Download Telecommunications and Networks

Chapter
6
Telecommunications
and Networks
McGraw-Hill/Irwin
Copyright © 2011 by The McGraw-Hill Companies, Inc. All rights reserved.
Learning Objectives
• 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
6-2
Learning Objectives
• 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
6-3
Learning Objectives
• Explain the concept of client/server
networking
• Understand the two forms of peer-topeer networking
• Explain the difference between digital
and analog signals
6-4
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
6-5
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
6-6
Telecommunication Trends
6-7
Telecommunications-Based Services
6-8
Value of Telecommunications Networks
6-9
Business Use of the Internet
6-10
Business Value of the Internet
Summary of bulleted list
6-11
Intranets as Information Portals
6-12
Extranet Connectivity
6-13
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
6-14
Telecommunications Network Model
6-15
Network Component Alternatives
6-16
Wide Area Network (WAN)
6-17
Local Area Network (LAN)
• Connects computers in a limited physical area
– Office, classroom, or building
6-18
Virtual Private Network
6-19
Client/Server Network
6-20
Network Computing
6-21
Peer-to-Peer Network Diagrams
6-22
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
6-23
Wireless Technologies
• 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
6-24
Wireless Technologies
• 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
6-25
The Wireless Web
• Web-enabled appliances proliferate
– Smart telephones, pagers, PDAs
– All are very thin clients in wireless networks
6-26
Telecommunications Processors
• Modems
– Most common type
– Modulation and demodulation
• Converts for transmission over telephone lines
• Digital signal to analog
• Analog to digital
6-27
Communications Processors
6-28
Comparing Technologies
6-29
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
6-30
Network Management Functions
• Traffic Management
• Security
• Network Monitoring
• Capacity Planning
6-31
Network Topologies
6-32
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
6-34
OSI Model
• Open Systems Interconnection Model
– Seven-layer standard for network architectures
– Controls how messages should be transmitted
– Ensures consistency among products
6-35
OSI and TCP/IP Models
6-36
Transmission Speeds
6-37
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
6-38
RWC 4: Future of Public WiFi
•
•
•
•
•
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
6-39