The Cricket Location Support System - People

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  • 1.The Cricket Location-Support System By: Min Chen 10/28/03
  • 2.Goal User Privacy Decentralized administration Network heterogeneity Low cost Room-sized granularity
  • 3.System Architecture Beacon: Disseminate the string of space information about a geographic space to listeners. Listener: Infer its current location from the set of beacons . Use combination of RF and ultrasound to provide a location-support service to users. Approach
  • 4.Related Problem and Method Collision of RF transmissions from different beacons ------------Randomization Wrong correlation of the RF data of one beacon with the ultrasonic signal of another ------ System parameters ------ Listener Inference Algorithms
  • 5.use a relatively sluggish RF data transmission rate. System Parameters Selection
  • 6.Interference Scenarios RF-A:US-RA Align the beacons RF-A:US-I Using RF signal with long range RF-A:US-RI Ensure less than 5 beacons within range of each other
  • 7.Listener Inference Algorithm Majority Picks the beacon with highest frequency of occurrence MinMean Selects the beacon with the minimum mean value MinMode Compute the per-beacon statistical mode over the past n samples.
  • 8.Implementation :Beacon Positioning and Configuration
  • 9.Implementation :Ultrasound Deployment
  • 10.Experiment: Boundary Performance
  • 11.Experiment: Static Performance
  • 12.Experiment: Static Performance (Cont)
  • 13.Experiment: Mobile Performance
  • 14.Comments Concerns when apply to sensor network 2D Constrain Power Consideration Calibration On the Transmitter. Kalman Filter for the Mobile Algorithm