchronous transfer mode, or ATM, is a culmination of
developments in circuit switching and packet switching. ATM
can be viewed as an evolution of frame relay. ATM uses a fixed
packet length, which reduces overhead even further. ATM can
also be viewed as an evolution from circuit switching. ATM
allows the definition of multiple virtual channels with data rates
that are dynamically defined at the time the virtual channel is
created.
Wireless LANs are common and are widely used in business

21. environments. Wireless technology is also common for both
wide area voice and data networks. Wireless networks provide
advantages in the areas of mobility and ease of installation and
configuration.
A metropolitan area network, or MAN, occupies the middle
ground between LANs and WANs. The primary market for
MANs is the customer that has high speed needs in a
metropolitan area. A MAN is intended to provide the required
capacity at lower cost and greater efficiency than obtaining an
equivalent service from the local telephone company.
Next slide.
The Transmission of InformationFiber
OpticCostCapacityWirelessUsing any communication
systemConnect to information servicesTransmission and
Transmission MediaTwisted pair linesCoaxial cableOptical fiber
cableTerrestrial and satellite microwaveTransmission Efficiency
*
The basic building block of any communications facility is the
transmission line. There are certain aspects of transmission
technology that a manager must understand to be able to ask the
right questions and make informed decisions. Of particular note
are fiber optic transmission and wireless transmission.
The ever-increasing capacity of fiber-optic channels is making
channel capacity a virtually free resource. Because of its high
capacity and because of its security characteristics, it is
becoming increasingly used within office buildings to carry the
growing load of business information.

22. The second medium—wireless transmission—is a result of the
trend toward universal personal telecommunications and
universal access to communication. The first concept refers to
the ability of a person to identify him or herself easily and to
use conveniently any communication system in a large area in
terms of a single account. The second refers to the capability of
using one’s terminals in a wide variety of environments to
connect to information services.
Despite the growth in the capacity and the drop in the cost of
transmission facilities, transmission services remain the most
costly components of a communications budget for most
businesses. Thus, the manager needs to be aware of techniques
that increase the efficiency and use of these facilities. The two
major approaches to greater efficiency are multiplexing and
compression.
Multiplexing refers to the ability of a number of devices to
share a transmission facility.
Compression involves squeezing the data down so that a lower-
capacity, cheaper transmission facility can be used to meet a
given demand.
Information can be communicated by converting it into an
electromagnetic signal over some medium, such as a twisted-
pair telephone line.
The most commonly used transmission media are:
Twisted pair lines,
Coaxial cable,
Optical fiber cable, and
Terrestrial and satellite microwave.
A major cost in any computer/communications facility is

23. transmission cost. Because of this, it is important to maximize
the amount of information that can be carried over a given
resource or, alternatively, to minimize the transmission capacity
needed to satisfy a given information communications
requirement. The standard technique for achieving this
objective is multiplexing.
Next slide.
Management IssuesNetwork SecurityUnique Management
IssuesPee-to-peer interconnectionsComplexity of managing
systemsCriticality of systemsCostsFinding skilled personnel
*
As companies rely increasingly on networks and as access by
outsiders via the Internet and other links grows, the vexing
question of security becomes ever more important. Companies
are at risk for the disclosure of confidential information and for
the unauthorized altering of corporate data.
Like any resource, information technology has to be managed.
Many of the management functions required are common to
other aspects of business management, but the following
requirements are special to information technology:
Networks have evolved from an easily controlled centralized
approach into peer-to-peer interconnection among highly
distributed systems.
Peer-to-peer networks have grown larger and larger so that
managing, monitoring, and maintaining them has become very
complex.

24. In many business sectors, network computing devices constitute
a critical strategic resource than cannot be allowed to fail.
Communications costs are climbing, and there is a shortage of
skilled personnel to staff network command centers.
Next slide.
SummaryInformation and communicationData communications
and networkingConvergence and unified communicationsThe
nature of business information requirementsDistributed
applicationsNetworksThe transmission of information;
Management issuesStandards
*
We have now reached the end of this lesson. Let’s take a look at
what we’ve covered.
We started the lesson by discussing that effective and efficient
data communication and networking facilities are vital to any
enterprise. Three different forces have consistently driven the
architecture and evolution of data communication and
networking facilities:
Traffic growth,
Development of new services, and
Advances in technology.
Next we examined that a business survives and thrives on
information: information within the organization and
information exchanged with suppliers, customers, and
regulators.

25. Then we saw that the pressure from users for ways to
communicate among computers worldwide is irresistible. This
demand for connectivity is manifested in two specific
requirements: the need for communications software and the
need for networks.
Next we discovered that the basic building block of any
communications facility is the transmission line. There are
certain aspects of transmission technology that a manager must
understand to be able to ask the right questions and make
informed decisions. Of particular note are fiber optic
transmission and wireless transmission.
Lastly, we concluded the lecture by examining how as
companies rely increasingly on networks and as access by
outsiders via the Internet and other links grows, the vexing
question of security becomes ever more important. Companies
are at risk for the disclosure of confidential information and for
the unauthorized altering of corporate data.
This completes this lesson.
Please respond to the following:
After completing your reading and assignments this week, what
do you think about the trends in communication and
networking? How have you seen it impact business or do you
think it will impact business? Do you think the burden on
managers is greater or lesser when it comes to technology
skills? Why do you think that?