1. 6.4 Global Positioning of Nodes
Boyu(Michael) Hou

2. Overview
Introduction
Fundamentals
Current work
Further work

3. Introduction Position Event Data transmission Efficiency Network load
Etc.

4. Fundamentals Distributed system Distributed algorithm
Global positioning of nodes
Tracking system
Nodes growth
Distributed algorithm
Routing
Multicasting
Searching

5. Fundamentals Distance corresponds to internode latency
Distance reflects how long it would take for a message to travel between two nodes
Positioning a node in an m-dimensional geometric space requires m+1 distance measures to nodes with known positions

6. Fundamentals
Issues
Internet latency measurements may violate the triangle of inequality.
Node distance affects accuracy
Geography environment influence
Impossible to resolve inconsistencies completely.

7. Current work Algorithm Range based Range free AHLos RADAR Centroid
Distance Vector Hop
APIT
MAP

8. Current work Node position: Range based measurement: Range free:
in a sensor network when some of the position information is known, the position of other sensor nodes can be estimated using measurement and position estimation
Range free:
takes advantage of network connectivity or topology to estimate the distance, and then uses the trilateration or maximum likelihood to estimate the position.

9. Current work Distance Measurement Methods TOA (Time of Arrival)
TDOA (Time Differential of Arrival)
AOA (Angle of Arrival)
RSS (Received Sinnal Strength)

10. Further work
Improved algorithms for distance measurement and position estimation
Extend distance measurement model to three-dimensional
Accuracy
Efficiency
Applying node positioning to real world applications
Animal tracking and protection
Adventure

11. Thank You