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321450321450 Management Management of of I nf or mat i oI nf or mat i o
n n TechnologyTechnology
321450321450 Management Management of of I nf or mat i oI nf or mat i o
n n TechnologyTechnology
Chapter 8Chapter 8
Telecommunication Technology
Asst. Prof. Wichai Bunchua Asst. Prof. Wichai Bunchua- E mail : wichai@buu.ac.th- E mail : wichai@buu.ac.th
http://http://www.informaticswww.informatics.buu.ac.th/~wichai.buu.ac.th/~wichai
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 44 4
Telecommunications Electronic transmission of signals for
communications Telecommunications medium
Any material substance that carries an electronic signal to support communications between a sending and receiving device
Telecommunications protocol Defines set of rules that governs the
exchange of information over a communications medium
An Overview of An Overview of TelecommunicationsTelecommunicationsAn Overview of An Overview of TelecommunicationsTelecommunications
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wichai@buu.ac.thwichai@buu.ac.th 55 5
An Overview of An Overview of Telecommunications Telecommunications (cont.)(cont.)
An Overview of An Overview of Telecommunications Telecommunications (cont.)(cont.)
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wichai@buu.ac.thwichai@buu.ac.th 66 6
Synchronous communications Receiver gets message
instantaneously Asynchronous communications
Receiver gets message after some delay
An Overview of An Overview of Telecommunications Telecommunications (cont.)(cont.)
An Overview of An Overview of Telecommunications Telecommunications (cont.)(cont.)
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wichai@buu.ac.thwichai@buu.ac.th 77 7
Basic Telecommunications Basic Telecommunications Channel CharacteristicsChannel CharacteristicsBasic Telecommunications Basic Telecommunications Channel CharacteristicsChannel Characteristics
Simplex channel Transmits data in only one direction
Half-duplex channel Transmits data in either direction, but
not simultaneously Full-duplex channel
Permits data transmission in both directions at the same time
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 88 8
Basic Telecommunications Basic Telecommunications Channel Characteristics Channel Characteristics (continued)(continued)
Basic Telecommunications Basic Telecommunications Channel Characteristics Channel Characteristics (continued)(continued)
Channel bandwidth Rate at which data is exchanged
Telecommunications media Categories: guided transmission media and
wireless Guided transmission media types
Available in many types Twisted-pair wire
Classified by category: Category 1, 2, 3, 4, 5, 5E, and 6
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 99 9
Basic Telecommunications Basic Telecommunications Channel Characteristics Channel Characteristics (continued)(continued)
Basic Telecommunications Basic Telecommunications Channel Characteristics Channel Characteristics (continued)(continued)
Coaxial cable Offers cleaner and crisper data
transmission (less noise) than twisted-pair wire
Fiber-optic cable Transmits signals with light beams
Broadband over power lines Potential problem: transmitting data over
unshielded power lines can interfere with both amateur (ham) radio broadcasts and police and fire radios
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 101010
Basic Telecommunications Basic Telecommunications Channel Characteristics Channel Characteristics (continued)(continued)
Basic Telecommunications Basic Telecommunications Channel Characteristics Channel Characteristics (continued)(continued)
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wichai@buu.ac.thwichai@buu.ac.th 121212
Basic Telecommunications Basic Telecommunications Channel Characteristics Channel Characteristics (continued)(continued)
Basic Telecommunications Basic Telecommunications Channel Characteristics Channel Characteristics (continued)(continued)
Wireless communications options Wireless transmission
involves the broadcast of communications in one of three frequency ranges
Radio, microwave, or infrared frequencies
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wichai@buu.ac.thwichai@buu.ac.th 131313
Frequency Ranges Used for Frequency Ranges Used for Wireless CommunicationsWireless Communications
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 141414
Short Range Wireless Short Range Wireless OptionsOptionsShort Range Wireless Short Range Wireless OptionsOptions
Near Field Communication (NFC) Short-range wireless connectivity
technology designed for cell phones and credit cards
Bluetooth Wireless communications specification that
describes how cell phones, computers, personal digital assistants, etc., can be interconnected
Ultra wideband (UWB) Transmits large amounts of digital data over
short distances of up to 30 feet
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 151515
Short Range Wireless Short Range Wireless Options (continued)Options (continued)Short Range Wireless Short Range Wireless Options (continued)Options (continued)
Infrared transmission Sends signals at a frequency of 300
GHz and above Zigbee
Form of wireless communications frequently used in security systems and heating and cooling control systems
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 161616
