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Introduction
What is wireless networking Key issues Wireless technology and education Recommendations
What is wireless networking
Benefits
Reduced installation costsFlexibilityExtended reachNetworking Students’ ComputersEnhancing education
Disadvantages
Many rapidly evolving standards Security Management Cost of network cards in computers Performance Need to understand how signals propagate Point-to-point needs line of sight
Why so many standards?
2G
2G 3G
Blueetooth WLAN
IrDA
wired
MobilityVehicle
Walk
Fixed0.1 1 10 100 Data rate
Mb/s
2G Cellular3G BluetoothWireless LANIrDAWired LAN
Wireless networking standards
Infrared (IrDA) Radio (unlicensed – ISM and UNII)
IEEE (802.11)ETSI (HiperLAN)Bluetooth
(Mobile telephony) (Radio (licensed)) (Broadband fixed wireless access)
IEEE Standards
Standard Speed Approved in UK
Compatible
802.11 2 Mb/s 802.11b 11 Mb/s 802.11g 34 Mb/s 12 June
2003 Will come
802.11a 54 Mb/s Jan 2003 Working on it
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Security
Doing nothing is not an option Not as good as wired network
Greatest risk is that it is often not even turned on Can be easily monitored and used Basic security easily broken (at the moment)
Treat as insecure network (as external) Implement security
Threats
Eavesdropping Rogue access points Denial of service Any PC can access the network
Security Solutions
Wired Equivalence Privacy (WEP)
Additional solutionsCustom solution from network vendorUse a Virtual Private Network (VPN)Treat as insecure network (outside the firewall)
Security need be no greater than elsewhere
Performance
sufficient for text and images Not sufficient for video (especially multi-user)
802.11b 11 Mb/s Shared 802.11g 802.11a
34 Mb/s
54 Mb/s
Shared
Shared Wired LAN 10-100 Mb/s Per user ADSL 0.5 Mb/s Per user
or shared
Signal propagation
Signals partially blocked by walls, plumbing etc.
Signals “leak” through walls Can only have limited number of access
points in an area Maximum distance for point-to-point – beware
trees!
Undertake a site survey
Reduced Installation costs
Less equipment Less cabling No need to flood wire May be only solution in rural areas
Increased flexibility and reach
No need to flood wire Can be connected to the network anywhere
Anywhere in a “room”Can cover areas that you would not wire
• Public spaces – like cafes• Outdoors – smokers can access email from their cars• The whole resource centre / library
Networking students’ computers
Increasing number of students have their own PC
Increasingly this is portable PDA or laptop Students want to be able to use them in
college Wireless simplifies these issues
Access is where the student isNo ports to be damaged through frequent useSeparate subnet for security
When to use it
Teaching areas Extending the network to new areas Public areas (library, café) Occasional use Out doors In conjunction with the existing network
How to put computers in teaching
Computer ownership is like literacy90% literate you still have to read everything100% literate changes everything
Putting computers in students’ handsUbiquitous computingComputer carts“loan machines”
Computer cart
Computers at teaching
Computers go to the studentsCurrently students have to go to the computers
All spaces can be used with computersCurrently just computer labs
Computers can be integrated into learningCurrently dominate or are absent
Ubiquitous computing
All students required to have their own computer (Laptop or PDA)Student purchaseLoan machines
Internet enabled everywhere; at all times Fully embedded in education
Recommendations (LANs)
Use wireless LANs To extend existing LANs To provide student access To bring computers to teaching
Use Wi-Fi (802.11b) with upgrade to 8012.11g Do not buy 802.11a until compatibility between
products demonstrated Ensure that security meets institutional needs Perform a site survey Consider the educational benefits from the start Assume that there will be an increase in use in
networked computer use in teaching and learning
Recommendations (WANs)
Consider for connecting remote sites interoperability does not matter as it is point-
to-point Consider wireless and satellite
