Business Computing 550 Lesson 2. Fundamentals of Information Systems, Fifth Edition Chapter 4 Telecommunications, the Internet, Intranets, and Extranets.

Business Computing550

Lesson 2

Fundamentals of Information Systems, Fifth Edition

Chapter 4 Telecommunications, the Internet,

Intranets, and Extranets

An Overview of Telecommunications

• Telecommunications– The 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

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Channel Bandwidth

• The rate at which data is exchanged

• Broadband communications– A telecommunications system that can exchange

data very quickly

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Communications Media

• Guided transmission media types– Many utilities, cities, and organizations are

experimenting with broadband over power lines (BPL)

• Wireless technologies– Broadcast of communications in one of three

frequency ranges: microwave, radio, and infrared– Near Field Communication (NFC)– Bluetooth– Ultra wideband (UWB)– Wi-Fi

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Telecommunications Hardware

• Devices include: – Modems, multiplexers, PBXs and front-end

processors that enable electronic communications to occur or occur more efficiently

• Switches, bridges, routers and gateways – Devices for sending packets of data through one or

more networks

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Services

• Digital subscriber line (DSL)– Telecommunications service that delivers high-

speed Internet access to homes and small businesses over the existing phone lines

• Asymmetric DSL (ADSL) line – Does not require an additional phone line and yet

provides “always-on” Internet access

• Voice over Internet Protocol (VoIP)– Enables voice conversations to be converted into

packets of data that can be sent over a data network

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Networks and Distributed Processing

• Computer network– Communications media, devices, and software

needed to connect two or more computer systems and/or devices

• Network nodes– Computers and devices on the networks

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Network Types

• Personal area network (PAN)– Wireless network that connects information

technology devices within a range of 33 feet or so

• Local area network (LAN)– Connects computer systems and devices within a

small area, such as an office

• Metropolitan area network (MAN)– Connects users and their computers in a geographical

area

• Wide area network (WAN)– Connects large geographic regions

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Distributed Processing

• Centralized processing– All processing occurs in a single location or facility

• Decentralized processing– Processing devices are placed at various remote

locations

• Distributed processing– Computers are placed at remote locations but

connected to each other via a network

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Client/Server Systems

• Multiple computer platforms are dedicated to special functions, such as:– Database management, printing, communications,

and program execution

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Communications Protocols

• Set of rules that govern the exchange of information over a communications channel

• Protocols – Govern several levels of a telecommunications

network

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Communications Software

• Network operating system (NOS)– Systems software that controls the computer

systems and devices on a network and allows them to communicate with each other

• Network management software– Simplifies the process of updating files and programs

on computers on the network