chapter 5: telecommunications and networks
Post on 07-Nov-2014
1.014 Views
Preview:
DESCRIPTION
TRANSCRIPT
Chapter 5: Telecommunications
and NetworksSucceeding with Technology: 2005 Update Edition
Succeeding with Technology 2
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
Succeeding with Technology 3
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
Succeeding with Technology 4
Telecommunications and Data Communications Telecommunications
Electronic transmission of signals for communications
Data communications Electronic collection, processing, and distribution of
data Telecommunications network
Connects communications and computing devices Networking media
Anything that carries an electronic signal
Succeeding with Technology 5
Characteristics of Telecommunications Analog signal
Continuously changes over time
Digital signal
At any given time is either high or low
Signal frequency
Speed at which signal can change from high to low
Succeeding with Technology 6
Succeeding with Technology 7
Succeeding with Technology 8
Transmission Capacities
Bandwidth Range of signal frequencies that can be sent over a
given medium at the same time Broadband media
Significantly faster than narrowband Any media faster than 200 Kbps (kilobits per
second) or 2 Mbps (megabits per second) Narrowband
Anything below 200 Kbs
Succeeding with Technology 9
Succeeding with Technology 10
Networking Media Twisted-pair cable
Cable consisting of pairs of twisted wires Repeaters
Used to boost signal so that it can travel longer distances
Coaxial cable Inner conductor wire surrounded by insulation, a
conductive shield, and a cover Fiber-optic cable
Thousands of thin strands of glass or plastic bound together in a sheathing
Succeeding with Technology 11
Succeeding with Technology 12
Networking Media (Continued) Microwave transmission
High-frequency radio signal that is sent through the air
Communications satellite
A microwave station placed in outer space
Global positioning system (GPS)
Uses satellites to pinpoint the location of objects on earth
Succeeding with Technology 13
Succeeding with Technology 14
Succeeding with Technology 15
Networking Media (Continued) Wireless fidelity (Wi-Fi)
Wireless networking devices that use the 802.11 protocol
Uses wireless access points Bluetooth
Enables digital devices to communicate wirelessly over short distances
Communicates at speeds of up to 1 Mbps within a range of up to 33 ft
Infrared transmission Sending signals through the air via light wave
Succeeding with Technology 16
Succeeding with Technology 17
Networking Devices
Modems Modulates and demodulates signals Cable modem
Provides Internet access over a cable television network
DSL modem Connects digital devices using a digital signal over
telephone service (POTS) lines Network adapter
Computer circuit board, PC Card, or USB device
Succeeding with Technology 18
Succeeding with Technology 19
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
Succeeding with Technology 20
Network Control Devices (Continued) Gateway
A network point that acts 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
Succeeding with Technology 21
Radio Frequency Identification (RFID) Devices
Tiny microprocessor combined with an antenna
Tracks merchandise from supplier to retailer to customer
Succeeding with Technology 22
Succeeding with Technology 23
Summary
Telecommunications Electronic transmission of signals for communication
Computer network Connects computers for data communications
Network media Cables and wireless signals
Networking devices Modems, network adapters, network control
devices, RFID devices, and pagers
top related