Chap006 MIS (Management Information System)
•Download as PPT, PDF•
0 likes•320 views
MIS (Management Information System)
Recommended
Recommended
More Related Content
Viewers also liked
Viewers also liked (10)
Similar to Chap006 MIS (Management Information System)
Similar to Chap006 MIS (Management Information System) (20)
More from Abbott
Recently uploaded
Recently uploaded (20)
Chap006 MIS (Management Information System)
- 1. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 1 I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien C h a p t e r 6 Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. Telecommunications and Networks
- 2. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 2 Chapter Objectives • Identify several major developments and trends in the industries, technologies, and applications of telecommunications and networks. • Identify the basic components, functions, and types of telecommunications networks. • Explain the functions of major types of telecommunications network hardware and media.
- 3. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 3 Trends in Telecommunications More electronic commerce, enterprise collaboration, online business operations and strategic advantage in markets More vendors, carriers, alliances, and network services, accelerated by deregulation & Internet growth Extensive Internet, interconnected local & global digital networks, improved transmission channels Industry Trends Technology Trends Application Trends
- 4. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 4 Telecommunications Strategic Capabilities Overcome Geographic Barriers: Capture information about business transactions from remote locations. Overcome Geographic Barriers: Capture information about business transactions from remote locations. Overcome Time Barriers: Provide information to remote locations immediately after it is requested. Overcome Time Barriers: Provide information to remote locations immediately after it is requested. Overcome Cost Barriers: Reduce the cost of more traditional means of communications. Overcome Cost Barriers: Reduce the cost of more traditional means of communications. Overcome Structural Barriers: Support linkages for competitive advantage. Overcome Structural Barriers: Support linkages for competitive advantage.
- 5. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 5 Internet Applications E-mail Internet Relay Chat Telnet Search Engines E-Commerce File Transfer Protocol (FTP) Popular Uses of the Internet Popular Uses of the Internet
- 6. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 6 Basic Components in a Telecommunications Network Telecommunications Software Telecommunications Software 1 2 3 4 52 PCs, NCs, and Other Terminals Computers Telecommunications Channels and Media Telecommunications Processors
- 7. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 7 Wide Area Networks
- 8. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 8 Local Area Networks Network Server Network Server Shared Database and Software Packages Shared Printer PCPC PC PC PC Internetwork Processor to Other Networks
- 9. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 9 Other E-Business Networks Router Intranet Server Host System Intranet Server The Internet Fire wall Fire wall Router Extranet
- 10. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 10 Client/Server Networks and Network Computing Network Server Network Server Host System Superserver Host System Superserver Client User Interface Application Processing Application Control Distributed Database Central database control Heavy duty processing ServerServer ServerServer NetPC Browser-based User Interface Web OS Application Software Application DBMS DB
- 11. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 11 Telecommunications Communication Media • Twisted Pair • Coaxial Cable • Fiber Optics • Terrestrial Microwave • Communication Satellites • Cellular Technologies • Wireless LAN
- 12. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 12 Telecommunications Processors and Software • Modems • Multiplexers • Internetwork Processors – Switches – Routers – Hubs – Gateways • Fire walls • Network Operating System • Telecommunications Monitor • Middleware • Network Management Software
- 13. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 13 Network Topologies
- 14. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 14 Network Protocols: The OSI Architecture Application LayerApplication Layer Presentation LayerPresentation Layer Session LayerSession Layer Transport LayerTransport Layer Network LayerNetwork Layer Data Link LayerData Link Layer Physical LayerPhysical Layer Seven Layers of the OSI Communications Architecture
- 15. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 15 The Internet’s TCP/IP Application or Process Layer Internet Protocol (IP) Host-to-Host Transport Layer Network Interface Physical Layer Application Layer Presentation Layer Session Layer Transport Layer Network Layer Data Link Layer Physical Layer OSIModel
- 16. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 16 Chapter Summary • Organizations are becoming internetworked enterprises that use the Internet, intranets, and other telecommunications networks to support E- Business. • Telecommunications has entered a deregulated and fiercely competitive environment with many vendors, carriers, and services • A major trend is towards pervasive use of the Internet and its technologies to build interconnected enterprise and global networks.
- 17. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 17 Chapter Summary (cont) • The major components of any telecommunications network are: – Terminals, – Telecommunications processors, – Communication channels, – Computers, and – Telecommunications software. • There are several basic types of telecomm networks, including wide area networks (WANs) and local area networks (LANs).
