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Chapter 6 Information Technology in Business: Telecommunications and Networks Management Information Systems, 4th Edition 1 Learning Objectives • Explain why successful managers must be familiar with telecommunications concepts and terminology • Describe the principles of communication within a computer system and among computers • Identify the major media and devices used in telecommunications Management Information Systems, 4th Edition 2 Learning Objectives (Cont.) • List and explain the functions of different network layouts and the concept of protocols • Explain how telecommunications can improve operations in organizations • Cite the latest developments in telecommunications media and transmission speed Management Information Systems, 4th Edition 3 Telecommunications in Business • Transmittal of data from one computer to another over a distance • Telecommunications has improved business in three main ways: – Better communication – Higher efficiency – Better distribution of data Management Information Systems, 4th Edition 4 Telecommunications in Daily Use • Cellular Phones • Videoconferences • Voice Mail • Facsimile • Information Kiosks • Pay at the Pump Management Information Systems, 4th Edition 5 Telecommunications in Daily Use (Cont.) • Easy Passing • Web-Based Electronic Commerce • Worldwide Peer-to-Peer File Sharing – Napster, Gnutella, BearShare, Morpheus – With directory – Without directory Management Information Systems, 4th Edition 6 Telecommunications in Daily Use (Cont.) Management Information Systems, 4th Edition 7 Data Communications • Any transfer of data within a computer, between a computer and another device, or between two computers • Parallel and Serial Data Communications Management Information Systems, 4th Edition 8 Data Communications (Cont.) Management Information Systems, 4th Edition 9 Communication Direction • Simplex – One-way in one direction • Half-Duplex – One-way in two directions • Full-Duplex – Two-way in two directions Management Information Systems, 4th Edition 10 Communication Direction (Cont.) Management Information Systems, 4th Edition 11 Error Detection • Parity Check – Error detection method – Checks that no bits are added or deleted during transmission – Odd Parity Check looks for an odd number of ones – Even Parity Check looks for even number of ones Management Information Systems, 4th Edition 12 Bandwidth and Media • Communications medium – Physical medium through which data can be communicated – Telephone lines, television cables • Capacity – Speed at which data are communicated – Also called the transmission rate – It is often called “bandwidth” • Bandwidth is measured in bits per second (bps) – The greater the capacity, the faster the transmission Management Information Systems, 4th Edition 13 Bandwidth and Media (Cont.) Management Information Systems, 4th Edition 14 Bandwidth and Media (Cont.) • Bandwidth – Narrowband is low speed – Broadband has greater capacity • Media – A medium is any means by which data can be transmitted Management Information Systems, 4th Edition 15 Transmission speed • A medium’s capacity is determined by the range of bits per second at which it can operate • Baud is the number of signals per minute • Repeater receives and strengthens signals before sending them on Management Information Systems, 4th Edition 16 Transmission Speed (Cont.) Management Information Systems, 4th Edition 17 Twisted Pair • Telephone line made of a pair of copper wires twisted to reduce electromagnetic interference (EMI) Management Information Systems, 4th Edition 18 Coaxial Cable • Commonly used for cable television transmission – More expensive than twisted pair – Greater transmission rate than twisted pair – Much less susceptible to EMI Management Information Systems, 4th Edition 19 Microwaves • High-frequency, short radio-frequency (RF) waves – Terrestrial microwave – Satellite microwave Management Information Systems, 4th Edition 20 Optical Fiber • Fiber-optic technology uses light instead of electricity to transmit data Management Information Systems, 4th Edition 21 Characteristics of Media Management Information Systems, 4th Edition 22 Modulation • Modification of a digital signal into an analog signal • Demodulation – Modification of an analog signal into a digital signal Management Information Systems, 4th Edition 23 Modulation (Cont.) • Analog vs. Digital – Analog: A continuous series of waves – Digital: A series of discrete bits Management Information Systems, 4th Edition 24 Modulation (Cont.) Management Information Systems, 4th Edition 25 Modulation (Cont.) • Amplitude Modulation (AM) • Frequency Modulation (FM) • Phase Modulation • Modems – Devices that modulate and demodulate signals Management Information Systems, 4th Edition 26 Modulation (Cont.) Figure 6.9 Multiplexing Management Information Systems, 4th Edition 27 Networks • LANs (Local Area Networks) – Networks within a building, or within a group of adjacent buildings • WANs (Wide Area Networks) – Networks that cross organizational boundaries or reach outside the company • Value-added networks (VANs) • Wireless communication Management Information Systems, 4th Edition 28 Network Topology • Physical layout of the nodes in a network – Star – Ring – Bus – Tree Management Information Systems, 4th Edition 29 Network Topology Management Information Systems, 4th Edition 30 Networking Hardware • Network Interface Card • Hub • Switch • Bridge • Router Management Information Systems, 4th Edition 31 Virtual Private Network • A combination of private and public lines • A link between a private network and the Internet • “Virtual” refers to the illusion that the use is accessing a private network directly Management Information Systems, 4th Edition 32 Protocols • Communication protocols – Rules governing the communication between computers or between computers and other computer-related devices • Network protocols – Rules governing a network of devices Management Information Systems, 4th Edition 33 Protocols (Cont.) • LAN Protocols – Polling – Contention – Token passing • WAN Protocols – OSI (Open Systems Interconnection) • Standard protocol model • Seven layers Management Information Systems, 4th Edition 34 Protocols (Cont.) Management Information Systems, 4th Edition 35 Switching Techniques • Circuit Switching – Message is communicated in its entirety from the transmitting computer to the receiving computer • Packet Switching – Message is divided into packets of bytes and transmitted via several nodes – TCP/IP Management Information Systems, 4th Edition 36 Switching Techniques (Cont.) Management Information Systems, 4th Edition 37 The Changing Business Environment • Cellular Phones • Teleconferencing • Voice Mail • Facsimile Management Information Systems, 4th Edition 38 A Variety of Services • Cable • Digital Subscriber Line (DSL) • T1 and T3 Lines • Satellite • Fixed Wireless • Gigabit Ethernet • Optical Carrier Management Information Systems, 4th Edition 39 A Variety of Services (Cont.) Management Information Systems, 4th Edition 40 A Wireless Revolution • Popular Wireless Technologies • Would You Like Wi-Fi With That? • Combining Technologies Management Information Systems, 4th Edition 41 Wireless Technologies (Cont.) Management Information Systems, 4th Edition 42 Wireless Technologies (Cont.) Management Information Systems, 4th Edition 43 Ethical and Societal Issues Telecommuting: Pros and Cons • Pros – Saves travel cost and time – Decreases pollution – May reduce unemployment. – Productivity higher among telecommuters Management Information Systems, 4th Edition 44 Ethical and Societal Issues Telecommuting: Pros and Cons • Cons – Employers tend to pressure telecommuters to work harder than workers in the office. – No office to foster new social ties and camaraderie. – May negatively impact some segments of the economy • Restaurants • Downtown business and industries Management Information Systems, 4th Edition 45 Summary • Telecommunications concepts and terminology • Communication within a computer system and among computers • Telecommunications media and devices • Network layouts and protocols • Telecommunications impact on operations • Telecommunications developments and speed Management Information Systems, 4th Edition 46