1. Module 4
Business Value of Telecommunication Networks
Two companies-no geographic boundaries
Connecting computers……………
Businesses have become Networked Enterprises
Network means an interconnected or interrelated chain, group or system
Networked Enterprises
Better business communication
Better distribution of data
Instant transactions
Flexible work force
Greater efficiency
Emergence of Digital Firm
• Digitally enabled relationships with customers, suppliers, and employees
• Core business processes accomplished using digital networks
• Seamless flow of information within the firm, and with strategic partners
2. Components of an information system
People resources-People are required for the operation of all information systems
End users- are people who use an information system or the information it produces.
IS specialists –are people who develop and operate information systems
3. System analysts-design information systems based on the information requirements of end
users.
System developers-create computer programs based on the specifications of systems analysts.
System operators-monitor and operate large computer systems and networks
Hardware resources-include all physical devices and materials used in information processing.
Machines-physical devices (computers, peripherals, telecommunications networks, etc.)
Computer system –which consist of central processing units containing microprocessors, and a
variety of interconnected peripheral devices
Computer peripherals-which are devices such as a keyboard or electronic mouse for input of
data and commands, a video screen or printer for output of information, and magnetic or
optical disks for storage of data resources.
Software resources-include all sets of information processing instructions
System software-such as an operating system program, that controls and supports the
operations of a computer system.
Application software-are programs that direct processing for a particular use of computers by
end users.
Data resources-Data constitutes a valuable organizational resource
Databases - a collection of logically related records or files. A database consolidates many
records previously stored in separate files so that a common pool of data records serves many
applications.
Knowledge Bases - which hold knowledge in a variety of forms such as facts and rules of
inference about various subjects.
Network resources-
Telecommunications networks like the Internet, intranets, and extranets have become essential
to the successful electronic business and commerce operations of all types of organizations and
their computer-based information systems . Network resources include:
Communications media (twisted-pair wire, coaxial cable, fiber-optic cable, and microwave, and
satellite wireless systems.
Network support (people, hardware, software, and data resources that directly support the
operation and use of a communications network)
TELECOMMUNICATIONS NETWORK MODEL
4. Terminals
Terminals are any input/output devices that use telecommunications networks to transmit or
receive data.
1. Video Terminals
2. Microcomputers
3. Telephones
4. Office Equipment
5. Transaction Terminals
Telecommunications Processors
Support data transmission and reception between terminals and computers.
5. They include:
1. Modems
2. Switches
3. Routers
- Convert digital to analog, control the speed ,accuracy and efficiency of the communication
flow.
Modems:
These devices are the most common type of communications processor, and are probably the
most widely used data communications hardware in business. Functions of modems include:
Convert digital computer signals to analog signals for transmission over telephone lines, then
to receive these signals and convert them back to digital signals. This process is known as
modulation and demodulation. The word "modem" is a contraction of modulate and
demodulate.
Switch - is a communications processor that makes connections between telecommunications
circuits in a network so a telecommunications message can reach its intended destination.
Router - is a communications processor that interconnects networks based on different rules
or protocols, so a telecommunications message can be routed to its destination.
Hub - is a post switching communications processor. This allows for the sharing of the
network resources such as servers, LAN workstations, printers, etc.
Telecommunications Channels
• Telecommunications channels are the part of a telecommunications network that connects
the message source with the message receiver.
• They include the physical equipment used to connect one location to another for the purpose
of transmitting and receiving information.
• Data are transmitted and received over channels, which use a variety of telecommunications
media. Media include:
1. Twisted-pair Wire
2. Coaxial Cables
3. Fiber Optic Cables
4. Microwave Systems
6. 5. Communications Satellites
Twisted-Pair Wire
Twisted-pair is ordinary telephone wire, consisting of
copper wire twisted into pairs (twisted pair wire).
Most widely used media for telecommunications.
Used in established communications throughout the world.
Used for both voice and data transmissions.
Used extensively in home and office telephone systems and many LANs and WANs.
Disadvantages:
Susceptible to a variety of types of electrical interference (noise), which limits the practical
distances
Signals must be “refreshed” every one to two miles through the use of repeaters, which are
very expensive.
Coaxial Cable
Consists of copper or aluminium wire wrapped with spacers to insulate and protect it.
Insulation minimizes interference and distortion of the signals the cable carries.
Can carry a large volume of data - about 100 million bits per second (1800 to 3600 voice calls
at once). A 2" diameter coaxial cable can carry up to 5,500 channels.
Coaxial cables can be bundled together into a much larger cable for ease of installation.
Can be placed underground and laid on the floors of lakes and oceans.
Allows for high-speed data transmission used in high-service metropolitan areas for cable TV
systems
Used extensively in office buildings and other work sites for local area networks.
Disadvantages:
More expensive than twisted pair.
Fiber optics
7. This media consists of one or more hair-thin filaments of glass fiber wrapped in a protective
jacket. Signals are converted to light form and fired by laser in bursts.
Relatively low cost
Offers high transmission volume. A 2" diameter fiber optic cable can carry up to 50,000
channels.
