Management information system ralp 7e ch06

• Effective communications are essential to organizational success • Define the terms communications and telecommunications and describe the components of a telecommunications system Principles of Information Systems, Seventh Edition • An unmistakable trend of communications technology is that more people are able to send and receive all forms of information over greater distances at a faster rate • Identify broad categories of communications media and discuss the basic characteristics of specific media types • Describe how a modem works • Explain the types of telecommunications carriers today and the services they provide Principles of Information Systems, Seventh Edition • Identify the benefits associated with a telecommunications network • Define the term network topology and identify five alternatives • Discuss the different communications protocols and devices used for telecommunications • Name three distributed processing alternatives and discuss their basic features • List some telecommunications applications that organizations are benefiting from today Principles of Information Systems, Seventh Edition An Overview Of Communications Systems • Communications: the transmission of a signal by way of a medium from a sender to a receiver • Signal contains a message composed of data and information • In telecommunications, sender transmits a signal through a transmission medium such as a cable Principles of Information Systems, Seventh Edition Figure 6.2: Communications and Telecommunications Principles of Information Systems, Seventh Edition An Overview Of Communications Systems (continued) • Communications can be synchronous or asynchronous • Synchronous communications: the receiver gets the message instantaneously • Asynchronous communications: the receiver gets the message some period of time after it is sent Principles of Information Systems, Seventh Edition Telecommunications • Telecommunications: electronic transmission of signals for communications, via telephone, radio, television, etc • Data communications: subset of telecommunications that refers to the electronic collection, processing, and distribution of data, typically between computer system hardware devices • Telecommunications medium: anything that carries an electronic signal and interfaces between a sending device and a receiving device Principles of Information Systems, Seventh Edition Figure 6.3: Elements of a Telecommunications System Principles of Information Systems, Seventh Edition Communications Channels: Basic Communications Channel Characteristics • Communication channels can be classified as simplex, half-duplex, or full-duplex • Simplex channel: can transmit data in only one direction • Half-duplex channel: can transmit data in either direction, but not simultaneously • Full-duplex channel: permits data transmission in both directions at the same time Principles of Information Systems, Seventh Edition 10 Figure 6.18: Client/Server Connection Principles of Information Systems, Seventh Edition 35 Interconnecting Networks: Communications Protocols • Open Systems Interconnection (OSI) model • Transmission Control Protocol/Internet Protocol (TCP/IP) • Systems Network Architecture (SNA) • IEEE 802.3 (Ethernet) Principles of Information Systems, Seventh Edition 36 Communications Protocols (continued) • Frame Relay • Asynchronous Transfer Mode (ATM) • FireWire Principles of Information Systems, Seventh Edition 37 Wireless Communications Protocols • Bluetooth • IEEE 802.11b (Wi-Fi) • IEEE 802.11g • IEEE 802.16 (WiMax) • IEEE 802.20 (MBWA) Principles of Information Systems, Seventh Edition 38 Wireless Communications Protocols (continued) • 1G • 2G • 2.5G • 3G • Multichannel Multipoint Distribution System (MMDS) Principles of Information Systems, Seventh Edition 39 Network Switching Devices • Private branch exchange (PBX): an on-premise switching system owned or leased by a private enterprise that interconnects its telephones and provides access to the public telephone system • Bridge: a device used to connect two or more networks that use the same communications protocol • Switch: a telecommunications device that routes incoming data from any one of many ports to a specific output port that will take the data toward its intended destination Principles of Information Systems, Seventh Edition 40 Network Switching Devices (continued) • Router: a device or software in a computer that determines the next network point to which a data packet should be forwarded toward its destination • Hub: a place of convergence where data arrives from one or more directions and is forwarded out in one or more other directions • Gateway: a network point that acts as an entrance to another network Principles of Information Systems, Seventh Edition 41 Network Basics: Basic Processing Strategies • Centralized processing: all processing occurs in a single location or facility • Decentralized processing: processing devices are placed at various remote locations • Distributed processing: computers are placed at remote locations but connected to each other via a network Principles of Information Systems, Seventh Edition 42 Communications Software • Network operating system (NOS): systems software that controls the computer systems and devices on a network and allows them to communicate with each other • Network-management software: enables a manager on a networked desktop to monitor the use of individual computers and shared hardware, scan for viruses, and ensure compliance with software licenses Principles of Information Systems, Seventh Edition 43 Telecommunications Applications • Linking personal computers to mainframes and networks • Voice mail • Electronic software distribution • Electronic document distribution Principles of Information Systems, Seventh Edition 44 Telecommunications Applications (continued) • Call centers • Telecommuting • Videoconferencing • Electronic data interchange (EDI) Principles of Information Systems, Seventh Edition 45 Telecommunications Applications (continued) • Public network services • Electronic funds transfer (EFT) • Distance learning • Specialized systems and services Principles of Information Systems, Seventh Edition 46 Summary • Communications: the transmission of a signal by way of a medium from a sender to a receiver • In telecommunications, the sender transmits a signal through a transmission medium such as a cable • Transmission media types: twisted-pair wire cable, coaxial cable, fiber-optic cable, microwave, cellular, and infrared • Telecommunications carriers can be divided into local exchange carriers, competitive local exchange carriers, and long-distance carriers Principles of Information Systems, Seventh Edition 47 Summary (continued) • A computer network consists of the communications media, devices, and software needed to connect two or more computer systems and/or devices • Network types: personal area network (PAN), local area network (LAN), metropolitan area network (MAN), wide area network (WAN), and international network • Network topologies: ring, bus, hierarchical, star, and hybrid • Options for how computers on a network connect: terminal-to-host, file server, and client/server Principles of Information Systems, Seventh Edition 48 Summary (continued) • Communications protocols include the Open Systems Interconnection (OSI) model, Transmission Control Protocol/Internet Protocol (TCP/IP), IEEE 802.3 (Ethernet), etc • Network switching devices: private branch exchange (PBX), bridge, switch, router, hub, and gateway • Examples of telecommunications applications are voice mail, electronic software distribution, telecommuting, videoconferencing, electronic funds transfer, and distance learning Principles of Information Systems, Seventh Edition 49 ... Rate Interface Principles of Information Systems, Seventh Edition 25 Figure 6.12: ISDN Network Switching Principles of Information Systems, Seventh Edition 26 T-Carrier System • Introduced in the... database management, printing, communications, and program execution Principles of Information Systems, Seventh Edition 34 Figure 6.18: Client/Server Connection Principles of Information Systems,... a network Principles of Information Systems, Seventh Edition 42 Communications Software • Network operating system (NOS): systems software that controls the computer systems and devices on a