Transcript Communications and Networks

Chapter 8
Communications and Networks
Professor Michael J. Losacco
CIS 1150 – Introduction to Computer Information Systems
Overview
Chapter
8
Discuss Connectivity
Discuss The Wireless Revolution
Describe Communication Channels
Discuss Connection Devices
Discuss Connection Services
Describe Data Transmission Factors
Describe Different Types Of Networks
Describe Network Architectures
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Communications
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Connectivity
Use Networks to Link People and Resources
The Wireless Revolution
Stay Connected with Anyone Anywhere Any Time
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Uses
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Wireless Messaging
Text Messaging
Advantages
Forces Us to be Concise
Message is Available for Reference by All Parties
Writing Helps Us to Think More Carefully
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Uses
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Wireless Messaging
Text Messaging
Disadvantages
Carries No Tone Which Can Lead to Misinterpretation
Impersonal
No Opportunity for Group Discussion
Picture Messaging
Send / Receive Graphics, Pictures, Video
Sexting: 54%
28% Photographic
Drexel U. 2014
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Uses
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GPS (Global Positioning System)
Signals Sent by Satellites Orbiting Earth
Signal Sent Every 1/1000 of a Second
Earth-based Receivers Analyze Signals
Determine Receiver’s Geographic Location
Groupware
Assists Groups in Working Together
Share Data Over Network
e.g., Schedule Meetings
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Uses
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Web Services
Software Applications
Communicate with Other Remote Computers
Use Internet or Internal Business Network
Mashup
Combines Services from Multiple Sources
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Communication Systems
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Basic Elements
Sending and Receiving Devices
Communication Channel
Connection Devices
Data Transmission Specifications
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Communication Channels
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Physical Connections
Twisted-pair Cable
Telephone Lines
Ethernet Cables
Used in Networks to Connect Variety of Components
Coaxial Cable
Over 80x Capacity of Twisted-pair
Fiber-optic Cable
Over 26,000x Capacity of Twisted-pair
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Communication Channels
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Wireless Connections
Bluetooth
Short-range Radio Signals (33 Feet)
Wi-Fi (Wireless Fidelity)
High-frequency Radio Signals
Microwave
Line-of-sight
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Communication Channels
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Wireless Connections
WiMax
Extends Range of Wi-fi Networks Using Microwaves
LTE (Long Term Evolution)
Currently Similar to WiMax with Future Speed Benefits
Satellite
Microwave Relay Stations in Space
Uplink / Downlink
Affected by Weather
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Connection Devices
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Modem
Modulation – Digital to Analog
Demodulation – Analog to Digital
Transfer Rate
Bps – Bits per Second
Typically Mbps
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Connection Devices
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Modem
Types
Telephone
Connect Computer Directly to Telephone Line
Cable
Uses Same Coaxial Cable as Your Television
Wireless
Portable High-speed Connectivity From Virtually Anywhere
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Connection Services
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Cable
Uses Existing TV Cable
Satellite Connection Services
Use Almost Anywhere
Slower than Cable Modem
Cellular Services
4G Using WiMax and LTE
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Data Transmission
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Bandwidth
Measurement of Capacity of Channel
Categories
Voiceband
Broadband
Cable and Satellite
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Data Transmission
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Protocol
Collection of Procedures
Establish, Maintain, & Terminate Transmissions
Type of Error Checking Used
Data Compression Method, If Any
Indicate Finished Sending Message
Indicate Message Has Been Received
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Data Transmission
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Protocol
TCP/IP
Internet Standard
Identification
IP Addressing
Domain Name Server (DNS)
Packetization
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Networks
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Node
Any Device Connected to Network
Client
Node that Requests and Uses Resources
Server
Node that Shares Resources with Other Nodes
Directory Server
Manages Resources for Entire Network
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Networks
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Host
Any Computer System Accessed Over a Network
Router
Forwards Data Packets to Their Destination
Switch
Coordinates Flow of Data
NIC
NOS
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Network Types
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Local Area Network (LAN)
Home Network
Wireless LAN (WLAN)
Hotspots
Wide Area Network (WAN)
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Network Architecture
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Topologies
Describes How a Network is Arranged
Bus
Ring
Star
Tree
Mesh
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Network Architecture
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Strategies
How Resources are Coordinated and Shared
Client/Server
Server Provides Access to Resources for Clients
P2P (Peer-to-peer)
Can Act as Both Client and Server
File Sharing
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Organizational Networks
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Internet Technologies
Intranet
Private Network Within An Organization
Extranet
Private Network
Provides Limited Access To Network
Vendors
Customers
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Organizational Networks
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Network Security
Firewall
Proxy Server
Controls Access to Network
Intrusion Detection System (IDS)
Analyzes Incoming and Outgoing Traffic
Virtual Private Network (VPN)
Secure Connection to Company Network
For Mobile Users, Vendors, & Customers
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Careers in IT
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Network Administrator
Manage Company LAN and WAN Networks
Network Design, Implementation, Maintenance
Plan and Implement Network Security
Bachelor's Degree in Computer Science
Good Communication Skills
Annual Salary of $46,000 - $84,000
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