- 18. Irwin/McGraw-Hill Copyright © 2001, The McGraw-Hill Companies, Inc. All rights reserved. I n t r o d u c t i o n t o I n f o r m a t i o n S y s t e m s Tenth EditionJames A. O’Brien 18 Chapter Summary (cont) • Key telecommunications network alternatives include telecommunications media, processors, software, channels, and architectures.
Editor's Notes
- Telecommunications networks are a vital part of today’s E-Business. Telecommunications is the exchange of information in any form from one place to another using electronic or light-emitting media, over computer-based networks. Major trends occurring in the field of telecommunications have a significant impact on management decisions in this area. Key trends include: Industry Trends. The key trend in this area is a move away from a few, large, regulated monopolies as suppliers toward an industry structure with many suppliers in fierce competition for new customers with new products and innovative services. Bottom line: Greater number of competitive vendors, carriers, alliances, and network services, accelerated by deregulation and the growth of the Internet. The service and vendor options available to meet a company's telecommunications needs have increased dramatically. Technology Trends. Toward extensive use of Internet, digital fiber optics, and wireless technologies to create high-speed interconnected local and global digital networks, to support multimedia transmission. Another major technology trend is the advent of open systems -- information systems that use common standards for hardware, software, applications, and networking, which support greater connectivity and network interoperability. Application Trends. Technology and industry trends are towards the pervasive use of the Internet and enterprise intranets and interorganizational extranets to support electronic commerce, enterprise collaboration, online business operations and strategic advantage in local and global markets. Trends towards opening up application development to more providers, more products, and more choices for businesses and end users.
- Information technology, especially in telecommunications-based applications, helps a company overcome geographic, time, cost, and structural barriers to business success. As shown in the slide there are four strategic capabilities of telecommunications and other information technologies. This figure emphasizes how several applications of electronic commerce can help a firm capture and provide information quickly to end users at remote geographic locations at reduced costs, as well as supporting its strategic organizational objectives. For example, traveling salespeople and those at regional sales offices can use the Internet, extranets, and other networks to transmit customer orders from their laptop or desktop PCs, thus breaking geographic barriers. Point-of-sale terminals and an online sales transaction-processing network can break time barriers by supporting immediate credit authorization and sales processing. Teleconferencing can be used to overcome cost barriers by reducing the need for expensive business trips since it allows customers, suppliers, and employees to participate in meetings and collaborate on joint projects. Finally, electronic data interchange systems are used by the business to overcome structural barriers by establishing strategic relationships with their customers and suppliers by making the exchange of electronic business documents fast, convenient, and tailored to the needs of the business partners involved.
- The Internet is the largest "network of networks" and the closest model of the information superhighway to come. The Internet is accessible to anyone with a modem and the proper communications software on their computer. Nature of the Internet. The Internet developed from a US Defense Department network called ARPANET, established in 1969. One of the extraordinary features of the Net is its decentralized nature. No one "runs" the Net; it is not controlled either from a central headquarters nor governed by a single business or government agency. Like a real highway, it is "there" maintained to some degree by those who use it. But travel on it is pretty much up to the end users themselves. Internet Applications: E-Mail. Allows users to send and receive electronic messages. Discussions Forums and Chat Rooms. Allow users worldwide to participate in special interest forums formed by newsgroups and businesses alike. Allows you to read and respond to other messages in real-time. Information Retrieval. Internet browsers like Netscape and Internet Explorer allow the user to surf the Web through hyperlinked web pages. Search Engines allow users to access software and information on thousands of databases. The file transfer protocol (FTP) allows users to download a wealth of multimedia information. Telnet. Allows users to access and use remote computer systems around the world. Business Use of the Internet. By 1995, over 1.5 million host networks on the Internet belonged to businesses. Businesses on the Internet are there in part to take advantage of the easy, worldwide communications available through E-mail and file transfer protocols (FTPs). But business is also on the Net to help shape the network as a channel for conducting business transactions -- buying and selling goods and services in cyberspace to distant customers linked by computers and modems. Business uses of the Internet are rapidly developing in areas such as electronic commerce.
- Like any communications model, a telecommunications network connects a sender to a receiver over a channel for sharing messages. The basic components of a telecommunications network are: Terminals. These are networked microcomputer workstations or video input/output stations that provide the sending and receiving endpoints for the network. Telecommunications Processors. These are specialized hardware components that support data transmission and reception between terminals and computers. Examples include modems, routers, and switches. Telecommunications Channels and Media. A channel connects two or more parties in a network. Media are the particular way a channel is connected. Telecommunications channels use combinations of media such as copper wires, coaxial cables, fiber optic cables, and microwave carriers to transmit information. Computers. All sizes and types of computers can and are connected to telecommunications networks. Typical arrangements include using a mainframe as a host for the network, a minicomputer as a front-end processor, with a dedicated microcomputer as a network server to a smaller local group of networked microcomputer workstations. Telecommunications Control Software. Consists of programs that control telecommunications activities and manage the functions of telecommunications networks. Examples include network operating systems, browsers and telecommunications monitors.
