Information Technology in Business: Telecommunications, Networks and Internet Basics

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

2. 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. MIS 221

3. 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 MIS 221

4. 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 MIS 221

5. 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 MIS 221

6. 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 MIS 221

7. 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.) MIS 221

8. 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 MIS 221

9. Figure 6.8 Signal modulation Modulation MIS 221

10. Modulation • Amplitude Modulation (AM) • Frequency Modulation (FM) • Phase Modulation MIS 221

11. Figure 6.9 Multiplexing Multiplexing MIS 221

12. 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 MIS 221

13. Channels and Media • Communication Channel • Physical medium through which data can be communicated. • Channel Capacity • Narrow band • Broadband MIS 221

14. 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 MIS 221

15. 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 MIS 221

16. 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 MIS 221

17. Figure 6.5 Transmission speed measurement unit Channels and Media MIS 221

18. Figure 6.6 Telecommunications transmission speeds of different media Channels and Media MIS 221

19. Figure 6.7 Characteristics of channel media Channels and Media MIS 221

20. A Variety of Services Figure 6.15 Services offered by telecommunications firms MIS 221

21. Figure 6.1 Parallel and serial transmission What is Data Communications? MIS 221

22. 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 MIS 221

23. Figure 6.2 Simplex, half-duplex, and full-duplex communication Communication Direction MIS 221

24. 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 MIS 221

25. Figure 6.3 The character D transmitted in asynchronous mode Communication Modes MIS 221

26. 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. MIS 221

27. Figure 6.4 Synchronous transmission Communication Modes MIS 221

28. 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 MIS 221

29. 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) MIS 221

30. Figure 6.14 The seven layers of the OSI model Open Systems Interconnect Model MIS 221

31. 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 MIS 221

32. Figure 6.12 Network topologies Network Topology MIS 221

33. 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 MIS 221

34. Other Standards (or lack thereof) • Operating Systems • No standard exists • Graphical User Interface • X Windows • Software Applications • No standard for programming language, DBMS, etc. MIS 221

35. 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) MIS 221

36. 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) MIS 221

37. 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) MIS 221

38. 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 MIS 221