Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
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 • • • • 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 : – – – – 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 • • • • 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 • Protocols: Standard set of rules and procedures for the control of communications in a network. • 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