1. Information Technology in Business: Telecommunications, Networks and Internet Basics

2. MIS 2212 Learning Objectives When you finish this chapter, you will: –Recognize why successful managers must be familiar with telecommunications concepts and terminology. –Know the principles of communication within a computer system and among computers. –Be able to identify the major media and devices that are used in telecommunications.

3. MIS 2213 Learning Objectives –Be able to list and explain the functions of different network layouts and the concept of protocols. –Understand how telecommunications can improve operations in organizations. –Know the latest developments in telecommunications media and transmission speeds. –Understand the historical development of the Internet –Understand the main structural components of the Internet –Understand how HTML, HTTP, browsers and servers work together to form the WWW

4. MIS 2214 Telecommunications in Business Telecommunications –Any form of long distance communication, including telephone, television and radio Telecommunications has improved business in three main ways: –Better communication –Higher efficiency –Better distribution of data

5. MIS 2215 What is Data Communications? Data Communications –Any transfer of data within a computer, between a computer and another device, or between two computers Integration –Business are increasingly integrated in their use of computers, telephony, video and data networks

6. MIS 2216 What is a Telecommunications System? Compatible hardware and software used to communicate information from one place to another –Will include voice, text, graphics, documents and video

7. MIS 2217 A Generalized Telecommunications System Hardware (Host computer, front end communication processor, modem, multiplexor) Communications media (Cable or wireless) Communications software Data communications providers Communications protocols Communications applications (EDI, videoconferencing, EFT, etc.)

8. MIS 2218 Electronic Signals Analog –Information imbedded in the changing characteristics of the wave Amplitude or frequency based Digital –Information imbedded as 1 or 0, on or off

9. MIS 2219 Modulation Figure 6.8 Signal modulation

10. MIS 22110 Modulation Amplitude Modulation (AM) Frequency Modulation (FM) Phase Modulation

11. MIS 22111 Multiplexing Figure 6.9 Multiplexing

12. MIS 22112 Communications Devices Modems –Devices that modulate and demodulate signals, converting from analog to digital and digital to analog Multiplexers –Devices that allow several telephones or computers to transmit data through a single line Frequency-division multiplexing Time-division multiplexing Front End Processors

13. MIS 22113 Channels and Media Communication Channel –Physical medium through which data can be communicated. Channel Capacity –Narrow band –Broadband

14. MIS 22114 Channels and Media Media –A medium is any means by which data can be transmitted. Transmission speed –A medium’s capacity is determined by the range of bits per second at which it can operate. Baud Repeater

15. MIS 22115 Channels and Media Twisted Pair –Telephone line made of a pair of copper wires twisted to reduce electromagnetic interference (EMI) Coaxial Cable –Commonly used for cable television transmission More expensive than twisted pair Greater transmission rate than twisted pair Much less susceptible to EMI

16. MIS 22116 Channels and Media Microwaves –High-frequency, short radio-frequency (RF) waves Terrestrial microwave Satellite microwave Optical Fiber –Fiber-optic technology uses light instead of electricity to transmit data. Cellular and Wireless –Radio frequency technologies –Fixed or mobile

17. MIS 22117 Channels and Media Figure 6.5 Transmission speed measurement unit

18. MIS 22118 Channels and Media Figure 6.6 Telecommunications transmission speeds of different media

19. MIS 22119 Channels and Media Figure 6.7 Characteristics of channel media

20. MIS 22120 A Variety of Services Figure 6.15 Services offered by telecommunications firms

21. MIS 22121 What is Data Communications? Figure 6.1 Parallel and serial transmission

22. MIS 22122 Communication Direction Three Modes of Communication Between Devices –Simplex One direction only –Half-Duplex Both directions, but only one at a time –Full-Duplex Simultaneous in both directions

23. MIS 22123 Communication Direction Figure 6.2 Simplex, half-duplex, and full-duplex communication

24. MIS 22124 Communication Direction Asynchronous Communication –In asynchronous transmission, the devices are not synchronized by any timing aids. –Advantage Does not need sophisticated and expensive timing hardware –Disadvantage Overhead, time spent transmitting bits that are not a part of the primary data

25. MIS 22125 Communication Modes Figure 6.3 The character D transmitted in asynchronous mode

26. MIS 22126 Communication Modes Synchronous Communication –In synchronous communication, data are transmitted using timing devices. –Messages are transmitted in packets. –Advantage of synchronous communication Overhead in synchronous communication is significantly smaller than in asynchronous communication.

27. MIS 22127 Communication Modes Figure 6.4 Synchronous transmission

28. MIS 22128 Protocols Definition –Rules and procedures governing transmission across a network Line access Collision avoidance TCP/IP –Standard protocol of the Internet and intranets –Transmission Control Protocol/Internet Protocol –Designed for sending large files across unreliable networks –Utilizes packets of information

29. MIS 22129 OSI Standard Seven Layer Model –Governs peer-to-peer communication between software at each layer –From physical layer (how bits are transmitted over a channel) –To application layer (file transfer, security, etc)

30. MIS 22130 Open Systems Interconnect Model Figure 6.14 The seven layers of the OSI model

31. MIS 22131 Networks LANs (Local Area Networks) –Networks within a building, or within a group of adjacent buildings WANs (Wide Area Networks) –Networks across significant distances, either within a single organization or spanning multiple organizations Value-added networks (VANs) Wireless communication

32. MIS 22132 Network Topology Figure 6.12 Network topologies

33. MIS 22133 Networks Devices Bridge –Connects two networks at the data link layer Router –Connects two networks at network layer –Provides intelligent routing, some network management functions and security Gateways –Connect networks using different protocols Switches –Incorporate features of bridges and gateways

34. MIS 22134 Other Standards (or lack thereof) Operating Systems –No standard exists Graphical User Interface –X Windows Software Applications –No standard for programming language, DBMS, etc.

35. MIS 22135 Client/Server Computing Enabled by proliferation of powerful desktop computers and decentralized servers Principle –Processing functions divided between to separate, distinct computers –One requests services of a server (the client) –One delivers a service upon request (the server)

36. MIS 22136 Example of Client/Server Computing Email –Email client (Outlook) sends request to POP server for messages –POP Server receives and validates request to download email –Client processes data received (formats, displays, stores messages)

37. MIS 22137 Example of Client/Server Computing Database Transaction –Client program running on PC sends query to DBMS running on central server –DBMS on server parses and executes the query –DBMS assembles resulting data (or status result) and sends it to client –Client receives data and processes it (displays it, sends message to user, etc)

38. MIS 22138 Benefits of Client/Server Computing Potential to reduce cost –By offloading computing cycles to cheaper and underutilized desktop PC Improved performance –Has enabled high-performing graphical user interfaces