Chapter 5: Telecommunications, Wireless Technologies, and Computer Networks

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Chapter 5 Telecommunications, Wireless
Technologies, and Computer Networks

• Succeeding with Technology Second Edition

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Objectives

• Understand the fundamentals of data
  communications and the criteria for choosing a
  communications medium
• Explain how networking media, devices, and
  software work together to provide data networking
  services, and describe the benefits of various
  types of media

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Objectives (continued)

• List and describe the most popular forms of
  wireless telecommunications technologies
• List the different classifications of computer
  networks and their defining characteristics, and
  understand the basics of wireless home networking

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Fundamentals of Telecommunications

• Communications
• Transmission of a signal by way of a medium
• Signal
• Contains message comprised of data and
  information
• Communication medium
• Anything that carries a signal between a sender
  and a receiver

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Telecommunications and Data Communications

• Telecommunications
• Electronic transmission of signals for
  communications
• Data communications
• Electronic transmission and reception of digital
  data
• Telecommunications network
• Connects communications and computing devices
• Networking media
• Anything that carries an electronic signal

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Characteristics of Telecommunications

• Analog signal
• Fluctuates continuously
• Digital signal
• Discrete voltage
• State is either high or low
• Bandwidth
• Data transmission rate
• Measured in bits per second (bps)
• Broadband
• Connection that is always on or active

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Networking Media, Devices, and Software
Networking Media

• Twisted pair cable
• Consists of pairs of twisted wires covered with
  an insulating layer
• Coaxial cable
• Consists of an inner conductor wire surrounded by
  insulation, a conductive shield, and a cover
• Fiber-optic cable
• Consists of thousands of extremely thin strands
  of glass or plastic bound together in a sheathing

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Networking Devices

• Modems
• Modulates and demodulates signals
• Cable modem
• Provides Internet access over a cable television
  network
• DSL modem
• Provides high-speed Internet service over
  telephone lines
• Network adapter
• Computer circuit board, PC Card, or USB device

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Network Control Devices

• Hubs
• Used as a central point for connecting a series
  of computers
• Switches
• Fundamental part of most networks
• Repeaters
• Connect multiple network segments
• Bridges
• Connect two or more network segments

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Network Control Devices (continued)

• Gateways
• Network points that act as an entrance to another
  network
• Routers
• Can divide a single network into two logically
  separate networks
• Wireless access point
• Receives and transmits data to wireless adapters
  
• Firewall
• Device or software that filters the information
  coming onto a network

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Industrial Telecommunications Media and Devices

• Microwave transmission
• Also called terrestrial microwave
• Line-of-sight medium
• Communications satellite
• Basically a microwave station placed in outer
  space

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Industrial Hardware

• T1 line
• Carries twenty-four 64-Kbps signals on one line
• T3 line
• Carries 672 signals on one line
• Devices commonly used to control and protect
  industrial-level telecommunications
• Multiplexer
• Communications processor
• Encryption devices

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Networking Software

• Monitors the load, or amount of traffic, on the
  network
• Can provide data security and privacy
• Network administrator
• Person responsible for setting up and maintaining
  the network

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Networking Software (continued)

• Network Operating Systems
• Perform same functions for network as operating
  system software performs for a computer
• Network Management Software
• Facilitates monitoring of individual computers
  and shared hardware
• Communications Protocols and Standards
• Ethernet most widely used network standard for
  private networks

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Wireless Telecommunications Technology - Cell
Phone Technologies

• Cellular network
• A radio network
• Geographic area is divided into cells with a
  transceiver antenna and station at the center of
  each cell
• Cellular carrier
• Company that builds and maintains cellular
  network
• Provides cell phone service to the public

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Cellular Service Plans

• Calling plans are defined by usage in three time
  frames
• Whenever, or anytime, minutes with no time
  restrictions
• Weeknight minutes
• Monday through Friday, 900 p.m. to 559 a.m. or
  659 a.m.
• Weekend minutes
• Saturday 1200 a.m. to Sunday 1159 p.m.

