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Linux Guide to Linux Certification

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Transcript

  • 1. CWNA Guide to Wireless LANs, Second Edition Chapter One It’s a Wireless World
  • 2. Wireless Networks
    • First Meeting Agenda
    • Syllabus and Intro.
    • How to access class resources in your computer
    • Let’s get acquainted (forming groups)
      • Name
      • Industry certification
      • Networking or IT courses
      • Interests
      • Why you are taking the class
      • Expectations of yourself
      • Expectations of the instructor and the class
    • WebCT Login
  • 3. Objectives
    • Describe how wireless technology is used in daily activities
    • Tell how wireless local area networks are used in applications such as education, business, travel, construction, and other areas
    • Explain the advantages and disadvantages of wireless technology
  • 4. Real Life Wireless
    • What did Texas Department of Transportation do?
  • 5. A Day in the Life of a Wireless User: Home
    • Wireless data communication has been the driving force in the 21 st century
    • Hotspots : Locations where wireless data services are available
      • World-Wide growth rate: 350% a year
      • By 2007 revenue from hotspots will exceed $9 billion.
    • Wireless local area network (WLAN): Essentially identical to standard local area network (LAN)
      • Compare Ethernet LAN devices to Wireless LAN devices
      • Except devices not connected by wires
      • Can increase productivity (By how much?)
    • How do you use wireless at home?
  • 6. A Day in the Life of a Wireless User: Car
    • Bluetooth wireless standard: Enables short range wireless communication
      • Used in many small devices
    • How is Bluetooth used in a car ?
    • Bluetooth on the Road.
  • 7. A Day in the Life of a Wireless User: Office
    • Fixed broadband wireless: Wireless transmissions between immobile devices
      • Typically between office buildings
      • Utilizes small, customized antennas
      • Otherwise known as WiMax
    • Free space optics (FSO): Alternative to high-speed fiber optic transmissions
  • 8. A Day in the Life of a Wireless User: Field
    • Handheld devices used to connect to nearest cell tower
      • Cell tower connects to local telephone company
      • Telephone company connects to appropriate resources
        • Such as e-mail servers
  • 9. A Day in the Life of a Wireless User: On Site
    • Radio frequency identification (RFID) tags:
      • “Electronic barcodes”
      • Used to identify items
      • Can be read if anywhere within range of transmitted radio signal
        • Depending on device
  • 10. A Look at Wireless Technologies
    • Wireless technology woven throughout many aspects of life
    • Useful to get overview of some current technologies in today’s wireless world
  • 11. Wireless Local Area Networks (WLANs)
    • Wi-Fi (Wireless Fidelity): Based on standard that transmits at up to 11 Mbps
    • Computers on WLAN must have wireless network interface cards (wireless NIC or Wireless adapter)
      • Performs same basic functions as standard NIC, plus more
    • Access point (AP): Transfers signals between wireless NICs
    • Patch cable connects AP to wired LAN or Internet
  • 12. Wireless Local Area Networks (continued) Wireless LAN
  • 13. Wireless Local Area Networks (continued) Home wireless LAN
  • 14. Bluetooth
    • Low-power wireless data and voice transmission technology
    • Bluetooth devices communicate via radio modules
      • Link manager: Software that helps identify other Bluetooth devices, creates links between devices, and sends and receives data
    • Transmit data at up to 1 Mbps over 10 meters
    • Bluetooth devices within range of each other automatically connect
      • Master and slave
    • Piconet: Bluetooth network containing a master and at least one slave
  • 15. Telecommunications Links
    • Integrated Services Digital Networks (ISDN): Transmits at 256 Kbps
    • T-1 lines: Transmit at 1.544 Mbps
    • Cable modems: Use television cable connection
    • Digital subscriber lines (DSL): Use telephone lines
    • WiMax: Signal transmitted between antennas
      • Up to 75 Mbps and over up to 35 miles
      • Fixed Broadband
  • 16. Telecommunications Links (continued)
    • FSO: Transmit at speeds up to 1.25 Gbps over up to 4 miles
      • Line-of-site transmission
    Free space optics transceiver
  • 17. Telecommunications Links (continued) Wireless office technologies
  • 18. Cellular Telephony
    • Global Systems for Mobile (GSM) communications technology: Coverage includes most of US and parts of Europe and Japan
      • Transmission speeds up to 9.6 Kbps
      • Information transmitted based on Wireless Application Protocol (WAP)
        • Standard way to transmit, format, and display data for devices like cell phones and handheld devices
  • 19. Cellular Telephony (continued)
    • WAP cell phone runs a microbrowser that uses Wireless Markup Language (WML) instead of HTML
    • WAP gateway or proxy: Translates between WML and HTML
    WAP communications
  • 20. Radio Frequency Identification (RFID)
    • Like an electronic barcode:
      • Can contain larger amounts of updatable information
      • Information transmitted via radio waves
      • Range typically about 1 foot at 5 Mbps
    RFID tag http://news.bbc.co.uk/2/hi/science/nature/4545252.stm
  • 21. Wireless Technology Categories Typical wireless technologies
  • 22. Wireless LAN Applications: Education
    • Educational institutions some of first adopters of WLANs
      • Dramatic advantages in teaching and learning
    • Wireless LAN connections offer students important degree of freedom
    • WLAN technology translates into cost savings for colleges
      • Reduces need for wiring and infrastructure
      • Fewer computer labs necessary
  • 23. Wireless LAN Applications: Education (continued) Campus access point locations
  • 24. Wireless LAN Applications: Business
    • Wireless LAN technologies have significantly changed how business conducted
      • Meetings not confined to conference rooms
      • Easier to connect to network resources and Internet
      • Can create office in space where traditional infrastructure does not exist
  • 25. Wireless LAN Applications: Travel
    • Travel industry perhaps adopted wireless technologies more than any other industry
      • Many airport terminals provide wireless hotspots