Provides substantial size and weight reductions.
Provides increased speed and greater carrying capacity than coaxial cable and twisted-pair
lines.
Is not susceptible to electronic noise and so has much lower error rates than twisted-pair and
coaxial cable.
Message security of fiber optic communications is very resistant to illegal data theft; taps can
be easily detected.
TYPES OF TELECOMMUNICATIONS NETWORKS
Local Area Networks(LAN)
Metropolitan Area Networks(MAN)
Wide Area Networks(WAN)
Virtual Private Networks(VPN)
Client/server networks
Local Area Network (LAN)
8. Are telecommunications networks that connect information-processing devices within a
limited physical area. These networks cover areas such as:
· Offices
· Classrooms
· Buildings
· Manufacturing plant
Characteristics of LANs:
• LANs use a variety of telecommunications media, such as ordinary telephone wiring, coaxial
cable, or wireless radio systems to interconnect microcomputer workstations and computer
peripherals.
• To communicate over the network, a PC usually has a circuit board called a network interface
card.
• Most LANs use a powerful microcomputer with a large disk capacity as a file server or network
server that contains a network operating system program (e.g., Novell NetWare) that controls
telecommunications and the use of network resources.
• LANs allow end users in a workgroup to communicate electronically; share hardware,
software, and data resources; and pool their efforts when working on group projects.
Metropolitan Area Networks(MAN)
Links multiple LANs with in a large city
Covers a distance of 50kms
Wide Area Network (WAN)
are telecommunications networks that cover large geographic areas. These networks cover
areas such as:
· Large city or metropolitan area
· Whole country
· Many countries and continents
Ex: used by many MNCs to transmit and receive information among their stake holders
9. Virtual Private Network(VPN)
• Establish secure Intranets and extranets
• is a secure network that uses the Internet as its main backbone network, but relies on the
firewalls and other security features of the Internet and Intranet connections and those of
participating organizations
Client/Server Networks
Characteristics of a client/server network:
End user PC or NC workstations are the clients.
Clients are interconnected by local area networks and share application processing with
network servers, which also manage the networks.
• Downsizing of larger computer systems by replacing them with client/server networks. For
example, a client/server network of several interconnected local area networks may replace a
large mainframe-based network with many end user terminals.
Network Topology
is the layout pattern of interconnections of the various elements of a computer
Network topologies may be physical or logical.
Physical topology refers to the physical design of a network including the devices, location and
cable installation.
Logical topology refers to how data is actually transferred in a network
Three basic topologies used in wide area and local area telecommunications networks are the:
Star network
Ring network
Bus network
10. Advantages of the star network:
Several users can use the central unit at the same time
Easy to detect faults and to remove parts.
No disruptions to the network when connecting or removing devices.
Benefits from centralization: As the central hub is the bottleneck, increasing its capacity, or
connecting additional devices to it, increases the size of the network very easily. Centralization
also allows the inspection of traffic through the network. This facilitates analysis of the traffic
and detection of suspicious behavior.
Disadvantages of the star network:
The whole network is affected if the main unit “goes down,” and all communications stop.
Considered less reliable than a ring network, since the other computers in the star are heavily
dependent on the central host computer. If it fails, there is no backup processing and
communications capability and the local computers will be cut off from the corporate
headquarters and from each other.
Cost of cabling the central system and the points of the star together are very high.
11. Advantages:
Ring networks do not require a central computer to control activity nor does it need a file
server.
Each computer connected to the network can communicate directly with the other computers
in the network by using the common communications channels, and each computer does its
own independent applications processing.
When one computer needs data from another computer, the data is passed along the ring.
The ring network is not as susceptible to breakdowns as the star network, because when one
computer in the ring fails, it does not necessarily affect the processing or communications
capabilities of the other computers in the ring.
Performs better than a bus topology under heavy network load
Disadvantages:
One malfunctioning workstation can create problems for the entire network
Moves, adds and changes of devices can affect the network
Communication delay is directly proportional to number of nodes in the network
Bandwidth is shared on all links between devices
12. Advantages:
Easy to implement and extend.
Well-suited for temporary or small networks not requiring high speeds (quick setup), resulting
in faster networks.
less expensive than other topologies
Cost effective; only a single cable is used.
Easy identification of cable faults.
Disadvantages:
Limited cable length and number of stations.
If there is a problem with the cable, the entire network breaks down.
Performance degrades as additional computers are added or on heavy traffic (shared
bandwidth).
It works best with limited number of nodes.
Commonly has a slower data transfer rate than other topologies.