- Telecommunications networks covering a large geographic area are called wide area networks (WANs). Networks that cover a large city or metropolitan area (metropolitan area networks or MANs) can also be included in this category. Such large networks have become a necessity for carrying out the day-to-day activities of many business and government organizations and their end users. For example: WANs are used by many multinational companies to transmit and receive information among their employees, customers, suppliers, and other organizations across cities, regions, countries, and the world.
- Local Area Networks (LANs) connect computers and other information processing devices within a limited physical area, such as an office, a building, or work site. LANs use a variety of telecommunications media. Key concepts and components of LANs include: Telecommunications Media. Includes twisted-pair wire, coaxial cable, fiber optics, terrestrial microwave, communications satellites, cellular radio, and wireless radio systems. Network Interface Card. PCs on a network must have a circuit board installed to handle the network interface. This is the typical way of expanding PC capability. Teaching Tip: The advent of Windows 95 and Plug and Play architecture makes the installation of network cards by end users much easier. Network Server. As mentioned earlier, this is a dedicated PC with a large hard disk capacity for secondary storage. Many servers also have more RAM than the individual workstations on the network. Network Operating System. Just as individual PCs have their own operating systems, the network operating system controls the interface between users and machine hardware as well as the telecommunications peripherals linking them. Internetwork Processors. Most LANs are connected via telecommunications to other networks, which might be other LANs, wide area networks (WANs), mainframes, or very large networks like the Internet. Interconnected telecommunications networks rely on internetwork processors, such as switches, routers, hubs, or gateways to make internetworking connections to other networks.
- Intranets. Are secure internal networks whose web browsing software provides easy point-and-click access to end users, enabling them to access multimedia information on internal websites. A company, its business units, departments, and workgroups may establish intranet websites on internal web servers. Security devices and software like fire walls control access to the intranet. One of the attractions of corporate intranets is that their Internet-like technology makes them more adaptable, as well as easier and cheaper to develop and use than either traditional client/server systems or mainframe legacy systems. Extranets. Are networks that link some of the intranet’s resources of a company with other organizations and individuals. For example, extranets enable customers, suppliers, subcontractors, consultants, and others to access selected intranet websites and other company databases. Organizations can establish private extranets, or use the Internet as part of the network connection between them. Virtual Private Networks (VPNs). Many organizations use VPNs to establish secure intranets and extranets. A VPN is a secure network that uses the Internet as its main backbone network, but relies on fire walls and other security features. In this manner, a company can use the Internet to establish secure intranets with remote branch offices and secure extranets between itself and business partners and customers.
- Client/Server Networks. Are the predominant information architectures used in business today. In a client/server network, the end user PC is the client. These are interconnected by local area networks, and share application processing with network servers. This is sometimes called a two-tier client/server architecture. Local area networks can also be interconnected with other networks, including host systems and superservers. Client/server architectures are seen as more economical and flexible than legacy mainframe systems. Network Computing Networks. Network computers and other thin clients provide a browser-based user interface for processing small application programs called applets. Application and database servers provide almost all the software needed by end users. This includes the operating system, application software, applets, databases, and database management systems. This architecture is sometimes called a three-tier client/server model.
- Telecommunications channels make use of a wide variety of media. Some major types of telecommunications media include: Twisted-Pair Wire. This is the traditional phone line used throughout the world. It is the most widely distributed telecommunications media but is limited in the amount of data and speed of transmission. Coaxial Cable. This is a sturdy copper or aluminum wire wrapped in spacers to insulate and protect it. Coaxial cable can carry more information and at higher speeds than twisted-pair wires. It also is a higher-quality carrier, with little interference. Fiber Optics. These are hair-thin glass filaments spun into wires and wrapped in a protective jacket. Fiber optics transmit light pulses as carriers of information and so are extremely fast and produce no electromagnetic radiation. This makes them extremely reliable channels, although splicing cables for connections is difficult. Terrestrial Microwave. Earthbound microwave radiation transmits high-speed radio signals in line-of-sight paths between relay stations.. Communications Satellites. Satellites in geosynchronous orbit are used to transmit microwave signals to any place on earth using dish antennas for sending and receiving. Cellular and PCS Systems. Low power transmitters on each cell of the system allow users to take advantage of several frequencies for communications. Newer Personal Communication Services (PCS) use digital technologies that provide greater capacity, security, and additional services like voice mail and paging. The growth in web-enabled information appliances like PDAs, smart phones, and pagers has sparked the interest in developing a wireless application protocol (WAP). This standard will allow these devices access to the Web. Wireless LANs. Using radio or infrared transmission, some LANs are completely wireless, thus eliminating the cost of installing wire in existing structures.
