The document summarizes Shiwangi Yadav's mid-semester presentation on data aggregation in wireless sensor networks. It discusses wireless sensor networks and defines data aggregation. It describes the main goal of data aggregation in WSNs as gathering and aggregating data in an energy efficient manner to enhance network lifetime. It then outlines four common strategies for data aggregation - centralized approach, in-network aggregation, tree-based approach, and cluster-based approach. For each approach it provides a brief description and discusses advantages and disadvantages. The presentation concludes with discussing future plans to further investigate issues of data aggregation related to redundancy elimination, delay, accuracy, and traffic load.

1. Mid Semester Presentation
Seminar-I
On
Data Aggregation in Wireless Sensor Network
Presented by
Shiwangi Yadav
M.Tech(C.S.E), 3rd Semester
Under the supervision of
Mr.Nileshkumar Patel

2. Content
 INTRODUCTION
 Wireless Sensor Network
 Data Aggregation
 Data Aggregation in WSN
 Use of Data Aggregation in WSN
 Advantages and Disadvantages
 DATAAGGREGATION STRATEGIES
 Centralized Approach
 In-Network Aggregation
 Tree-Based Approach
 Cluster-Based Approach
 CONCLUSIONS
 FUTURE PLAN
 REFRENCES

3. Wireless Sensor Network
• WSN is a wireless network consisting of spatially
distributed autonomous devices using sensor to
monitor physical or environmental conditions.
• In WSN sensor nodes are deployed in a region to
sense the information [3].

4. Data Aggregation
• Aggregation can be simply defined as “the ability to
summarize information” [1].
• Data aggregation is a process in which intermediate
node receives multiple input packets perform
aggregation and produce single output packet in the
network [2].

5. Data aggregation in WSN
• Data aggregation usually involves the integration of
data many sensor nodes and the aggregator data to
the base station [1].
• The main goal of data aggregation is to gather and
aggregate data in an energy efficient manner so that
network lifetime is enhanced [2].

6. Use of data aggregation in WSN
• We need method for combining data into high-quality
information at the sensors or intermediate nodes
which can reduce the number of packets transmitted
to the base station resulting in conservation of energy
and bandwidth [5].
• Data aggregation technique removes data redundancy
from wireless sensor network in order to enhance the
lifetime of WSN [2].

7. Advantages
• Enhance robustness and accuracy of information.
• Reduce traffic load and conserve energy of sensors.

8. Disadvantages
• Malicious attacker.
• Cannot ensure correctness.
• Increase power consumption.

9. Data Aggregation Strategies
There are four strategies for data aggregation [2]:
• Centralized Approach
• In-Network Aggregation
• Tree-Based Approach
• Cluster-Based Approach

10. Centralized Approach
• In this approach each node sends data to a central node
via the shortest possible route.
• All the sensor nodes simply sends the data packets to a
node, which is the powerful among all other nodes [2].
Figure1. Centralized approach

11. Pros and Cons
• Pros:-
i. Simple in nature.
ii. It extends the network lifetime.
• Cons:-
i. It cannot be used for continuous data delivery [4].

12. In-Network Aggregation
• The aggregation is the global process of gathering
and routing information through a multi-hop
network and processing data at intermediate nodes
with the objective of reducing power consumption.
• There are two types of approach in-network
aggregation: with size reduction and without size
reduction [2].

13. • With size reduction: It refers to the process of
combining and compressing the data packets
received by a node from its neighbors in order to
reduce the packet length that is to be transmitted or
forwarded towards sink [2].
Figure2.With size reduction

14. • Without size reduction: In-network aggregation
without size reduction refers to the process merging
data packets received from different neighbors into a
single data packet but without processing the value of
data [2].
Figure3. Without size reduction

15. Pros and Cons
• Pros:-
I. Data security,Low energy.
• Cons:-
I. Not applicable for large network [4].

16. Tree-Based Approach
• In the tree based approach at first data integration tree
is formed.
• For each data transmission minimum spanning tree is
created.
• Each node has a parent node to forward its data [2].
Figure4. Tree based approach

17. Pros and Cons
• Pros:-
I. Ability to tolerate disconnections and loss.
• Cons:-
I. Network lifetime is limited [4].

18. Cluster-Based Approach
• In Cluster-Based Approach, whole network is
divided into several clusters. Each clusters is
consisting of many sensor nodes [2].
Figure5.Cluster based approach

19. Pros and Cons
• Pros:-
I. Low energy, increased lifetime of network.
II. Improved energy efficiency.
• Cons:-
I. It is not used for large network region.
II. Lifetime of sensor node is limited [4].

20. Conclusion
• In this seminar, data aggregation in WSN has been
investigated focusing on various data aggregation
strategies.
• In particular, data aggregation is introduced
considering definition and its pros and cons and a
comparative study.
• A detail insight of data aggregation is presented
consists of the various strategies of data aggregation.
• With the help of different data aggregation techniques
it is possible to reduce energy consumption.

21. Future Plan
In future various issues of data aggregation will be
investigated in detail.
• Redundancy Elimination
• Delay
• Accuracy
• Traffic load

22. Reference
[1]Priyanka B. Gaikwad, Manisha R. Dhage, “Survey on
secure data aggregation in wireless sensor
network,”International Conference on Computing
Communication Control and Automation, 978-1-4799-
6892-3/15 © 2015 IEEE.
[2] Sumedha Sirsikar, Samarth Anavatti, “Issues of Data
Aggregation In Wireless sensor network: A survey,” 4th
International Conference on Advances in Computing,
Communication and Control (ICAC3’15) 1877-0509 ©
2015 Elsevier.
[3]Xiang Yang Li, Wireless Ad Hoc and Sensor Networks,
CAMBRIDGE UNIVERSITY PRESS, New York, 2008

23. [4]V. Priya Ujawe,Simran Khiani, “Review on Data
Aggregation Techniques for Energy Efficiency in
Wireless Sensor Network,” ISSN 2250-2459, ISO
9001:2008 Certified Journal, Vol. 4, Issue 7, July
2014.
[5]M. R Rashmi, “Analysis Of Data Aggregation In
Wireless Sensor Network,” International Journal of
Applied Engineering Research and Development
ISSN(P): 2250-1584; ISSN(E): 2278-9383 Vol. 4,
Issue 1, Feb 2014.

24. Thank you…