Title: Information Technology in Business: Telecommunications, Networks and Internet Basics
1Information Technology in Business
Telecommunications, Networks and Internet Basics
2Learning Objectives
- When you finish this chapter, you will
- Recognize why successful managers must be
familiar with telecommunications concepts and
terminology. - Know the principles of communication within a
computer system and among computers. - Be able to identify the major media and devices
that are used in telecommunications.
3Learning Objectives
- Be able to list and explain the functions of
different network layouts and the concept of
protocols. - Understand how telecommunications can improve
operations in organizations. - Know the latest developments in
telecommunications media and transmission speeds.
- Understand the historical development of the
Internet - Understand the main structural components of the
Internet - Understand how HTML, HTTP, browsers and servers
work together to form the WWW
4Telecommunications in Business
- Telecommunications
- Any form of long distance communication,
including telephone, television and radio - Telecommunications has improved business in three
main ways - Better communication
- Higher efficiency
- Better distribution of data
5What is Data Communications?
- Data Communications
- Any transfer of data within a computer, between a
computer and another device, or between two
computers - Integration
- Business are increasingly integrated in their use
of computers, telephony, video and data networks
6What is a Telecommunications System?
- Compatible hardware and software used to
communicate information from one place to another - Will include voice, text, graphics, documents and
video
7A Generalized Telecommunications System
- Hardware (Host computer, front end communication
processor, modem, multiplexor) - Communications media (Cable or wireless)
- Communications software
- Data communications providers
- Communications protocols
- Communications applications (EDI,
videoconferencing, EFT, etc.)
8Electronic Signals
- Analog
- Information imbedded in the changing
characteristics of the wave - Amplitude or frequency based
- Digital
- Information imbedded as 1 or 0, on or off
9Modulation
10Modulation
- Amplitude Modulation (AM)
- Frequency Modulation (FM)
- Phase Modulation
11Multiplexing
12Communications Devices
- Modems
- Devices that modulate and demodulate signals,
converting from analog to digital and digital to
analog - Multiplexers
- Devices that allow several telephones or
computers to transmit data through a single line - Frequency-division multiplexing
- Time-division multiplexing
- Front End Processors
13Channels and Media
- Communication Channel
- Physical medium through which data can be
communicated. - Channel Capacity
- Narrow band
- Broadband
14Channels and Media
- Media
- A medium is any means by which data can be
transmitted. - Transmission speed
- A mediums capacity is determined by the range of
bits per second at which it can operate. - Baud
- Repeater
15Channels and Media
- Twisted Pair
- Telephone line made of a pair of copper wires
twisted to reduce electromagnetic interference
(EMI) - Coaxial Cable
- Commonly used for cable television transmission
- More expensive than twisted pair
- Greater transmission rate than twisted pair
- Much less susceptible to EMI
16Channels and Media
- Microwaves
- High-frequency, short radio-frequency (RF) waves
- Terrestrial microwave
- Satellite microwave
- Optical Fiber
- Fiber-optic technology uses light instead of
electricity to transmit data. - Cellular and Wireless
- Radio frequency technologies
- Fixed or mobile
17Channels and Media
18Channels and Media
19Channels and Media
20A Variety of Services
Figure 6.15 Services offered by
telecommunications firms
21What is Data Communications?
22Communication Direction
- Three Modes of Communication Between Devices
- Simplex
- One direction only
- Half-Duplex
- Both directions, but only one at a time
- Full-Duplex
- Simultaneous in both directions
23Communication Direction
24Communication Direction
- Asynchronous Communication
- In asynchronous transmission, the devices are not
synchronized by any timing aids. - Advantage
- Does not need sophisticated and expensive timing
hardware - Disadvantage
- Overhead, time spent transmitting bits that are
not a part of the primary data
25Communication Modes
26Communication Modes
- Synchronous Communication
- In synchronous communication, data are
transmitted using timing devices. - Messages are transmitted in packets.
- Advantage of synchronous communication
- Overhead in synchronous communication is
significantly smaller than in asynchronous
communication.
27Communication Modes
28Protocols
- Definition
- Rules and procedures governing transmission
across a network - Line access
- Collision avoidance
- TCP/IP
- Standard protocol of the Internet and intranets
- Transmission Control Protocol/Internet Protocol
- Designed for sending large files across
unreliable networks - Utilizes packets of information
29OSI Standard
- Seven Layer Model
- Governs peer-to-peer communication between
software at each layer - From physical layer (how bits are transmitted
over a channel) - To application layer (file transfer, security,
etc)
30Open Systems Interconnect Model
31Networks
- LANs (Local Area Networks)
- Networks within a building, or within a group of
adjacent buildings - WANs (Wide Area Networks)
- Networks across significant distances, either
within a single organization or spanning multiple
organizations - Value-added networks (VANs)
- Wireless communication
32Network Topology
33Networks Devices
- Bridge
- Connects two networks at the data link layer
- Router
- Connects two networks at network layer
- Provides intelligent routing, some network
management functions and security - Gateways
- Connect networks using different protocols
- Switches
- Incorporate features of bridges and gateways
34Other Standards (or lack thereof)
- Operating Systems
- No standard exists
- Graphical User Interface
- X Windows
- Software Applications
- No standard for programming language, DBMS, etc.
35Client/Server Computing
- Enabled by proliferation of powerful desktop
computers and decentralized servers - Principle
- Processing functions divided between to separate,
distinct computers - One requests services of a server (the client)
- One delivers a service upon request (the server)
36Example of Client/Server Computing
- Email
- Email client (Outlook) sends request to POP
server for messages - POP Server receives and validates request to
download email - Client processes data received (formats,
displays, stores messages)
37Example of Client/Server Computing
- Database Transaction
- Client program running on PC sends query to DBMS
running on central server - DBMS on server parses and executes the query
- DBMS assembles resulting data (or status result)
and sends it to client - Client receives data and processes it (displays
it, sends message to user, etc)
38Benefits of Client/Server Computing
- Potential to reduce cost
- By offloading computing cycles to cheaper and
underutilized desktop PC - Improved performance
- Has enabled high-performing graphical user
interfaces