Title: Techniques for Improving Opportunistic Sensor Networking Performance
1Techniques for Improving Opportunistic Sensor
Networking Performance
- Shane Eisenman Nic Lane, Andrew
Campbell
Columbia University
Dartmouth College
2Large-scale Sensing requires...
3Application Query Assignment (i.e., Tasking)
Local Tasking
4Application Query Assignment
Remote Tasking
Internet
RAN 1
Sensing Query
RAN 2
John Q. Public
5I have the query. Now what?
- Query Sensor type,
- target location,
- sensing deadline, ...
No sensor --gt ?
6Improving Success Probability
- Sensor Sharing
- Sensor Substitution
7Modeling Query Success Probability
- P(success) P(reaching tasking point)
-
- x P(reaching
target) - x
P(having right sensor) -
- ...before the sensing deadline.
8N x N grid representation of a neighborhood
9Torus Topology (N10)
Move N,E,S,W
10Campus Topology (N10)
Move according to real-world connectivity
11Results
- Randomly assign sensors to mobile nodes
- (20 choose r)
- Calculate the sensing success probability for
various values of number of nodes, number of
sensors per node, and sensing deadline
12Comparing Campus and Torus
Fixed num sensor types3.
The topology of the campus limits node mobility,
requiring a longer deadline to reach the same
success probability.
13Comparing Campus and Torus
Fixed sensing deadline50.
Qualitative trends are very similar between Torus
and Campus, despite the very different mobility
patterns.
14Sensor Sharing
P(success) P(reaching tasking point)
x P(reaching target)
x ( P(having right sensor)
P(sensor
sharing) ) ...before the sensing deadline.
15Benefit of Sensor Sharing
Fixed num sensor types3.
Sharing improves success probability up to 16.
As the deadline increases the improvement
diminishes.
16Benefit of Sensor Sharing
Fixed sensing deadline50.
Sharing improves success probability up to 70.
Increasing number of sensor types decreases
possible improvement.
17Sensor Substitution
P(success) P(reaching tasking point)
x P(reaching target)
x ( P(having right sensor)
P(sensor
substitution) ) ...before the sensing deadline.
18Benefit of Sensor Substitution
Fixed num sensor types3. Fixed num mobile
sensors20.
Substitution improves success probability up to
155. Increasing deadline decreases possible
improvement.
19Benefit of Sensor Substitution
Fixed sensing deadline50. Fixed substitution
prob0.02.
Substitution improves success probability up to
36. Increasing num. sensor types decreases
improvement.
20Combined Sharing and Substitution
P(success) P(reaching tasking point)
x P(reaching target)
x ( P(having right sensor)
P(sensor
sharing)
P(sensor substitution)) ...before the sensing
deadline.
21Combined Sharing and Substitution
Fixed num sensor types3. Fixed num mobile
sensors20.
Up to 270 gains in success probability
(sharing-only 16, substitution-only 160 with
same parameterization).
22Combined Sharing and Substitution
Fixed sensing deadline50. Fixed substitution
prob0.02.
Up to 140 gains in success probability
(sharing-only 70, substitution-only 35 with
same parameterization).
23Summary
- Opportunistic people-centric sensing is the
future for very large-scale sensing. - Sensor Sharing and Sensor Substitution are
composable techniques to increase the probability
of query success. - Help to provide a level of abstraction between
locally sensing resources and application
requirements.
24For more information...
- http//METROSENSE.cs.dartmouth.edu