      • Several large airlines providing wireless capabilities to passengers during flights
      • Some airlines use WLAN technology to communicate with aircraft on ground
      • Some airlines use WLAN technology to facilitate maintenance tasks
      • Some airlines use new wireless data service to send and receive messages
  • 26. Wireless LAN Applications: Construction
    • Wireless technology has greatly benefited construction industry
      • Better management of resources
      • Better management of paperwork
    • Construction equipment being fitted with wireless terminals
      • “Smart” equipment
      • GPS information can provide location information to within centimeters
  • 27. Wireless LAN Applications: Warehouse Management
    • New products arrive continuously
      • Must be inventoried and stored
    • Products being shipped must first be located then transferred to correct location and truck
      • Mistakes in inventory or inability to locate items can be devastating
      • Mark inventory with RFID tags
    • Warehouse management system (WMS) software: Can manage all activities from receiving through shipping
      • Utilize wireless technology
  • 28. Wireless LAN Applications: Public Safety
    • Public safety departments using WLANs and GSM to communicate information with public safety vehicles
      • City-owned buildings equipped with APs
      • Large volumes of data can be quickly downloaded to vehicles
        • e.g., building floor plans, photographs of criminal suspects, and maps
  • 29. Wireless LAN Applications: Healthcare
    • Wireless LAN point-of-care computer systems allow medical staff to access and update patient records immediately
      • Document patient’s medication administration immediately
      • Extensive use of RFID tags
        • Identify healthcare professionals, patients, medications
      • System verifies that medication being administered to correct patient in correct dosage
        • Eliminates potential errors and documentation inefficiencies
  • 30. Wireless LAN Applications: Healthcare (continued)
    • Documentation process takes place at bedside where care delivered
      • Improves accuracy
    • Hospital personnel have real-time access to latest medication and patient status information
    • Wireless technology also used in other medical areas:
      • e.g., video pills
  • 31. Wireless LAN Applications: Healthcare (continued) Video pill
  • 32. Wireless Advantages and Disadvantages: Advantages
    • Mobility: Primary advantage of wireless technology
      • Enables individuals to use devices no matter where users roam within range of network
      • Increasingly mobile workforce is characteristic of today’s business world
      • WLANs give mobile workers freedom while allowing them to access network resources
      • “Flatter” organizations: WLANs give team-based workers ability to access network resources needed while collaborating in team environment
  • 33. Wireless Advantages and Disadvantages: Advantages (continued)
    • Easier and Less Expensive Installation: Installing network cabling in older buildings difficult and costly
      • Wireless LAN is ideal solution
      • Eliminating need for cabling results in cost savings
        • Significant time savings as well
      • Allows offices to reorganize easily
    • Increased Reliability: Wireless LAN technology eliminates certain types of cable failures and increases overall network reliability
  • 34. Wireless Advantages and Disadvantages: Advantages (continued)
    • Disaster Recovery: Documented disaster recovery plan vital to every business
      • Hot site: Off-site facility that can run business’s operations if primary site is not available
        • Generally maintained by third party
        • Expensive
      • Cold site: Customer provides and installs equipment
        • Many businesses use cold sites and WLANs as major piece of disaster recovery plan
          • No consideration given to network cabling
  • 35. Wireless Advantages and Disadvantages: Disadvantages
    • Security: Wireless signals broadcast in open air
      • Security for wireless LANs is prime concern
        • Unauthorized users might access network
          • War driving
        • Attackers might view transmitted data
        • Employees could install rogue access points
        • Attackers could easily crack existing wireless security
          • Older wireless products have very weak security features
  • 36. Wireless Advantages and Disadvantages: Disadvantages (continued)
    • Radio Signal Interference: Signals from other devices can disrupt wireless transmissions
      • Or wireless device may be source of interference for other devices
      • e.g., Microwave ovens, elevator motors, photocopying machines, theft protection devices, cordless telephones
      • Solution: Locate source of interference and remove
    • Health Risks: Wireless devices emit RF energy
      • Not known if or to what extent low levels of RF might cause adverse health effects
  • 37. Summary
    • Wireless devices and technologies enable users to roam almost anywhere and remain connected to data and voice networks
    • A WLAN, also known as Wi-Fi, functions the same as a standard wired network except devices send radio frequency signals through the air instead of being connected to the network by cabling
    • Bluetooth devices communicate using small radio transceivers called radio modules that are built into microprocessor chips
  • 38. Summary (continued)
    • Two popular technologies are WiMax and free space optics (FSO)
    • Handheld devices can send and receive wireless signals using the Global System for Mobile (GSM) communications technology
    • RFID tags function as electronic barcodes
    • Wireless personal area networks (WPANs) cover technologies where the transmission generally extends only a few meters or feet, whereas wireless local area networks (WLANs) are generally restricted to 112 meters (375 feet)
  • 39. Summary (continued)
    • Wireless LAN applications can be found in industries in which employees need the freedom to conduct business without being confined to a specific location
    • Wireless LANs have significant advantages, including increased mobility, easier and less expensive network installations, increased network reliability, and disaster recovery
    • Some of the disadvantages of wireless LANs include security, radio signal interference, and health concerns