Toward efficient task management in wireless sensor networks

1. VISVESVARAYA TECHNOLOGICAL UNIVERSITY
Jnana Sangama, Belgaum, Karnataka-590 014.
A Seminar On
“Toward Efficient Task Management in Wireless Sensor Networks”
By Guide
NAVEENA N Prof. PANDURANGA RAO
(Professor of CSE department)
B.T.L INSTITUTE OF TECHNOLOGY
Department of Computer Science & Engineering
2012-13

2. A G E N D A
oAbstract
oTask Management in Wireless Sensor Networks
oExisting system
oProposed System
oDrawbacks
oApplications
oConclusion

3.  In numerous applications of wireless
sensor networks (WSN), the reliability
of the data collected by sensors is cast
as specific QoS requirements expressed
in terms of the minimum number of
sensors needed to perform various tasks.
 Challenging due to the modest
nonrenewable energy budget of
individual sensors.
A B S T R A C T

4.  In such a context, energy-unaware task
management protocols may result in
uneven expenditure of sensor energy by
assigning uneven workloads to sensors.
 This, in turn, often translates into
reduced sensor density around those
heavily loaded sensors and may,
eventually, lead to the creation of
energy holes that partition the network
into disconnected islands.
A B S T R A C T

5.  To avoid these problems and to
promote network longevity, we
propose two energy-aware task
management protocols.
 Our first protocol is centralized, while
the second one is fully distributed.
The proposed protocols assign tasks
to sensors based on their remaining
energy so that energy expenditure
among neighboring sensors is almost
even.
A B S T R A C T

6. Task Management in Wireless Sensor Networks are constituted by
 sensor nodes, also known as motes or simply nodes are small and
energy constrained devices that have the ability of sensing the
surrounding environment.
 The sink, also known as base station, is a more powerful node that
behaves as an interface between the sensor nodes and the clients.
 In many WSN applications, the sensors will provide information
in response to queries or tasks assigned to them by task-issuing
entities (TIEs) placed.
 A task starts when the TIE sends a sequence of Call To Work
(CTW) messages to get the attention of a sufficiently large
number of sensors that we will refer to as “candidate sensors.”
Task Management in Wireless sensor Networks

7.  An example of improper task assignment.
 sensing range of sensors is R.
 Two tasks T1 and T2.
 sensors S1 through S9.

8.  In existing model proposed a centralized task management and
workforce selection protocol for special purpose single hop
sensor-based mission critical networks.
 The proposed protocol was used to recruit sensors that reside within
a disc centered at the current location of the TIE.
 A major drawback of the previous protocol, it can only recruit
sensors that lie within a single hop from each other and also from
the TIE.
 After a certain point, some sensors within the same cell will not be
within the communication range of each other, hence the work-
force selection protocol cannot be used.
Existing system

9.  First, we develop a tasking model that is appropriate for the
alternating wake up/sleep duty cycles inherent to sensor design.
 On top of this model, we propose two workforce selection
protocols for sensor networks,
 First protocol is centralized while the other is distributed.
 The new protocols do not have the single-hop restriction we had
in the previous protocols. Hence, they can be used to recruit
sensors anywhere in the network.
Proposed system

10.  The distributed protocol has the advantage of reducing the
overhead imposed on any central nodes selected to be
responsible for the co-ordination of the workforce selection
process.
Proposed system(contd)

11.  Tasking model in the centralized protocol

12. CTW Messages

13.  Tasking model for the distributed protocol.

14.  Estimating the maximum energy among
candidate sensors

15.  Dividing the sensing range into k disjoint
regions.

16. Advantages
 It avoids data spoofing.
 It avoids privacy leakage.
 Minimize communication and computational cost.
 Maximizes the battery power by preserve the power of
Underwater sensors.

17.  Schemes is challenging because they do
not work well in mobile environments.
 Routing is specially challenging in wsn’s
due to the large propagation delays, low
bandwidth, difficulty of battery refills of
underwater sensors, and dynamic
topologies
Drawbacks

18. A P P L I C A T I O N S
 Search and rescue missions

19. A P P L I C A T I O N S
 General maintenance

20. A P P L I C A T I O N S
 Fleet management services

21.  Wireless technology will play a vital role in many
application areas that are not possible in the past. Wireless
Underwater communication would be one of them.
 proposed protocols can increase the reliable lifetime of the
network by evenly consuming sensors energy and reducing
energy differences between sensors within the same sensing
area.
 Currently, we are trying to extend this work by adjusting
sensor-sleeping time based on the relative difference
between sensor remaining energy and the energy of other
surrounding sensors.
C O N C L U S I O N

22. Thank you…!!!