Medium Range Wireless Medium Range Wireless OptionsOptionsMedium Range Wireless Medium Range Wireless OptionsOptions
Wi-Fi Wireless telecommunications technology
brand owned by the Wi-Fi Alliance Wireless access point
Consists of a transmitter with an antenna, receives the signal, and decodes it
Wi-Fi access points Have maximum range of about 300 feet
outdoors and 100 feet within a dry-walled building
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wichai@buu.ac.thwichai@buu.ac.th 181818
Wide Area Wireless Wide Area Wireless Network OptionsNetwork OptionsWide Area Wireless Wide Area Wireless Network OptionsNetwork Options
Microwave transmission High-frequency (300 MHz - 300 GHz) signal
sent through the air Common forms of satellite communications
Geostationary satellite Low earth orbit (LEO) satellite Very small aperture terminal (VSAT)
Wireless mesh Uses multiple Wi-Fi access points to link a
series of interconnected local area networks
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 191919
Wide Area Wireless Wide Area Wireless Network Options Network Options (continued)(continued)
Wide Area Wireless Wide Area Wireless Network Options Network Options (continued)(continued)
3G wireless communications Useful for business travelers, people on
the go, and people who need to get or stay connected. Rate 2 Mbps. Normally 384 Kbps
4G wireless communications Will provide increased data transmission
rates in the 22-40 Mbps range Worldwide Interoperability for
Microwave Access (WiMAX) Set of IEEE 802.16 wireless metropolitan
area network standards
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 202020
Future Wireless Future Wireless Communications Communications DevelopmentsDevelopments
Future Wireless Future Wireless Communications Communications DevelopmentsDevelopments
Digital signal Represents bits
Analog signal Variable signal, continuous in both
time and amplitude so that any small fluctuations in the signal are meaningful
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 212121
Networks and Distributed Networks and Distributed ProcessingProcessingNetworks and Distributed Networks and Distributed ProcessingProcessing
Computer network Consists of communications media,
devices, and software needed to connect two or more computer systems or devices
Can transmit and receive information to improve organizational effectiveness and efficiency
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 222222
Network TypesNetwork Types Network TypesNetwork Types Personal area networks
Supports interconnection of information technology within a range of about 33 feet
Local area networks Connects computer systems and devices
within a small area (e.g., office or home) Metropolitan area networks
Connects users and their devices in a geographical area that spans a campus or city
Wide area networks Ties together large geographic regions
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 252525
Client/Server SystemsClient/Server SystemsClient/Server SystemsClient/Server Systems
Client/server architecture Multiple computer platforms are
dedicated to special functions Client
Any computer that sends messages requesting services from the servers on the network
Database server Sends only the data that satisfies a
specific query, not the entire file
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wichai@buu.ac.thwichai@buu.ac.th 262626
Client/Server SystemsClient/Server SystemsClient/Server SystemsClient/Server Systems
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wichai@buu.ac.thwichai@buu.ac.th 2727
The Client/Server The Client/ServerNetworksNetworks
The Client/Server The Client/ServerNetworksNetworks
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 282828
Client/Server Systems Client/Server Systems (cont.)(cont.)Client/Server Systems Client/Server Systems (cont.)(cont.)
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 292929
Telecommunications Telecommunications HardwareHardwareTelecommunications Telecommunications HardwareHardware
Modems Modulation/demodulation devices
Multiplexers Combines data from multiple data sources
into a single output signal that carries multiple channels
Front-end processors Special-purpose computers that manage
communications to and from a computer system
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 3030
Telecommunications Telecommunications Hardware (cont.)Hardware (cont.)Telecommunications Telecommunications Hardware (cont.)Hardware (cont.)
30
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 3131
Telecommunications Telecommunications Hardware (continued)Hardware (continued)Telecommunications Telecommunications Hardware (continued)Hardware (continued)
Private branch exchange (PBX) Telephone switching exchange that serves a
single organization Switches, bridges, routers, and gateways
Switch: Uses the physical device address in each incoming message on the network
Bridge: Connects one LAN to another LAN that uses the same telecommunications protocol
Router: Forwards data packets across two or more distinct networks toward their destinations
Gateway: Serves as an entrance to another network
31
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 3232
Telecommunications Telecommunications Hardware (cont.)Hardware (cont.)Telecommunications Telecommunications Hardware (cont.)Hardware (cont.)