13. Internet
Definition
A network made up of millions of smaller private networks each with the ability to operate
independent of, or in harmony with, all the other millions of networks connected to the Internet
Network of network is a group of two or more networks that are,
Interconnected physically
Capable of communicating and sharing data with each other
Able to connect together as a single network
14. At the end of December, 121 million Indians will be accessing the Internet at least once a week
to check emails, chat or log on to a social network
India is adding Internet users at the rate of almost 5-7 million a month
Internet is changing the business landscape forever in favour of India. "Now startups look to
India when planning to start a business... earlier they would flock to the US,“
About 2 billion people worldwide access the Internet and 25% of them are from China. India
contributes about 6% to the world's Net population and the US 12.5%
Cheapest and fastest means to get, provide and compile information
Getting Information-World wide Web
Providing Information- Publishing, Blogging and teaching
Compiling- conduct surveys
Internet Working-
Modem- enables two computers to communicate through phone lines
Computer
Software- Communication software & client software
15. Browser software
Internet Access-
Dialing ISPs – users Modems are connected to ISPs modem
Direct connection to an ISP
Internet Addressing-
IP address is an identifier for a particular machine on a particular network
Scheme to identify computers on the internet.
IP address consists of 4 sections representing the machine, host and the network the host
belongs to.
Domain Name-
Way to identify and locate computers connected to the internet
Contains two or more components separated by periods (dots)
Last portion of the name describes the type of organization
Eg: .biz-business, .com-commercial entities etc
16. E-Learning
E-Learning is using the Internet to enable learning (eliminates time and distance barriers).
Include:
Computer-based training.
Distance learning.
Online learning.
On-demand learning.
Logs and Blogs
Online journals that link together into a large network of information sharing.
Blogs discuss topics from poetry to political opinions.
Can take on different forms:
17. Moblogging
Vlogging
Make every individual a virtual publisher.
E-Tutoring
Fluent in any subject
Tutoring experience-online tutoring
Business Use of the Internet
Collaboration among business partners
Providing customer and vendor support
Electronic commerce
18. Marketing and sales
Customer relationship management applications
Cross-functional business applications
Applications in engineering, manufacturing, human resources, and accounting
Enterprise communications and collaboration
Strategic business alliances
Substantial cost savings can arise because applications that use the Internet and Internet-
based technologies
Attracting new customers with innovative marketing and product offerings.
Retaining present customers with improved customer service and support.
Generating revenue through electronic commerce applications.
Doing Business over Internet
Evolution of E-Business
Now, the term e-business refers to business conducted over the Internet
EDI (Electronic Data Interchange) is one of the oldest forms of e-business
EDI is the direct computer to computer transfer of business information, using a
standard format.
Software programs on different systems can exchange information without human
intervention.
Quote requests, order forms, etc.
With the growth of the Internet more businesses are using it to transact business between
partners-B2B, B2C, B2E
India to be ranked 3rd largest Internet market after China and the US
19. Six major business values by doing business on WWW–
Generate new revenue from online sales.
Reduce costs through online sales and customer support.
Attract new customers via Web marketing and advertising and online sales.
Increase the loyalty of existing customers via improved Web customer service and support.
Develop new web-based markets and distribution channels for existing products.
Intranet
A network inside an organization that uses Internet technologies to provide an Internet-like
environment within the enterprise for information sharing, communications, collaboration, and the
support of business processes
The first intranet websites and home pages began to appear in organizations in 1996-1997
An intranet is protected by security measures such as passwords, encryption, and fire walls,
and thus can only be accessed by authorized users through the Internet.
A company’s intranet can also be accessed through the intranets of customers, suppliers, and
other business partners via extranet links.
20. Since intranets are Internet-like networks within organizations, they depend on all of the
information technologies that make the Internet possible
Communications and Collaboration
Intranets can significantly improve communications and collaboration within an enterprise.
Examples include:
Using an intranet browser and PC or NC workstation to send and receive E-mail, voicemail,
paging, and faxes to communicate with others within your organization, and externally
through the Internet and extranets.
intranet groupware features improves team and project collaboration with services such as
discussion groups, chat rooms, and audio and videoconferencing.
Web Publishing:
ease, attractiveness, and lower cost of publishing and accessing business information
internally via intranet websites has been one of the primary reasons for the explosive growth
in the use of intranets in business.
Examples include:
Company newsletters, technical drawings, and product catalogs can be published in a variety
of ways including Web pages, E-mail
Business Operations and Management:
Employees within the company, or external business partners can access and run such
applications using Web browsers from anywhere on the network whenever needed.
Examples include:
Many companies are developing customer applications like order processing, inventory
control, sales management, and executive information systems that can be implemented on
intranets, extranets, and the Internet.
21. Extranet
Network links that use Internet technologies to interconnect the intranet of a business with
the intranets of its customers, suppliers, or other business partners
Companies can:
Establish direct private network links between themselves, or create private secure Internet
links between them called virtual private networks.
Use the unsecured Internet as the extranet link between its intranet ,consumers and others,
but rely on encryption of sensitive data and its own firewall systems to provide adequate
security.
22. Business Value of Extranets:
The business value of extranets is derived from several factors:
The Web browser technology of extranets makes customer and supplier access of intranet
resources a lot easier and faster
Extranets enable a company to offer new kinds of interactive Web-enabled services to their
business partners. Thus, extranets are another way that a business can build and strengthen strategic
relationships with its customers and suppliers.
Extranets enable and improve collaboration by a business with its customers and other
business partners.
Extranets facilitate an online, interactive product development, marketing, and customer-
focused process that can bring better designed products to market faster.