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Transcript of Understanding Computers, Chapter 1knautzfamilywi.com/documents/05_Networks_V1.0.0.pdf · CSCI 105...
Homeschool Enrichment
Computer Networks
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Overview
• This chapter covers:– Networking concepts and terminology – Common networking and communications
applications– Technical issues related to networks, including
the major types of networks, how data is transmitted over a network, and types of transmission media involved
– Explanation of the various ways networked devices communicate with one another
– Various types of hardware used in conjunction with a computer network
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
What Is a Network?
• Network: a connected system of objects or people• Computer network: a collection of computers
and other hardware devices connected together so that users can share hardware, software, and data, as well as electronically communicate with each other
• Internet: largest computer network• Uses:
– Sharing: interet connection, software, hardware, working collaboritively
– Communicating: email, messaging, etc.
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Networking and Communications Applications
Phone Service, paging systems, messaging
Monitoring Systems
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Networking and Communications Applications, cont'd
Global Positioning Systems
Videoconferencing, collaborative computing & telecommuting
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Networking and Communications Applications, cont'd
Telemedicine
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Types of Networks
• Networks can be identified by their
– Topology (physical arrangement)
– Architecture (the way they are designed to communicate)
– Size (how large of an area the network services)
Network Topologies
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Network Architectures
Client / Server
Peer-to-peer
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
LANs, WANs, and Other Types of Networks
• Personal area network (PAN): connects personal devices for one individual, such as his or her portable PC, cell phone, and portable printer
• Local area network (LAN): covers a relatively small geographical area, such as a home, office building, or school
• Wide area network (WAN): covers a large geographical area; may consist of two or more LANs, which could be relatively close to one another (such as in the same city) or far apart
• Intranet: private network, such as a company LAN, set up by an organization for use by its employees
• Extranet: Intranet that is at least partially accessible to authorized outsiders
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Data Transmission Characteristics
• How does the data get from point A to point B?– Data can travel over a network in different
ways– Each network has its own characteristics– Issues:
• Wired vs. wireless• Speed• Analog vs. digital• Type & timing• Delivery method
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Data Transmission Characteristics
• Wired networks: the PC is physically cabled to the network– Common in schools, business, and government
facilities– High speed than wireless
• Wireless networks: typically use radio waves to send data through the air– Popular in homes and businesses– Wireless hotspots are commonly available in
public locations
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Data Transmission Characteristics, cont'd
• Bandwidth (throughput): amount of data that can be transmitted over a communications medium at one time (higher bandwidth will deliver data faster)
• Analog vs. digital: continuous wave vs. discrete 0s and 1s
• Serial vs. parallel transmission types– Serial: one bit a time– Parallel: at least one byte at a
time
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Data Transmission Characteristics, cont'd
Transmission timing
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Data Transmission Characteristics, cont'd
Delivery method
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Wired Network Transmission Media
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Wireless Network Transmission Media
• Broadcast radio transmissions– Short-range (such as Bluetooth)– Medium-range (such as Wi-Fi)
• Microwave and satellite transmissions• Cellular Radio Transmission
– Use cellular towers within cells– Calls are transferred from cell tower to cell tower
as the individual moves
• Infrared (IR) Transmissions– IR keyboards and mice– Requires line-of-sight
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Communications Protocols
• Communications protocol: an agreed-upon standard for transmitting data between two devices on a network
• Protocols specify how– Devices physically connect to a network– Data is packaged for transmission– Receiving devices acknowledge signals
(handshaking)– Errors are handled
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Communications Protocols: Ethernet
• Ethernet: a widely used communications protocol for LANs– Typically used with LANs that have a bus or star
topology and use twisted-pair or coaxial cables– Original Ethernet networks run at 10 Mbps; most
now do 100 Mbps and many can do 1 Gbps– Utilizes a set of procedures (CSMA/CD) to send
data and make sure it arrives
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Communications Protocols: Wi-Fi (802.11)
• Wi-Fi (802.11): family of wireless networking standards for wireless Ethernet
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Communications Protocols: Bluetooth
Bluetooth: communications standard for very short-range wireless connections (within 10 meters or 33 feet)
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Networking Hardware
• Network adapters: used to connect a PC to a network
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Networking Hardware, Cont’d
• Hubs, switches, routers, and wireless access points: used to connect devices and route data to the devices on a network– Hub: all data goes to all devices– Switch: data goes to just appropriate device– Router: more efficiently delivers data– Wireless access point: connects wireless
devices to a wired network– Some devices contain more than one of these
capabilities
CSCI 105 – Understanding Computers Today & Tomorrow: Chapter 7 – Computer Networks
Summary
• What Is a Network?
• Networking and Communications Applications
• Types of Networks
• How Does Data Travel Over a Network?
• Communications Protocols
• Networking Hardware