32
Switch:
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 3333
Telecommunications Telecommunications Hardware (cont.)Hardware (cont.)Telecommunications Telecommunications Hardware (cont.)Hardware (cont.)
33
Bridge: Router: Gatew
ay:
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 343434
Telecommunications Telecommunications SoftwareSoftwareTelecommunications Telecommunications SoftwareSoftware
Network operating system (NOS) Systems software that controls the
computer systems and devices on a network
Network management software Protects software from being copied,
modified, or downloaded illegally Performs error control to locate
telecommunications errors and potential network problems
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 353535
Securing Data Securing Data TransmissionTransmissionSecuring Data Securing Data TransmissionTransmission
Encryption Converting an original message into a
form that can only be understood by the intended receiver
Key Variable value that is applied (using an
algorithm) to a set of unencrypted text to produce encrypted text or to decrypt encrypted text
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 363636
The Encryption ProcessThe Encryption ProcessThe Encryption ProcessThe Encryption Process
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 373737
Securing Data Securing Data Transmission (continued)Transmission (continued)Securing Data Securing Data Transmission (continued)Transmission (continued)
Securing wireless networks Wired equivalent privacy (WEP)
Used encryption based on 64-bit key, which has been upgraded to a 128-bit key
Wi-Fi Protected Access (WPA) Security protocol that offers significantly
improved protection over WEP War driving
Involves hackers driving around with a laptop and antenna trying to detect insecure wireless access points
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 383838
Other Encryption MethodsOther Encryption MethodsOther Encryption MethodsOther Encryption Methods
Data Encryption Standard (DES) Early data encryption standard
developed in the 1970s that uses a 56-bit private key algorithm
Advanced Encryption Standard (AES) Extremely strong data encryption
standard based on a key size of 128 bits, 192 bits, or 256 bits
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 393939
Virtual Private Network Virtual Private Network (VPN)(VPN)Virtual Private Network Virtual Private Network (VPN)(VPN)
Private network that uses a public network (usually the Internet) to connect multiple remote locations
Supports secure, encrypted connections between a company’s private network and remote users
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 404040
Telecommunications Telecommunications Services and Network Services and Network ApplicationsApplications
Telecommunications Telecommunications Services and Network Services and Network ApplicationsApplications
Cellular phone services Operate using radio waves to provide
two-way communications Picocell
Miniature cellular base station designed to serve a very small area such as part of a floor inside a building
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 414141
Cellular Phone Services Cellular Phone Services Cellular Phone Services Cellular Phone Services
Digital subscriber line (DSL) Service Telecommunications service that
delivers high-speed Internet access Voice over Internet Protocol (VoIP)
Services Enables voice conversations to be
converted into packets of data that can be sent over a data network
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 434343
VoIP Options VoIP Options VoIP Options VoIP Options
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 444444
Linking Personal Linking Personal Computers to Mainframes Computers to Mainframes and Networksand Networks
Linking Personal Linking Personal Computers to Mainframes Computers to Mainframes and Networksand Networks
Basic way that telecommunications connect users to information systems Connecting personal computers to
mainframe computers so that data can be downloaded or uploaded
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 454545
Voice MailVoice MailVoice MailVoice Mail
Users can send, receive, and store verbal messages for and from other people around the world
Reverse 911 service Delivers emergency notifications to
users in a selected geographical area Voice-to-text services
Convert speech to text so that you can manage voice mails more effectively
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 4646
Asynchronous Digital Subscriber Asynchronous Digital Subscriber LineLine ((ADSLADSL))Asynchronous Digital Subscriber Asynchronous Digital Subscriber LineLine ((ADSLADSL))
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 474747
Home and Small Business Home and Small Business NetworksNetworksHome and Small Business Home and Small Business NetworksNetworks
DSL modem Enables each computer in the
network to access the Internet Firewall
Filters the information coming from the Internet into your network
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 484848
Electronic Document Electronic Document DistributionDistributionElectronic Document Electronic Document DistributionDistribution
Lets you send and receive documents in a digital form without printing them
Much faster to distribute electronic documents via networks than to mail printed forms
