kais t a bidding protocol for deploying mobile sensors 발표자 : 권 영 진 guiling wang, guohong...
TRANSCRIPT
KAIST
A Bidding Protocol for Deploying Mobile SensorsA Bidding Protocol for Deploying Mobile Sensors
발표자 : 권 영 진
Guiling Wang, Guohong Cao, Tom LaPorta
The Pennsylvania State UniversityIEEE, ICNP 03
ContentsContents
Introduction
Voronoi diagram
Bidding protocol(key concepts, remained issues)
Performance evaluations
Conclusion
22 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Introduction ( 1/2 )Introduction ( 1/2 )
Mobile sensor
Problems : How to deploy mobile sensors efficiently?“Three distributed self-deployment protocols”
(Movement-Assisted Sensor Deployment, IEEE infocom 04)
Use only mobile sensor
Not cost-effective
33 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Introduction ( 2/2 )Introduction ( 2/2 )
“Bidding protocol”Key idea : static sensor + mobile sensor
Coverage holes : the area that sensor cannot cover
Static sensor : detection of coverage holes
Mobile sensor : heal of coverage holes
44 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Sensor circle
Coverage holes
Static sensor
Mobile sensor
Hole healing
Terminologies of Voronoi diagramTerminologies of Voronoi diagram
55 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Voronoi cell
Voronoi diagram
Applying Voronoi diagram to Mobile Applying Voronoi diagram to Mobile sensorsensor
Put sensor on site points
Each sensor is responsible for the sensing task in Voronoi cells
Each sensor can examine the coverage hole locally
66 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
sensor
Bidding protocol ( key concepts) ( Bidding protocol ( key concepts) ( 1/7 )1/7 )
Important questionsHow to estimate coverage hole?
Which mobile sensor should move to the place?
Where should the mobile sensor move?
Bid ( for static sensor ) estimated size of hole
Base price ( for mobile sensor ) estimate of generated coverage hole after it leaves
the current place
77 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Bid Estimation( in Static Sensor )Farthest Voronoi vertex is the target location of mobile sensor
Bid is the area of the inner circle
88 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Bidding protocol ( key concepts) ( Bidding protocol ( key concepts) ( 2/7 )2/7 )
Healing of most largest hole
d
Bid = π * ( d – sensing_range)2
relative size of coverage hole
Bidding protocol ( key concepts) ( Bidding protocol ( key concepts) ( 3/7 )3/7 )
Base price evaluation( in mobile sensor )Initial value is 0
The accepted bid is a new base price
Meaning of a bid and a base price
99 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Bid: estimate of healed hole
Base price : estimate of upcoming hole
Bidding protocol ( key concepts) Bidding protocol ( key concepts) ( 4/7 )( 4/7 )
1010 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Let’s put it all together !
Bidding protocol flows( round by round )
Service advertisement
Initialization
Serving
Bidding
Termination
Construct Voronoi diagram
Bidding protocol ( key concepts) Bidding protocol ( key concepts) ( 5/7 )( 5/7 )
Service advertisementMobile sensor broadcasts their base price and location
Base price is set to zero initially
BiddingCalculate bids and target location for the mobile sensor
Send bids to closest mobile sensor
whose base price is lower than bids
1111 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Bidding protocol ( key concepts)Bidding protocol ( key concepts) ( 6/7 ) ( 6/7 )
ServingMobile sensor choose the highest bids and heal coverage holes
Accepted bids becomes new base price
TerminationIf base price of all mobile sensor is higher than bids, then terminate
1212 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Bidding protocol ( key concepts)Bidding protocol ( key concepts) ( 7/7 ) ( 7/7 )
1313 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Mobile sensorStatic sensor
93% coverage at round 5
40 sensors, 12 mobile sensors
82% coverage
Performance evaluations ( 1/3 )Performance evaluations ( 1/3 )
Evaluation methodologyMain cost
Number of sensor
Number of round
EnvironmentNs-2 simulator
40 sensors and 10 independent experiments
Some considerationsTrade off between cost and coverage
Cost ratio between the mobile sensor and the static sensor
1414 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Performance evaluations ( 2/3 )Performance evaluations ( 2/3 )
1515 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
Random deployment : just use static sensorBidding protocol : static sensor + mobile sensorVEC algorithm : mobile sensor
Random deployment
Bidding protocol
VEC algorithm
Trade off The more mobile sensor are used, The better coverage is obtained But the sensor cost will be increased
Performance evaluations ( 3/3 )Performance evaluations ( 3/3 )
1616 / 17 / 17A Bidding Protocol for Deploying Mobile Sensors
ConclusionsConclusions
Voronoi diagram can be applied to a sensor network
using a greedy heuristic method
Mixture of a static sensor and a mobile sensor can achieve
a good balance between coverage and cost
1717 / / 1717A Bidding Protocol for Deploying Mobile Sensors
Extra ( 1/4 ) Extra ( 1/4 )
Duplicate healing
18 / 1718 / 17A Bidding Protocol for Deploying Mobile Sensors
Extra ( 2/4 ) Extra ( 2/4 )
Duplicate healing detection
19 / 1719 / 17A Bidding Protocol for Deploying Mobile Sensors
A
B
Broadcast
Check if base price of A > base price of BIf yes, run detection algorithmIf detected, set base price of A to zero
Extra ( 3/4 ) Extra ( 3/4 )
Detection AlgorithmDetecting threshold = π * ( dmin – sensing_range)2
dmin : Distance to closest neighbor
IF ( detecting threshold < new base price ||
dmin < sensing_range )
THEN duplication occurs
20 / 1720 / 17A Bidding Protocol for Deploying Mobile Sensors
Extra ( 4/4 )Extra ( 4/4 )
21 / 1721 / 17A Bidding Protocol for Deploying Mobile Sensors
A,B is mobile sensor
Snapshot in the middle of round
Nf ’s base price is calculated without consideration of Ne
at Nf
Detecting threshold < New base price
New base price of B
dmin
Why Detecting threshold < New base price?