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5 Chapter 8
Telecommunications, Networks,
and Wireless Computing
5 ©0008 by Prevece We
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مت یی تم مت و میت ات وتف
Obevwes
. What are the features of a contemporary
corporate telecommunications system? On
what major technology developments are
they based?
. What telecommunications transmission
media should our organization use?
. What kind of networks and network services
are appropriate for our organization?
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مت یی تم مت و میت ات وتف
هه
4. What telecommunications
applications can be used for
electronic business and electronic
commerce?
5. What issues should be addressed in
telecommunications planning?
8.3 ©0008 by Prevece ادنلا"
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مت یی تم مت و میت ات وتف
Oe Ola ree
1. Selecting appropriate technologies for
enterprise networking
2. Managing bandwidth
8.4 ©0008 by Prevece ادنلا"
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مت یی تم مت و میت ات وتف
۱ Ca
Telecommunications System
¢ Facilitation of electronic communication
* Telephone systems
* Broadcast and cable TV
¢ Radio, satellite, and local area networks
¢ Internet
¢ Analog or digital
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مت ی مت تس يي رف
۱ Ca
مس مهم متا مت مت متا
Three Major Developments Shaping
Contemporary Systems
Client/server computing
Packet switching
3. TCP/IP and other communications
standards
©0008 by Preece ادنلا"
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مت یی تم مت و میت ات وتف
۱ Ca
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مت یی تم مت و میت ات وتف
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مس مهم متا مت مت متا
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
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مت یی تم مت و میت ات وتف
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مس مهم متا مت مت متا
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
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و مود و ما سس
CO eh eee aA eet hace
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مس مت ملس ص بط مت سب زا
Packet Number
‘Message Number
Destination
Reassembled
Message
Packet 3
Prue O-O
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مت یی تم مت و میت ات وتف
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مس مهم متا مت مت متا
TCP/IP
Transmission Control Protocol/Internet Protocol
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
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مت یی تم مت و میت ات وتف
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Opstiews یتمه ررو وم مصه0) oP ویو
TCP/IP: Four-Layer Reference Model
Application layer: Communication between
applications and other layers
Transport layer: Acknowledging and
sequencing packets to/from application
Internet layer: Addressing, routing, packaging
data packets
Network interface layer: Placing packets on
and receiving them from network medium
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مت یی تم مت و میت ات وتف
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The Trewwesios Ovuirl Propo! tercet Protocol (TOPMP) rePerewer wodel
Computer A Computer B
[wei | سس
I
=a تفت
1
co تناع
1
Network
Interface
Prue مو
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مت یی تم مت و میت ات وتف
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Trews Orda
* Twisted wire
* Copper wire twisted in pairs
* Older analog transmission medium
* Can be used for digital signals
* Modems used for translating analog to digital
٠ Coaxial cable:
* Insulated copper wire
٠ Faster, more interference-free than twisted
pair
¢ Difficult to install; doesn’t support analog
signals
8.14 ©0008 by Prevece ادنلا"
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مت یی تم مت و میت ات وتف
۱ Ca
the wodeuw و ی
Digital ‘Analog Digital
و سیب
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مت یی تم مت و میت ات وتف
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Trews Orda
¢ Fiber optics
* Strands of clear glass fiber bound into
cables
* Data sent as pulses of light
* Faster, lighter, more durable
٠ Difficult to install; more expensive
٠ 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
8.16 ©0008 by Preece ادنلا"
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مت یی تم مت و میت ات وتف
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0 م1
Wireless Transmission *
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
8.17 ©0008 by Prevece ادنلا"
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مت یی تم مت و میت ات وتف
ال Sl Sa هس زر
Prequewy ranes Por cram nindion weds ond devices
fad Wore ogre سم رورا ما ما
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مت یی تم مت و میت ات وتف
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مو سب
by Preece Wd 0008© 8.19
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مت یی تم مت و میت ات وتف
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2 مویومعو
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
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مت یی تم مت و میت ات وتف
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Low vost
igh vost
©0008 by Preece ادنلا"
Treewesion Orda
Transmission Speed
Op 7 (OO Obps
Op t COO+ Obps
Op t COO+ Obps
Op tt GOO Dbps
Op t2 OF Mbps
Pwisted wire
Dirnwae
Ovuxial rable
Piber-vpiic cable
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مت یی تم مت و میت ات وتف
ad 0ت
Lovd ®reu Detworks
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
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و مود و ما سس
MU Li ee رد
Prue O-P
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مت یی تم مت و میت ات وتف
0 Oa a
‘Star topology Ring topology
3
Bus topology
و سب
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مت یی تم مت و میت ات وتف
ad 0ت
Orekss Detworks: OHP سس( مه
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
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و مود و ما سس
MU Li ee رد
ad 0ت
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مت یی تم مت و میت ات وتف
ad 0ت
ص0۳ له 2۳۳ تعسو Orekss
٠ Hot spot: Geographic location in
which an access point provides public
Wi-Fi network service
٠ Bluetooth: Standard for wireless
personal area networks that can
transmit up to 722 Kbps within 10-
meter area
8.27 ©0008 by Prevece ادنلا"
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مت یی تم مت و میت ات وتف
ad 0ت
جا 0 67۰ 0
٠ Span broad geographic distances
٠ Can consist of combination of:
٠ Switched lines
* Dedicated lines
* Microwave
* Satellite communications
٠ Private WANs expensive to support
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مت یی تم مت و میت ات وتف
ad 0ت
جا 0 67۰ 0
٠ Metropolitan Area Network (MAN)
* Scope between LAN and WAN
¢ Limited distance; faster and less
expensive than WAN
٠ Value-Added Networks
* Private, third-party managed, data only
networks
* Subscription basis
8.29 ©0008 by Preece ادنلا"
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مت یی تم مت و میت ات وتف
ad 0ت
هام0۲ مه سول
Is the World Falling for Wi-Fi?
