Albert Huang ([e-mail])

1
An Infrastructure for Location Aware Computing

• Albert Huang (albert_at_csail.mit.edu)
• Larry Rudolph (rudolph_at_csail.mit.edu)

2
Location Aware Computing

• Briefly describe lac, its uses and applications
• GPS

3
Important things

• Cost
• Should not be prohibitively expensive
• Accuracy
• Room-level granularity
• Privacy
• Should protect privacy of users
• Ease of deployment
• Should be easy to deploy

4
Other technologies

• IrDA
• Directional, need line-of-sight, flaky
• 802.11b
• Too coarse-grained, high power, but has potential
• RFID
• Expensive readers. Coarse-grained.
• RF/ultrasound (Cricket, Active Bat)
• Much more precise, but expensive

5
Bluetooth

1. Short range wireless communication specification
2. Stable, inexpensive, mature
3. Ubiquitous (almost)

6
Positioning with bluetooth
Hello!
Hello? Anybody there?
Hello!
Hello!
7
Privacy

• Device inquiry does not reveal identity
• Responding to a device inquiry, and higher-level
  connections do
• Limiting locator to inquiries preserves anonymity

8
Signal Strength

• Inversely related to distance
• Should help accuracy
• Not widely supported, vendor specific
• D-Link USB does
• HP iPAQ does not
• Nokia does, with NDA

9
Security

• Non-existant
• But it doesnt matter!

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iPAQ Locator
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Stata Navigation
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Stata Navigation
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Stata Navigation
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Some Issues

• Effectiveness
• Maintenance