Location Service for Mobile Device
1
A CS395T Course Project Mobile Computing & Wireless Networks Spring 2001 C o u r s e w e b s i t e : h t t p : / / w w w . c s . u t e x a s . e d u / u s e r s / y g z / 3 9 5 T • I n s t r u c t o r : D r . Y o n g g u a n g Z h a n g ( y g z @ c s . u t e x a s . e d u ) Key Design/Approach Data collation: mapping the service area in advance for an accurate signal map Algorithm 1: best matching: O(n 2 ) Algorithm 2: multidimensional search O(log(n)) GUI (see above) Limitation : Placement of Base stations limited to certain locations New Ideas Increasing proliferation of 802.11 base stations and PC card use 802.11 wireless LAN infrastructure to determine mobile device location inside building Signal strength can be measured and there is a correlation between signal strength and distance Signal strengths from multiple base stations can triangulate the exact location Location Service for Mobile Device Results/Lesson Learned Implemented in Linux Tested in ACES 6 th floor –Beacon stations: 2 –Service granularity: 10 feet Accuracy: 90% of the time: within 15 feet Lesson learned: –802.11 Linux driver does not support “promiscuous” mode to pick up beacons from multiple base stations –Resolved to ad-hoc mode Project team: Ravishankar Chamarajnagar, Jeff Napper URL: http://www.cs.utexas.edu/users/ravshank/mobile_project/project.html
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Location Service for Mobile Device. New Ideas Increasing proliferation of 802.11 base stations and PC card use 802.11 wireless LAN infrastructure to determine mobile device location inside building - PowerPoint PPT Presentation
Transcript of Location Service for Mobile Device
A CS395T Course Project MobileComputing &
WirelessNetworks
Spring 2001C
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Key Design/Approach Data collation: mapping the service area in
advance for an accurate signal map Algorithm 1: best matching: O(n2) Algorithm 2: multidimensional search
O(log(n)) GUI (see above) Limitation : Placement of Base stations
limited to certain locations
New Ideas Increasing proliferation of 802.11 base
stations and PC card use 802.11 wireless LAN infrastructure to determine mobile device location inside building
Signal strength can be measured and there is a correlation between signal strength and distance
Signal strengths from multiple base stations can triangulate the exact location
Location Service for Mobile Device
Results/Lesson Learned Implemented in Linux Tested in ACES 6th floor
–Beacon stations: 2–Service granularity: 10 feet
Accuracy: 90% of the time: within 15 feet Lesson learned:
–802.11 Linux driver does not support “promiscuous” mode to pick up beacons from multiple base stations
–Resolved to ad-hoc mode
Project team: Ravishankar Chamarajnagar, Jeff NapperURL: http://www.cs.utexas.edu/users/ravshank/mobile_project/project.html