* What management, organization, and
technology factors account for
different patterns of Wi-Fi adoption in
various countries?
٠ What value can Wi-Fi service provide
to businesses?
8.30 ©0008 by Preece ادنلا"
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مت یی تم مت و میت ات وتف
ad 0ت
جح ف حاصجاتت 11 لیاسو( roadbard
Frame relay
Asynchronous transfer mode (ATM)
Integrated Services Digital Network
(ISDN)
Digital subscriber line (DSL)
T1 line
Network convergence
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مت یی تم مت و میت ات وتف
UC Ce el arn Oar a cca م و۱۱9
Cevirow Odi od Groupware
٠ E-mail
¢ Eliminates telephone tag and costly
long-distance telephone charges
* Groupware
¢ Enables work groups at different
locations to participate in discussion
forums and work on shared documents
and projects
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مت یی تم مت و میت ات وتف
UC Ce el arn Oar a cca م و۱۱9
Orndow va Oucngeoet
Monitoring Employees on Networks:
Unethical or Good Business?
Should managers monitor employee e-
mail and Internet usage? Why or why
not?
Describe an effective e-mail and Web
use policy for a company.
©0008 by Preece ادنلا"
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مت یی تم مت و میت ات وتف
UC Ce el arn Oar a cca م و۱۱9
Ove Dut cord Pox
٠ Voice mail
* Digitizes spoken message and transmits
it over a network
۰ Fax
* Digitizes and transmits documents over
telephone lines
8.34 ©0008 by Preece ادنلا"
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مت یی تم مت و میت ات وتف
UC Ce el arn Oar a cca م و۱۱9
VebvoPerewhn, OorooPereariag, vad OnteoroPereurtay
¢ Teleconferencing
¢ Ability to confer with a group of people
simultaneously
٠ Data conferencing
* Two or more users can edit and modify
data files simultaneously
* Videoconferencing
* Participants are able to see each other
over video screens
8.35 ©0008 by Prevece ادنلا"
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مت یی تم مت و میت ات وتف
UC Ce el arn Oar a cca م و۱۱9
Ong Portion Gervices, Ostowe Learcieg, ord عوجر
٠ Digital Information Services:
* Online services providing general and
business information, such as
LexisNexis, AOL, Dow Jones News
٠ Distance learning
* Education or training delivered over a
distance to individuals in one or more
locations
٠ E-learning
¢ Instruction delivered online using the
Internet or private networks
8.36 ©0008 by Preece ادنلا"
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مت یی تم مت و میت ات وتف
UC Ce el arn Oar a cca م و۱۱9
Chiro: Onis Interchae
Computer-to-computer exchange
between two organizations of standard
transaction documents, such as
invoices, purchase orders
Minimizes paper-handling and data
input; lowers transaction costs
Transmits structured data with fields,
unlike e-mail
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مت یی تم مت و میت ات وتف
Me eA ل همم
(B01) هه مول سس
Seller Customer
Purchase orders
Payments
Shipping novices
ene ‘Computer
Price updates
Invoices
Prue 0-10
8.38 ©0008 by Preece Ws
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مت یی تم مت و میت ات وتف
مه موه موی و Ce
٩1و Issues: Gevea Paros
Distance
Services
Points of access
Utilization
Cost
Security
Connectivity
oO Gee SS i
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مت یی تم مت و میت ات وتف
9
Ol Dew Oprtews Keep Deke ۶
. Analyze Delta using the competitive
forces and value chain models.
. What is Delta’s business strategy?
What is the role of information
systems and telecommunications
technology in this strategy?
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مت یی تم مت و میت ات وتف
9
Ol Dew Oprtews Keep Deke ۶
3. Assess Delta’s Digital Nervous System
(DNS) effort. What value does it
provide the company? How does it
support Delta’s business strategy?
4. What problems at Delta can be solved
with information systems? What
problems cannot be solved with
systems?
8.41 ©0008 by Preece ادنلا"
