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Enterprise manage information systems 6th by laudon ch08

Chapter 8

Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

Telecommunications, Networks,
and Wireless Computing

8.1

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

Objectives

1. What are the features of a contemporary
corporate telecommunications system? On what
major technology developments are they based?

2. What telecommunications transmission media
should our organization use?
3. What kind of networks and network services are
appropriate for our organization?

8.2

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

Objectives

4. What telecommunications applications can be
used for electronic business and electronic
commerce?
5. What issues should be addressed in
telecommunications planning?

8.3

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

Management Challenges

1. Selecting appropriate technologies for enterprise
networking
2. Managing bandwidth

8.4

© 2005 by Prentice Hall



Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System

Telecommunications System








8.5

Facilitation of electronic communication
Telephone systems
Broadcast and cable TV
Radio, satellite, and local area networks
Internet
Analog or digital

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Features of Contemporary Telecommunications Systems
Three Major Developments Shaping
Contemporary Systems

1. Client/server computing
2. Packet switching
3. TCP/IP and other communications standards

8.6

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
A corporate telecommunications system

Figure 8-1
8.7

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Features of Contemporary Telecommunications Systems

Client/Server Computing


Powerful personal computers connect to network
with one or more server computers



Has extended networking to parts of business that
could not be served by centralized architecture



Processing load balanced over many smaller
machines

8.8

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Features of Contemporary Telecommunications Systems

Packet Switching


Messages broken into “packets” before
transmission



Packets include destination and error-checking
information



Packets travel independently using routers;
reassembled into original message at destination

8.9

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Packet-switched networks and packet communications

Figure 8-2
8.10

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Features of Contemporary Telecommunications Systems

TCP/IP
Transmission Control Protocol/Internet Protocol






8.11

Open suite of protocols for connectivity developed in
1970s
Provides standards for breaking messages into packets,
routing them to destination addresses, and reassembling
them at end
Allows for communication regardless of
hardware/software

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Features of Contemporary Telecommunications Systems

TCP/IP: Four-Layer Reference Model
1.

Application layer: Communication between applications
and other layers

2.

Transport layer: Acknowledging and sequencing packets
to/from application

3.

Internet layer: Addressing, routing, packaging data packets

4.

Network interface layer: Placing packets on and receiving
them from network medium

8.12

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
The Transmission Control Protocol/Internet Protocol (TCP/IP) reference model

Figure 8-3
8.13

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Transmission Media


Twisted wire







Coaxial cable:





8.14

Copper wire twisted in pairs
Older analog transmission medium
Can be used for digital signals
Modems used for translating analog to digital
Insulated copper wire
Faster, more interference-free than twisted pair
Difficult to install; doesn’t support analog signals

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Functions of the modem

Figure 8-4
8.15

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Transmission Media


Fiber optics









8.16

Strands of clear glass fiber bound into cables
Data sent as pulses of light
Faster, lighter, more durable
Difficult to install; more expensive
Used in high-capacity optical networks
Currently slowed by need to convert back and
forth to electrical data
Can use multiplexing; allows one channel to carry
several transmissions

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Transmission Media



Wireless Transmission






8.17

Use electromagnetic spectrum
Microwave and infrared use high-frequency radio
signals
Paging systems, cellular telephones, PDAs,
mobile data networks
Wireless communication requires compatible
standards
Security/privacy issues

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Frequency ranges for communication media and devices

Figure 8-5
8.18

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Amoco’s satellite transmission system

Figure 8-6
8.19

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Transmission Media







8.20

Transmission Speed
Bps: Bits per second
Baud rate: Rate of signal changes
One signal change = cycle
Transmission capacity is function of frequency
Bandwidth: Range of frequencies
accommodated on a particular channel

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

The Corporate Telecommunications System
Transmission Media

Transmission Speed

8.21

Twisted wire

Up to 100 Mbps

Microwave

Up to 200+ Mbps

Satellite

Up to 200+ Mbps

Coaxial cable

Up to 200 Mbps

Fiber-optic cable

Up to 6+ Tbps

Low cost

High cost

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

Communications Networks
Local Area Networks








8.22

Connects computers and other digital devices
within 2000 ft radius
Cabling or wireless technology links computers,
network interface cards, and software
Ethernet
Network Operating System (NOS)
Client/server or peer-to-peer architecture
Star, bus, and ring topologies

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

Communications Networks
A local area network (LAN)

Figure 8-7
8.23

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

Communications Networks
Network topologies

Figure 8-8
8.24

© 2005 by Prentice Hall


Essentials of Management Information Systems, 6e
Chapter 8 Telecommunications, Networks, and Wireless Computing

Communications Networks
Wireless Networks: Wi-Fi and Bluetooth






8.25

Use radio waves to connect stations
802.11b: Current standard; 54 Mbps in 2.4 GHz
range
Infrastructure mode: Wireless devices
communicate with wired LAN via access points
Ad-hoc mode: Peer-to-peer mode; wireless
devices communicate with each other directly

© 2005 by Prentice Hall


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