wireless by fanzhongqing


									         Wireless Internet
An technology overview and guide to effective
  use at home, work, and in the classroom.

                    Larry MacPhee
                   e-Learning Center
               Northern Arizona University
• Found on older PDAs,
  Laptops, Printers
• Requires Line-of-sight
• Short range
• Flaky
• Not widely adopted
• Now used mostly for remotes
        GPRS and Cell Phones
• Discussion for another day
  But consider how
  these devices can
  be used in the
  classroom by
  students…with or
  without instructor
• Bluetooth http://www.bluetooth.com
• Named after Danish King Harald “Bluetooth”
  Blaatand (910-985 AD), credited with uniting
  Denmark and Norway.
   –   Radio waves
   –   “Short” range (30 ft.)
   –   Computer to Mouse, Keyboard, Cell Phone, PDA
   –   Data rate: 1 Mbps (megabits per second)
•   Wi-Fi = wireless fidelity
•   http://www.wi-fi.org
•   IEEE 802.11 protocol
•   “Long” range (~150 ft)
•   Uses Radio Frequency (RF)
  What we mean by “wireless”
• An extension of an existing Internet
  – Not a stand-alone connection
• Allows computers to connect to:
  – other computers (directly)
  – local networks and devices
  – the Internet
               Ways to Connect
• PC to PC          • PC to Wireless Access Point
  – (Ad Hoc)
                      – (Infrastructure) “Hot Spot”
                    What do I need?
1.       Computer
     •    Wi-Fi card
     •    Built-in wireless

2. Wireless Access Point (WAP)
     •    Public or Private?
     •    Open or Secure?
     •    Free or Paid?
    Does my PC have Wi-Fi?
Start / Control Panel / Network Connections

   •If you see “Wireless Network Connection” you’re all set!
   •Double-click to see available networks
Joining a Wi-Fi Network: Win XP

     Open              Secure
Joining a Wi-Fi Network: Mac
  On the Mac, Wi-Fi is called “AirPort”
    Adding Wireless Capabilities
•Laptop $30 to $60+ for 802.11g
   •PC card (PCMCIA)
   •External USB

• Desktop $30 - $60+ for 802.11g
   •PCI card
   •External USB

• Where to buy?
   •NAU bookstore
   •Computer store
   •Office supply store
      Setting up a WAP at home
• High Speed Internet Connection
   – Cable Modem
   – DSL Modem
• Instructions vary, but are usually poor!
• Apple, Linksys, Belkin, D-Link are good brands
• Take the time to set up the security!
• Skill Level Required: Intermediate to High
            Finding a Hot Spot
• Search the web:

• Scan your locale:
  – “stumbler” software
  – hotspot finder gizmo.
         Public Hot Spots in Flagstaff
Free (Usually Open)      Paid (Usually Secure)
•   Late For the Train   •   Kinko’s

•   Macy’s               •   Barnes and Noble
                         •   Campus Coffee Bean
•   Uptown Billiards
                         •   Starbucks
•   Pay ‘n’ Take
                         •   Embassy Suites
•   NAU (Guest access)
                         •   UPS Store
•   Know of Others?
                         •   Varsity Espresso
                         •   McDonald’s
                         •   Days Inn
           Access Points at NAU
University Union                   Institute for Human Development
Dubois Center                      Hotel/Restaurant Management
Learning Resources Center          Health Professions
Information Technology Services    Facilities Services
Eastburn Education Center          Colorado Plateau Studies
Engineering and Technology         Riles
Babbitt Administrative Center      Biology
Project Management Office          Ashurst
Physical Sciences                  Social and Behavioral Sciences
College of Business                North Union
Southwest Forest Science Complex   Nursing
Wettaw Biology/Biochemistry        Cline Library
Gateway Center                     Gammage

                          WAPs at NAU
          Connecting at NAU
• http://www.nau.edu/wireless
• VPN – for security

• Solution Center at 3-1511 (faculty/staff)
      Current Wi-Fi Protocols
Protocol    Data Rate     Range     Compatibility
802.11b      11 Mbps       Long       First out
802.11a      54 Mbps       Short         No

802.11g      54 Mbps       Long        With b

  – Detailed Comparisons of a, b, and g
  – Performance degrades on mixed b/g networks
           Future Wi-Fi Protocols
Protocol    Data Rate      Range         Compatibility

802.11n     100 Mbps+       Longer           b and g
                           (~250 ft)

Wi-Max       70 Mbps       Longest           802.16
                           (5 - 30 mi)

  • Pre-802.11n is being sold now
  • Wi-Max promises very long distance
     • (ideal when Cable and DSL are not practical)
     Wireless Speed & Range
• A “g” base station can transmit at
  maximum data rate (54 Mbps) up to about
  50 ft, but declines to 11 Mbps by 150 ft.

•   Max range ~ 500 ft. outdoors
•   Physical site conditions vary
•   Antennas can help
•   Signal is omni-directional
Roaming Wirelessly
                Wi-Fi Interference
• “b” and “g” use RF in 2.4 GHz range
• 11 channels, but…

• Interference from
   –   Microwave Ovens
   –   Cordless Phones
   –   Bluetooth Devices
   –   Baby Monitors

• More reading…
                    Wireless Security
Why Use Security?                   • Hide your SSID
   – To Control Access to WAP
   – To Protect Confidential Data   • Restrict MAC Addresses
                                    • Use Data Encryption
                                       – 40 Bit WEP
                                       – 128 Bit WEP
                                       – WPA
                                    • Use a VPN
                                    • Look for https:
       Geek fun: Build a Cantenna
•   Extend the range by shaping the signal
•   Point-to-point
•   Line of sight
•   10 miles?
•   Buy it
•   Build it!
 Geek Fun II: Wi-Fi Printing
Make your old laser printer wireless!

Skill Level: High
Cost: $100

          Classroom Uses of Wi-Fi
Advantages of a Mobile Laptop Lab:

•   Saves space
•   Multi-use room
•   Equipment sharing
•   Wireless Access Point
•   Charging
•   Printing
•   Security
•   Accountability
A Wired Classroom
A Wireless Meeting Place
Outdoor Roaming Wireless
A Wireless Lecture Hall
        Tablet PCs and PDAs?
• How can they be used?
• What advantages?
• What disadvantages?
               Final Thoughts
•   What if you don’t want Wireless?
•   IM during tests?
•   Bootleg WAPs
•   Unwelcome surfing?
•   WiFi free zone?
•   Enforcement? PDAs, Cell Phones, etc.
• Stephanie McCarthy - Graphics
• Don Carter - Additional Content
• Kevin Mackett - Additional Content

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