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Pagers

• Small, lightweight devices that receive signals
  from transmitters
• Types of paging systems
• National and regional systems
• Set up transmission towers to cover large
  geographic areas
• On-site paging systems
• Use small desktop transmitters to send pages over
  a small wireless network

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Global Positioning Systems

• Uses satellites to pinpoint the location of
  objects on earth
• Using a GPS receiver and a network of 24
  satellites
• GPS can tell exact location of receiver on the
  earths surface
• GPS
• Originally developed for national security and
  later extended for public use

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Wireless Fidelity and WiMAX

• Wireless fidelity (Wi-Fi)
• Makes use of access points to wirelessly connect
  users to networks within a range of 2501000
• Standards
• Known as the 802.11 family of standards
• Developed by the Institute of Electrical and
  Electronics Engineers (IEEE)
• Developed to support wireless computer networking
  within a limited range at broadband speeds

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Wireless Fidelity and WiMAX (continued)

• WiMAX
• Known as IEEE 802.16
• Faster and longer range than Wi-Fi
• WiMAX antenna has 31-mile range
• Perfect for city-wide Internet access
• Seattles Space Needle has a WiMAX antenna
• Intel and Nokia are strongly supporting WiMAX

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Bluetooth

• Enables digital devices to communicate directly
  with each other wirelessly over short distances
• Communicates at speeds of up to 1 Mbps within a
  range of up to 33 feet (10 meters)
• Can connect devices to a computer network using
  access points like Wi-Fi
• Bluetooth and Wi-Fi
• Compete in some areas, but have unique qualities

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Infrared Transmission

• Involves sending signals through the air via
  light waves
• Slower than both Bluetooth and Wi-Fi
• Uses light rather than broadcast technology
• Ideal for secure data transmissions

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Radio Frequency Identification (RFID)

• Uses tiny transponders in tags that can be
• Attached to merchandise or other objects
• Read using an RFID transceiver or reader for the
  purpose of identification
• Primarily used to track merchandise from supplier
  to retailer to customer

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Networks and Distributed Computing

• Within a private network
• Computing resources are shared in order to
  maximize computing power
• Computer
• Includes devices for input, processing, storage,
  and output
• Components can be distributed throughout a
  computer network

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Computer Networking Concepts

• Nodes
• Devices attached to a network
• Workstations
• Computers attached to a network
• Local resources
• Files, drives, or other peripheral devices
  connected to the workstation and accessible via
  the network
• Network resources
• Workstation accesses over the network
• Distributed Computing
• Multiple remote computers working together

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Network Types

• Personal area network (PAN)
• Interconnecting personal information technology
  devices
• Local Area Network (LAN)
• Connects computer systems within same building
• Intranet
• Uses protocols of the Internet and the Web within
  the confines of a private network
• Virtual Private Network (VPN)
• Enables private Internet communications

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Network Types (continued)

• Metropolitan area network (MAN)
• Connects networks within a city or
  metropolitan-size area into a larger high-speed
  network
• Wide area network (WAN)
• Connects LANs and MANs between cities, across
  country, and around the world
• Global Networks
• A WAN that crosses an international border
• Electronic Data Interchange (EDI)
• Connects corporate computer systems

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Home Networks

• Allow residents to
• Share a single Internet connection
• Share a single printer between computers
• Share files such as images, music, and programs
• Back up copies of important files to another PC
  for safekeeping
• Participate in multiplayer games.
• Share output from devices such as a DVD player or
  Webcam

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Summary

• Telecommunications
• Refers to the electronic transmission of signals
  for communication
• Types of cables used in telecommunications
• Twisted pair cables, coaxial cable, and fiber
  optic cable
• Networking devices include
• Modems, network adapters, network control
  devices, RFID devices, and pagers

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Summary (continued)

• Cellular network
• Radio network
• Geographic area is divided into cells with a
  transceiver antenna (tower) and station at the
  center of each cell
• Server computers
• Used to distribute data, files, and programs to
  users, or clients, on the network
• Home networks
• Used to share hardware, files, and a common
  Internet connection