Telecommunicationsand Networks

Chapter6

McGraw-Hill/Irwin Copyright © 2011 by The McGraw-Hill Companies, Inc. All rights reserved.

6-2

• Understand the concept of a network

• Apply Metcalfe’s law in understanding the value of a network

• Identify major developments and trends in the industries, technologies, and business applications of telecommunications and Internet technologies

Learning Objectives

6-3

• Provide examples of the business value of Internet, intranet, and extranet applications

• Identify the basic components, functions, and types of telecommunications networks used in business

• Explain the functions of major components of telecommunications network hardware, software, media, and services

Learning Objectives

6-4

• Explain the concept of client/server networking

• Understand the two forms of peer-to-peer networking

• Explain the difference between digital and analog signals

Learning Objectives

6-5

Network Concepts

• Interconnected chain, group, or system

• Connections created by nodes

• Exponential growth

• Metcalf’s Law– Usefulness, or utility, of a network

• Equals the square of the number of users

• More users = more useful

6-6

RWC 1: Telepresence Is Finally Coming of Age

• Immersive video experience

• Saves travel time and expense

• Video conferencing better for one-on-one

• Allows people to think globally

6-7

Telecommunication Trends

6-8

Telecommunications-Based Services

6-9

Value of Telecommunications Networks

6-10

Business Use of the Internet

6-11

Business Value of the Internet

Summary of bulleted list

6-12

Intranets as Information Portals

6-13

Extranet Connectivity

6-14

RWC 2: Medicine through Videoconferencing

• Visual-communication workstation connected to major hospital stroke center

• Improves – Diagnostic ability– Training of new doctors– Communication with patients

• Handicapped• Second-languages

– Discussion and collaboration

6-15

Telecommunications Network Model

6-16

Network Component Alternatives

6-17

Wide Area Network (WAN)

6-18

Local Area Network (LAN)

• Connects computers in a limited physical area– Office, classroom, or building

6-19

Virtual Private Network

6-20

Client/Server Network

6-21

Network Computing

6-22

Peer-to-Peer Network Diagrams

6-23

Telecommunications Media

• Twisted-Pair Wire– Similar to telephone wire

• Coaxial Cable– Wire wrapped with insulation

• Fiber-Optic Cable– One or more hair-thin filaments of glass

6-24

• Communications Satellites– Geosynchronous orbit

– Serve as relay stations

• Wireless LANS– Wireless radio-wave technology

• Bluetooth– Short-range wireless technology

• Other Wireless Systems– Cellular phones, Mobile radio, PDAs

• Telecommunications vital and pervasive– Web-enabled e-business processes

Wireless Technologies

6-25

• Other Wireless Systems– Cellular phones

– Mobile radio

– PDAs

• Telecommunications pervasive role– Web-enabled e-business processes

– Electronic commerce

– Enterprise collaboration

– Other applications • Business operations, management, strategic objectives

Wireless Technologies

6-26

The Wireless Web

• Web-enabled appliances proliferate– Smart telephones, pagers, PDAs– All are very thin clients in wireless networks

6-27

Telecommunications Processors

• Modems

– Most common type

– Modulation and demodulation

• Converts for transmission over telephone lines

• Digital signal to analog

• Analog to digital

6-28

Communications Processors

6-29

Comparing Technologies

6-30

Telecommunications Software

• May reside in PCs, servers, mainframes, and communications processors

– Vital part of all telecommunications networks

– Used to manage network performance

– WANs often use telecommunications monitors or teleprocessing monitors

– Other networks use operating system software

– Middleware helps diverse networks communicate with each other

6-31

Network Management Functions

• Traffic Management

• Security

• Network Monitoring

• Capacity Planning

6-32

Network Topologies

6-34

Network Architectures and Protocols

• Protocol– Rules and procedures

• Handshaking– Exchanging predetermined to agree on a

protocol

• Network Architecture

– Master plan of standards

– Goal is to promote an open, simple, flexible, and efficient telecommunications environment

6-35

OSI Model

• Open Systems Interconnection Model– Seven-layer standard for network architectures

– Controls how messages should be transmitted

– Ensures consistency among products

6-36

OSI and TCP/IP Models

6-37

Transmission Speeds

6-38

RWC 3: Value of Secure Networks

• Improves operational efficiency• Secures sensitive data• Contains costs• Enhances employee connectivity• Enhances customer responsiveness• Allows customers to securely track orders in

real time• Empowers customer-service agents with

detailed account information• Provides easy, inexpensive videoconferencing

6-39

• Wi-Fi fast-growing popularity• Wi-Fi coffee shops replaced cybercafes• Moves towards free• Advertising offsets costs or to make money• Increasingly always free everywhere

RWC 4: Future of Public WiFi