- Telecommunications processors perform a variety of support functions. Some common examples include: Modems. Convert digital signals coming from a computer into analog signals that can be transmitted over ordinary phone lines. A modem at the other end of the communication line converts the analog signal back to digital. Modems also support a variety of telecommunications functions, such as transmission error control, automatic dialing and answering, and faxing capabilities. Multiplexers. Are a communication processor that allows a single communication channel to carry simultaneous data transmissions from many terminals. This is accomplished in two basic ways: Frequency Division Multiplexing (FDM). Divides a high-speed channel into multiple slow-speed channels. Time Division Multiplexing (TDM). Divides the time each terminal can use the high-speed line into time slots. Statistical Time Division Multiplexing allows for dynamic allocation of time slots to active terminals only. Internetwork Processors. Are used to interconnect telecommunications networks. They include: Switches. A communication processor that makes connections between telecommunications circuits in a network so a message can reach its intended destination. Routers. A processor used to interconnect networks with different protocols. Used for routing messages to their destination. Hubs. A port switching communication processor. It enables temporary connections to be made to different devices, e.g. printers, servers, workstations etc., on the network. Thus, it allows network resources to be shared. Gateways. Allow networks with different architectures, e.g. mainframes and client/servers, to be interconnected. Fire walls. Security devices used to protect networks from intrusions by screening all network traffic. Network Operating System. Software that controls telecommunications and the use of shared resources. Example: Windows 2000 Server, Unix. Telecommunications Monitors. Computer programs that control and support the communications between computers and terminals in a network. Example: CICS. Middleware. Software that helps diverse networks communicate with each other. Network Management Software. Software that is used to monitor the performance and operations of the network and its resources.
- There are three basic topologies used in telecommunications networks: Star Topologies. Connect end user computers to a central computer. Used for centralizing processing. Since the network is reliant on the performance of the central computer, this topology is less reliable than either ring or bus. If the central computer fails, the network fails. May be used in WANs and LANs. Ring Topologies. Connect end user computers together in a ring on a more equal basis. It is more reliable and has no single point of failure. Used mostly in LANs. Bus Topologies. Connect end user computers on a common channel. Used commonly in business LANs. It also has no single point of failure. It is cheaper than ring networks, but sometimes less reliable. Mesh Networks. A variation of a ring network that uses a direct communication line to connect some or all of the computers in the ring to each other. Tree Network. A network which joins several bus networks together.
- Until quite recently, there was a lack of sufficient standards for the interfaces between the hardware, software, and communication channels of data communication networks. This resulted in incompatible network systems, and thus, increased the cost and reduced the efficiency of data communications. In response several manufacturers and international organizations developed standards called protocols and master plans called network architectures to support the development of advanced data communication networks. A protocol is a set of rules and procedures for the control of communications in a network. The International Standards Organization (ISO) has developed a seven-layer Open Systems Interconnection (OSI) model to serve as a standard model for network architecture. Application Layer. This layer provides communications services for end user applications. Presentation Layer. This layer provides appropriate data transmission formats and codes. Session Layer. This layer supports the accomplishment of telecommunications sessions. Transport Layer. This layer supports the organization and transfer of data between nodes in the network. Network Layer. This layer provides appropriate routing by establishing connections among network links. Data Link Layer. This layer supports error free organization and transmission of data in the network. Physical Layer. This layer provides physical access to the telecommunications media in the network.
- The Internet uses a system of telecommunications protocols that has become so widely used that it is equivalent to a network architecture. The Internet’s protocol suite is called Transmission Control Protocol/Internet Protocol and is known as TCP/IP. Five levels of protocols can be related to the seven layers of the OSI architecture. 1. TCP/IP Application or Process Layer is related to the Application layer, presentation layer, and session layer of the OSI communications network architecture. 2. TCP/IP Host-to-Host Transport Layer is related to the Transport Layer of the OSI communications network architecture. 3. TCP/IP Internet Protocol (IP) Layer is related to the Network Layer of the OSI communications network architecture. 4. TCP/IP Network Interface Layer is related to the Data Link Layer of the OSI communications network architecture. 5. TCP/IP Physical Layer is related to the Physical Layer of the OSI communications network architecture. TCP/IP is used by the Internet and by all intranets and extranets. Many companies and other organizations are also converting their client/server networks to TCP/IP. These are sometimes called IP Networks.