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C·R·E·A·T·E for Mississippi - Copyright ©2004. All rights reserved.
Wireless Networking: A View from within Mississippi Schools Sean Owen and Peter GravesC·R·E·A·T·E for MississippiMECA 2004
C·R·E·A·T·E for Mississippi - Copyright ©2004. All rights reserved.
What is Wireless?• Telecommunications in which EM
waves carry a signal
• Cell phones, pagers, GPS, garage door openers
• Baby monitors, cordless phones
• Wireless LANs
C·R·E·A·T·E for Mississippi - Copyright ©2004. All rights reserved.
What is a WLAN?• Wireless Local Area Network
• Mobile users connect to a LAN via Wireless Means
• Wireless Connection via a standard, IEEE 802.11
• Many 802.11 standards currently being implemented
C·R·E·A·T·E for Mississippi - Copyright ©2004. All rights reserved.
Current Wireless Standards• 802.11B (WiFi)
• 11 Mbps, 2.4 GHz, 32 users/AP• 3 years• Actual throughput: 4.5 Mbps• Turbo Mode APs approach the true range
• 802.11A (WiFi5)• 54 Mbps, 5 GHz, 64 users/AP• Less Interference, Shorter Range
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Upcoming Wireless Standards• 802.11g
• 54 Mbps, 2.4 GHz• Backward compatible with 802.11b• Was ratified in May 2003
• 802.11i• Focus on security and authentication• Made Available Q4 2003• New Protocols and Encryption Methods
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WLAN Components• Access Points
• (WAP or AP)• Varying designs
• Wireless NICs• Network Interface Cards• Multiple Types
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What is an Access Point?• Access Transmits and receive data
• WLAN to LAN connection
• All APs are not created equal.• Antenna• Power• Components
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Cisco Aironet 350 Access Point• 802.11b
• 11 Mbps shared
• Dual External Antennas
• www.cisco.com
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Apple AirPort Extreme
• Contains Antenna, LAN,& USB Ports
• Can Act as a Bridge
• Integrated Antenna
• http://www.apple.com/airport/
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Linksys Dual-Band WiFi Router
• 4-Port Switch
• Tri-Standard
• Dual-Band
• http://www.linksys.com/products/product.asp?grid=33&scid=35&prid=537
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Orinoco AP-1000
• Dual PC Card Slots
• Interoperability
• Integrated Antenna
• www.orinocowireless.com
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SMC 4-port Wireless Router • Features
• 3-port switch
• Print Server
• Built-In Firewall
• www.smc.com
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Wireless Signal Performance
Data Rate
Range
11 MB/s Up to 100’
5.5 Mb/s Up to 150’
2 Mb/s Up to 300’
This signal performance chart is based on an open, optimal This signal performance chart is based on an open, optimal environment which does not take into account physical barriers or environment which does not take into account physical barriers or the number of users sharing the signal. This is a chart based on the number of users sharing the signal. This is a chart based on the 802.11b standard.the 802.11b standard.
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Access Point Placement
• Range indoors ~ 300 feet ~ B or G• Overlap ranges; Pools Bandwidth• Promotes “roaming” for users
Access Point A
Access Point CAccess Point B
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Wireless Cards• Desktops
• Internal or external• External – USB with antenna
• Laptops• Most widely used• Internal or external• 64- and 128-bit varieties• Based on WEP
C·R·E·A·T·E for Mississippi - Copyright ©2004. All rights reserved.
Wireless Considerations• Users Per Access Point
• Typically 15-20 users• Shared bandwidth
• WLAN range• Indoors or outdoors• Open area or closed• Physical Barriers• Number of Clients Sharing Access Point
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Benefits of Wireless• Avoids infrastructure issues
• Cabling problems
• Cost of wiring
• Long Distance Connections• Building to Building without Leased Lines
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Wireless Concerns
• Security• SSID• Access Lists• WEP• WPA
• Power Over Ethernet• PoE– Allows APs to be placed in unique places
without the need for an outlet• External - Power Injectors • Built-In on Some Models
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VPN – Virtual Private Networking
• Sample schematic
C·R·E·A·T·E for Mississippi - Copyright ©2004. All rights reserved.
Checklist• Equipment Inventory
• Evaluate physical Barriers
• Assess Networking Needs
• Prepare for Security Needs
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