Lecture Management information systems: Solving business problems with information technology – Chapter 3

Introduction to MIS
Chapter 3
Networks and Telecommunications

Copyright © 1998-2002 by Jerry Post

Introduction to MIS

1


Internal

Networks

Teamwork
Communication
Scheduling
Sharing

Internet

External
Suppliers
Customers
Banks

 

Introduction to MIS

 

2


Outline


Introduction












Computers
Media
Connection Devices
Software



Shared Media
Switched

Introduction to MIS

 

Standards
The Internet













How the Internet Works
Internet 2
Mobile Commerce

Global Telecommunications


Network Structure


 

Sharing Data
Sharing Hardware
Sharing Software

Components of a Network






Technical Problems
Political Complications
Cultural Issues
Comment

Cases: Specialty Retail
Appendix: Creating Web
Pages

3


Sharing Data: Transactions

Internet

Database Management

System and Web Server

 

Introduction to MIS

 

4


Sharing Data: Decisions & Searches



Decisions & searches
Teamwork & joint authorship

Team Document

File Server and Database

Data
and
Tools

Report and
Comments

 

Introduction to MIS

 

5


Sharing Data: E-mail
Internet
2. Message
transferred to
account on
server.

3. Transferred
via the Internet
to the
destination
account.

1. User creates e-mail message.

 

Introduction to MIS

 

4. Message

received when
user checks email.

6


Sharing Data: Calendars

 

Introduction to MIS

 

8:00

Mgt meeting

8:30

(open)

9:00

Staff meeting

9:30

Staff meeting

10:00

new meeting

7


Hardware Sharing

Printers
Storage
Processors





tape drive
(backup)

Corporate or
external computer
access

Workstations

Shared
Printer





 

Server

Files are transferred from workstations to the server.
Software automatically copies files to tapes.
LAN administrator can restore files if needed.

Introduction to MIS

 

8


Packet-Switched Networks


Data, Voice, Video






All converted to packets
Packet has data, destination, and source address
Switched services

Sent as packets:
Voice
Packets routed as needed
B
2
Reassembled at destination Chicago

12345

New York
C
A

4
1

E

Atlanta
Dallas

5

Computer

 

Introduction to MIS

 

D

3
Sent as packets: A B C D E

9









Servers
Work stations

Media







Network Components

Computers

Personal Computer

Cables
Fiber optic
Radio
Infrared

Personal Computer

LAN card

LAN card

Connection devices

Internet
LAN card
Router or Switch
Firewall

 

Introduction to MIS

LAN card
Server

 

Shared Printer

10


Server Scalability
Server farms distribute
the workload. Add
more computers for
more power.
Increasing
performance
within a
product family.

Sun 10000

Rack mount
server farm.

Sun 3800

Compaq

Sun Ultra 5
 

Introduction to MIS

 

11


Network Transmission Media




Electricity
Fiber optics
Radio waves

Fiber Optic Cable
Example:
Long distance phone lines
reflective cladding

Twisted Pair
Example:
Local phone lines

glass or

plastic

Radio or Micro Waves
Example:
Cellular phones

Coaxial
Example:
Cable TV

antenna
Shield

 

Introduction to MIS

 

12


Fiber Optics





Faster
More data
Less magnetic interference
Long stretches without
repeaters

900 copper wires can be
replaced by one fiber

optic line (for telephone
connections).

 

Introduction to MIS

 

13


KH

1K

100K



Sound
Radio
Micro
Light

Frequency differences




Amount of data
Distance
Interference / Noise

:

VHF

1M

10M

88
M

54
M
FM

TV
:

HF

UHF
100M

Microwave Optical
1G

10G

Hertz

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Pu l i c
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

 

MF

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



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All waves behave similarly


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100



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z

/>

/>Introduction to MIS

 

14


Transmission Capacity

 

Introduction to MIS

 

A thin fiber optic cable can carry as much data as
900 single copper wires, with minimal
interference, and superior tensile strength.

15


The Importance of Bandwidth

 

Introduction to MIS

 

16


Shared Connections

With shared connections, machines have to take turns, and congestion
can slow down all connections.

With switched
connections, each
computer has the full
bandwidth of the
connection at all times.
Performance depends on
how fast the switch can
handle connections.

 

Introduction to MIS

 

17


Time Division
A

B

A
C

C

A

C

A time

D

Computers A and B split their messages into packets and share
the transmission medium by taking turns sending the data.

 

Introduction to MIS

 

18


A

B

frequency

Frequency Division

A

3500 Hz

C
C

D

Computers A and B split the frequency: A uses a higher spectrum.
By listening only to the assigned frequency, multiple transmissions
can occur at the same time.

 

Introduction to MIS

 

19


A

B

C

D

frequency

Spread Spectrum

time

Sharing a medium by both frequency and time is one method
of spread spectrum transmission. It is efficient for many computers
because the full bandwidth can be utilized over time and frequency.

 

Introduction to MIS

 

20


Wireless
Communication

Microwave transmissions are
used to provide communications
for cellular phones and laptop
computers. As prices of phones,

portable computers, and
communication costs decrease,
increasing numbers of workers
are choosing wireless
technologies.

 

Introduction to MIS

 

21





The need for standards
A changing environment

Connecting Networks

Internet
Backbone fiber optic
Routers or Switches
Switch

Hub
Hub

Radio-based network

 

Introduction to MIS

 

22


Shared-Media Network

Shared Media

Tap

 

Introduction to MIS

 

23


Switched Network
Switch

Servers

Workstations/PCs

 

Introduction to MIS

 

24


Enterprise Network

Building 1

Building 2
Fiber optic

Switch

Servers
Firewall

Workstations/PCs

Internet – ISP
Subsidiary

 

Introduction to MIS

 

25