Viewing documents on screen instead of printing Saves paper and document storage space
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 494949
Call CentersCall CentersCall CentersCall Centers
Physical location where an organization handles customer and other telephone calls
Used by: Customer service organizations Telemarketing companies Computer product help desks Charitable and political campaign
organizations
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 505050
Telecommuting and Telecommuting and Virtual Workers and Virtual Workers and WorkgroupsWorkgroups
Telecommuting and Telecommuting and Virtual Workers and Virtual Workers and WorkgroupsWorkgroups
Telecommuters Need to be strongly self-motivated,
organized, focused on their tasks with minimal supervision
Jobs unsuitable for telecommuting Those that require frequent face-to-
face interaction, need much supervision, and have many short-term deadlines
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 515151
VideoconferencingVideoconferencingVideoconferencingVideoconferencing
Enables people to hold a conference by combining voice, video, and audio transmission
Reduces travel expenses and time Increases managerial effectiveness
through: Faster response to problems, access to
more people, and less duplication of effort
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 525252
Electronic Data Electronic Data InterchangeInterchangeElectronic Data Electronic Data InterchangeInterchange
Idea behind EDI Connecting corporate computers
among organizations EDI
Can link the computers of customers, manufacturers, and suppliers
Eliminates the need for paper documents and substantially cuts down on costly errors
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 535353
Two Approaches to EDITwo Approaches to EDITwo Approaches to EDITwo Approaches to EDI
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 545454
Public Network ServicesPublic Network ServicesPublic Network ServicesPublic Network Services
Give personal computer users access to vast databases, the Internet, and other services Usually an initial fee plus usage fees Fees are based on services used; can range
from under $15 to over $500 per month Providers of public network services
include Microsoft, America Online, and Prodigy
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 5555
เครื�อข่�าย ผู้��ให้�บรื�การืบรื�ษั�ท กสท . โทรืคมนาคม จำ�าก�ด (มห้าชน )
http://www.cat.net.th/
บรื�ษั�ท อ�นเทอรื�เน�ตปรืะเทศไทย จำ�าก�ด (มห้าชน ) http://www.inet.co.th/
บรื�ษั�ท สามารืถอ�นโฟเนต จำ�าก�ด http://www.samarts.com/
บรื�ษั�ท ท'ท'แอนด�ท' จำ�าก�ด (มห้าชน )http://www.ttt.co.th/
บรื�ษั�ท ท'โอท' จำ�าก�ด (มห้าชน )http://www.tot.co.th/
บรื�ษั�ท ซี'เอส ล็�อกซีอ�นโฟ จำ�าก�ด (มห้าชน )http://www.csloxinfo.com/
บรื�ษั�ท ทรื� อ�นเทอรื�เน�ต จำ�าก�ด http://www.trueinternet.co.th/
Public Network ServicesPublic Network ServicesPublic Network ServicesPublic Network Services
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 565656
Electronic Funds TransferElectronic Funds TransferElectronic Funds TransferElectronic Funds Transfer
Transfers money from one bank account directly to another without the use of paper money
Used for both credit and debit transfers
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 575757
Distance LearningDistance LearningDistance LearningDistance Learning
Use of telecommunications to extend the classroom Instructors create course home pages on
the Internet Students access the course syllabus and
instructor notes on the Web page Student e-mail mailing lists allow students
and the instructor to e-mail one another Chat groups allow students to form “virtual
teams”
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 585858
Shared WorkspaceShared Workspace Shared WorkspaceShared Workspace
Common work area where: Colleagues can share documents,
issues, models, schedules, spreadsheets, and all forms of information
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 595959
SummarySummarySummarySummary
Telecommunications and networks Creating profound changes in business because
they remove the barriers of time and distance Communications
Can be classified as synchronous or asynchronous
Telecommunications media can physically connect data communications devices Guided transmission media and wireless media
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 606060
Summary (continued)Summary (continued)Summary (continued)Summary (continued)
Wireless communications solutions for very short distances include: Near field communications, Bluetooth, ultra
wideband, infrared transmission, and Zigbee Transborder data flow
Electronic flow of data across international and global boundaries
Client/server system Network that connects a user’s computer (a
client) to one or more host computers (servers)
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 6161
Questions?Questions?Questions?Questions?
1 201January 1 201January11
wichai@buu.ac.thwichai@buu.ac.th 6262
Assignment#8Assignment#8Assignment#8Assignment#8
8 a . การสื่��อสื่ารทางไกล (Telecommunication) สื่�มพั�นธ์�ก�บระบบสื่ารสื่นเทศอย่�างไร จงย่กตั�วอย่�างประกอบ
8 b . จงบอกองค์�ประกอบ 6 อย่�างของระบบการสื่��อสื่ารทางไกล (Telecommunication) พัร อมอธ์!บาย่หล�กการท#างานพั�$นฐานของระบบ
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