Patch Based Mobile Sink
Movement
By
Salman Saeed Khan
Omar Oreifej
Outline
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Introduction
Goals and Expectations
Project Description
Implementation
Results
Simulation
Introduction
Introduction
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Wireless sensor network is an active research area
with numerous applications and different
techniques developed each year
Some Applications
Environmental monitoring
 Battlefield Awareness
 Tracking and Smart Environments
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Introduction
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Patch-based sensor networks is a sensor network
divided into random areas called patches
Patches contain sensors which collect information,
but do not forward them
Several mobile sinks are moving around the field,
visiting patches and collecting information
We discuss a patch based sensor network that is
distributed over a field to collect motion
information about birds passing over the field
Introduction
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Sensors are detecting bird existence
Whenever a bird comes into the transmission
range of a sensor it stores that bird’s information
We have Mobile Sinks so mobility is what matters
Study, analyse and compare different sink
movement models
Different mobile movements achieves:
Different amount of information
 Different utilities of information
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Goals and
Expectations
Goals and Expectations

Exploring the different ways that a sink can visit
randomly distributed patches
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Efficiency of a visiting technique can be represented
by
Amount of collected data
 Power consumption
 Utility of the collected results
 Consistency of the results
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Goals and Expectations
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Real life:
A
combination of all factors should be taken
into consideration when evaluating a visiting
technique

Our project:
 will
only consider the amount and utility of the
collected data
 Utility represented by how new or fresh is that
data
Goals and Expectations

Expectations:
 Simulate
a patch based sensor network using
YAES simulator
 Conduct three different styles of movement for
the sink
 keep a log of all data gathered by each
movement technique
 Analyse the data and conclude the best sink
visiting movement technique
Project Description
Project Description
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In general, Patch based sensor network with
mobile sinks is desired
Easier routing: because of patch heads topology
 Energy Efficient: High rate communications only
occur on patch heads, other normal sensor nodes
would save energy. Moreover, only sinks move in the
field
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Project Description
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Project:
A field of an approximated area of half squared mile
 Simple sensor nodes randomly deployed on the field
 The sensor nodes are static in place and capable of
detection of any bird flying over the sensors and
within its transmission range
 Birds are simulated by actuator agents who are
moving randomly in the field
 Multiple mobile sinks scattered collecting data from
nodes
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Project Description
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Patching
Was implemented virtually
 Each sensor node
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Is a normal sensor: Senses birds existence
 Is a patch head: communicates with the sinks
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Project Description
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Sink movement techniques are the main issue in the
project
All movement models aims at collecting the most data
with the most utility
Introducing three different sink movement techniques
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Random Movement: Sinks are moving around randomly within
the fields range
Regular Movement: Sinks are deployed into a straight line
covering the whole width of the field and they are moving back
and forth along the height of the field
Project Description
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Information Based Movement:
 Sinks
can get information about the amount of data
generated in a patch
 Each sink determines the hottest patch and moves to
collect information from that patch while no other sink
goes there
 After a sink reaches the desired patch it will again search
for the hottest non-reserved patch and head for it
Project Description
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Communications
Occurs when a bird agent comes within the
transmission range of a sensor
 The sensor will store data about the bird by filling a
temporary buffer that each sensor maintains
 When a sink is able to communicate with a sensor
node, the node gives all what it has to the sink and
then flushes its buffer
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All data gathered from all sinks are delivered at
the end to a data storage unit
Challenges and
Problems
Challenges and Problems
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Addition of multiple sinks and their movement in
YAES.
Implementation of Utility of information.
Comparing Results to other experiments
Implementation
Implementation
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Eclipse 3.2 & YAES library
YAES objects used:
 Field
 Sensor Node
 Sink Node
 Actuator Node (Bird)
Field
 Is a Java panel
 Is relative in size to other objects
Implementation
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Sensor Node
 Has a location, name and an agent
Patch Sensor Agent
 Extends AbstractSensorAgent class.
 Can buffer data, can transmit and receive messages
Sink Node
 Extends SensorNode class
 Has a location, name and an agent
Implementation
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Patch Sink Agent
 Extends AbstractSensorAgent class.
 Can buffer data, can transmit and receive messages
Actuator Node
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Used as it is in YAES
Moves randomly
 Announces its location to sensor nodes
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Implementation
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Changes made to YAES library
 Multiple sinks
 Arrangement helper class
Deployment
 Sensors and birds deployed randomly
 Sink deployment dependent on movement type
Communication
 Messages
 Each message has a sender and destination address,
message type and message content
Implementation
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Communication
 Sinks broadcast a message of type “Query”
 Sensor reply with a message of type “Query-Reply”
 Bird location and its utility is stored in a buffer. The
utility of information decreases with each
simulation. The whole buffer is instantaneously
transmitted when replying to the sink
Implementation
Information-based Movement (Algorithm)
 At each simulation step, for each sink
 Assign the hottest available sensor node to the sink if it
has not already been assigned one
 Make this sensor node unavailable to other sinks
 If the distance between the sink and the sensor node is
greater than the transmission range of the sensor node
 Move the sink towards the sensor node
 Otherwise make this sensor node available to other sinks
and free its current assignment
Simulation
Results
Results
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The simulation utility is calculated as follows:
Results
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Comparison between different sink movements is done by
calculating the total utility of information gathered by all sinks in the
simulation plotted against the number of sink nodes.
10 *Logarithm of Total Utility
Number of Sinks
Random Movement
Regular Movement
Information
Movement
1
48.51
53.88
56.25
2
49.84
44.88
58.14
3
51.25
52.46
59.27
4
55.58
55.63
58.20
5
56.00
55.28
59.61
6
56.93
56.61
59.09
7
57.52
58.75
59.84
8
57.17
54.54
60.59
9
58.10
58.71
60.52
10
57.75
58.98
60.81
Based
Results
Utility Vs Number of Sinks
10Log(Total Utility)
65
60
55
Random
Regualr
Information Based
50
45
40
1
2
3
4
5
6
7
Number of sinks
8
9
10
Future Work
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Patch generation and patch leader selection and
communication.
Sink movements
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Distance, Hotness, Remaining Energy (Optimization
problem)
Probabilistic etc.
Comparison of sink movement techniques and results
to other suggested papers.
Implementing a power consumption function for the
sinks
Introducing packet loss over network based on signal
strength and noise.
Thank You