Transcript Telecommunications and Networks

Tonga Institute of Higher Education
IT 245
Management Information Systems
Lecture 7
Telecommunications and Networks
Internetworking the Enterprise
• First Stage in the Use of IT : Standalone
Mainframe, Mini or personal Computers.
• Second Stage : Computers connected through
networks : LAN & WAN.
• Third Stage : Intranets, Extranets & Internet, i.e.
remote computers connected through
telecommunication channels.
• Hence, importance of Telecommunications.
Trends in Telecommunications
…...1 of 3
• Industry Trends : From government-regulated
monopolies to Deregulated Market. Fierce
competition. ATH shares being divested by Internet
Telephony being introduced in India from 1st April,
2002. Merger of Telecommunications companies
across continents.
Trends in Telecommunications
……2 of 3
• Technology Trends : From transmission of voice
over ISD ( analog transmission), to fax, to digital
transmission of graphics, sound, video and text
files over Internet, extranet and intranet servers.
• Digital Network Technology: Increase in speed
and volume of data transmitted.
• From copper based media to fiber-optic cables.
Also Wireless communications.
Trends in Telecommunications
……2 of 3
• Business Applications Trends: New way of doing
business : E-Business & E-commerce
• Internetworking of Enterprise. Locking in
customers & locking out competition.
• Intranet & Extranets : Closer collaboration
between business partners. Business processes
are speeded up.
• Global reach. Great customer value. Reduced
costs/leadtime/response time.
Business Value of
Telecommunications
• Overcoming the barriers:
– Geographic
– time
– Cost
– structural
Internet Revolution
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Explosive Growth.
Information Superhighway.
Democratization of Information. Free flow.
Key Platform for information, entertainment and
business applications.
• World Wide Web : Web-sites of E-business, Ecommerce,
• Newsgroups, chat rooms
Telecom Network Model
• Components :
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Terminals,
Processors,
Channels,
Computers,
– Control Software.
Types of Telecom Networks 1of 2
• WAN : Covering a large city.
• LAN : Office, class room. Limited to one building
or a limited location ( Mfg Plant).
• Intranets & Extranets : Coverage may be global.
Inter-enterprise Networks.
• Virtual Private Network(VPN) : uses Internet as
backbone network.
• Client/Server network: Pcs connected to a
server.
Types of Telecom Networks
…2 of 2
• Peer-to-Peer Networks (P2P): Connects
an employees’ PCs to a central server.
Enables automatic transfer of files from
one PC to another.
Section II
• Technical Communications Alternatives
• Objective: To understand the important
characteristics of basic components of
Telecommunications networks
Telecommunications Media
• A component that establishes physical link
between different devices in a network
• Includes cables : Twisted Pair Wire, Coaxial,
Fiber Optic.
• Terrestrial Microwave,
• Communications Satellites,
• Cellular or Mobile Phones
Wireless Technologies.. 1 of 2
• Terrestrial Microwave : transmission through
earth-bound mw system. MW antennas placed
atop buildings, towers, hills or mountain peaks.
• Communications Satellite : First appeared in
Science Fiction in 1950s. Use MW radio as a
medium. Transmit large volumes of data. But not
suitable for interactive, real-time processing.
Wireless Technologies.. 2 of 2
• Cellular/mobile Phones & Personal
Communications Service (PCS) and pagers.
• Wireless Web : PDAs, 3-G Mobile phones
connected to Web : Download or upload e-mails,
connect to corporate databases.
Telecommunications Processors
• Modem : Modulator & Demodulator : converts
analog signals into digital & vice versa. For
personal use.
• Multiplexers: Allows a single communications
channel to carry simultaneous data
transmissions from many terminals.
• Internetwork Processors : Switches, routers,
hubs & gateways : For Business Use.
Telecommunications Software
• Teleprocessing (TP) monitors : Customer
Identification Control Systems (CICS) for IBM
mainframes.
• Network Operating Systems for LAN : Novel
NetWare, Sun’s Solaris, UNIX, Linux or MS
Windows 2000 Servers.
• Middleware: Helps diverse networks
communicate with each other.
• iPlanet Portal Server
Network Topologies
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Means Network
Structures or the
way different
terminals are
arranged in a
network.
Types : Star,
Ring and Bus.
Star Less
reliable than
Ring.
Ring & Bus are
most common in
LAN
Network Protocols & Architecture
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Protocols: Standard set of rules and procedures for the control of communications
in a network.
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Network Architectures:
– (1) The Internet’s TCP/IP : Transmission Control Protocol/Internet Protocol, and
– (2) The OSI Model : Open Systems Interconnection.
Bandwidth Alternatives
• Communications speed and capacity.
• Need for more bandwidth is continuously
increasing with increasing volumes of graphic
and video data transmission.
• Narrowband : 64 kbps to 2 mbps
• Broadband : 52 mbps to several gbps
Switching Alternatives
• Packet Switching : Subdivides communications
messages into fixed or variable groups called
packets.
• Cell Switching : Breaks voice, video & other data
into fixed cells of 56 bytes. Asynchronous
Transfer Mode (ATM) is an emerging technology
in cell switching. Fast & high capacity multimedia
transmission.
Summary
• Overview of Telecommunication and Networks
– Internetworking the Enterprise
• Technical Telecommunications Alternatives
– Telecommunication Alternatives