1. Graduate Project Presentation
TCET.797.01
Presented By – Braj Raj Singh
Telecommunication Engineering Technology
Efficient Data Aggregation from polling points
in Wireless Sensor Network

2. Background-
Existing System-
A number of approaches exploiting sink mobility for data collection in wireless sensor
networks have been proposed in recent years.
• In single hop communication, we can minimize energy consumption, however, at the
expense of high data delivery delay.
• In the second solution, this delay is low but the energy consumption due to multi hop
communication is rather high.
Proposed System-
Our proposed protocol aims at minimizing the overall network overhead and energy
expenditure associated with the multi hop data retrieval process while also ensuring
balanced energy consumption among sensor nodes and prolonged network lifetime. This is
achieved through building cluster structures consisted of member nodes that route their
measured data to their assigned cluster head (CH).
Clustering has proven to be an effective approach for organizing the network in the above
context. Besides achieving energy efficiency, clustering also reduces channel contention and
packet collisions, resulting in improved network throughput under high load.

3. WIRELESS SENSOR NETWORK
(WSN)
1

4. Wireless Sensor Network
A Collection of Spatially Distributed Organized autonomous sensor nodes that
collects data from its surrounding.
The Wireless sensor network is a combination of wireless sensing and data
networking that consists of protocols and algorithms with self-organizing
capabilities and can be used in safety-critical or highly reliable applications
Important Characteristics-
• Scalability and Reliability
• Self-Configurability
• Flexible Topology Changes
• Self-organized
• No wired infrastructure
• Potential multi-hop routes
• Ability to withstand in harsh environmental conditional

5. Applications of WSN-
 The Military
Applications
 The Medical
Applications
 Environmental
Monitoring
 Target tracking
 Industrial
Application
 Infrastructure
and protection
application

6. Topology of Wireless Sensor Network
• Point to point (Peer to Peer) topology- In this type of network
topology nodes are involved in direct node-to-node communication
without going through centralized communication hub. Each peer is
able to work as either client or server.
• Star topology- In star topology, each node must communicate
through a centralized connected hub. Information cannot be directly
routed through node-to-node .The centralized hub works as server
and connecting nodes works as clients.
• Tree based topology- In a tree based topology, the centralized node
functions as root node. A root node has a central hub that is one step
down in hierarchy. This lower level then forms a star based network,
which is why a tree network is also called hybrid network.
• Meshed Network topology- Mesh networks have a self-healing
property because it allows data to hop from node to node. This type
of network is very complex as compared to other topologies and is
more cost effective.

7. Architecture of Wireless Sensor Network
Wireless sensor network composed of two distinct layers
• Sensor and Networking layers
• Distributed Service layer
Key component of Sensor Network-
1. Sensor Nodes (SN)
2. Cluster Head (CH)
3. Mobile Collector (MS)
4. Rendezvous Nodes /Polling Points
5. Base Station

8. 1.Sensor Node
 Processing Unit
(microcontroller/microprocessor)
 Sensing Unit (A/D convertor)
 Power supply (battery)
 Communication Unit (radio trans-receiver)
Power Supply
Microcontroller
Analog to
Digital
Convertor
S1 S2
External
Memory
Trans
receiver

9. 2. Cluster Head ( CH)
In wireless sensor network, small group of sensor node formed a cluster and each cluster has
a coordinator referred Cluster head (CH). Cluster head selection has impact on network
lifetime. Cluster Head should be reachable in a single hop from their cluster members.
Primary function of Cluster head –
 Aggregate data from respective sensor
node and transferred to remote
processing element.
 Localization of network traffic.
 CH implement network management
strategy to enhance network operation
and prolong the battery life.
 Reduce the rate of energy
consumption by schedule activity
activities in the cluster so sensor node
can switch to low power sleep mode

10. 3. Mobile collector
Mobile Collector
Data Collector (Sink) can be classified in two category-
Static Collector- Network sink nodes are on fixed
position; either close or inside the sensing region that
makes network simpler to control.
Mobile Collector-The Mobile Collector (MC) moving
through the network deployment region can collect
data from the static sensor nodes over a single hop
radio link when approaching within the radio range of
the sensor nodes or with limited hop transfers if the
sensor nodes are located further.
Mobility pattern of Data collector-
a) Random
b) Predictable (their movement pattern is known before hand)
c) Controlled (their movement is actively controlled in real time)

11. 4. Polling Points /Rendezvous Nodes-
• Polling points guarantee connectivity of sensor clusters with Mobile collector. Their
selection largely determines network lifetime.
• Polling points are selected among candidate Sensor node typically located in the
periphery of the sensor island and lie within the range of mobile collector.
• Suitable polling points are those that remain within the Mobile collector range for
• relatively long time, in relatively short distance from the sink's trajectory and have
sufficient energy supplies.
Polling Point
Sink
Trajectory

12. 5. Base Station
The base stations are one or more components of the WSN with more computational
energy and communication resources. They act as a gateway between sensor nodes
and the end user as they typically forward data from the wireless sensor network on
to a server.

13. CLUSTERING MECHANISM2

14. Clustering
Clustering is a process of logical grouping of similar sensors to achieve load balancing and
network scalability . Clustering is an effective approach for organizing the network that
reduces channel contention, packet collision and improved network throughput under high
load.
Cluster
Head
Mobile
Sink
Data Aggrega on
Cluster Head Elec on
Cluster Forma on
Sensor
Nodes
Sensory
Data
Cluster forma on and Data Collec on approach by Mobile Sink from Sensor Nodes

15. Clustering Objectives
 Support Network Scalability
 Decrease energy consumption through data aggregation
 Limits data transmission (load balancing)
 Facilitate the reusability of the resources
 Conserve communication bandwidth
 Cluster Head and gateway nodes can form a virtual backbone for inter-
cluster routing
 Cluster structure gives the impression of a smaller and more stable
network
 Improve network lifetime
 Reduce network traffic and the contention for the channel
 Data aggregation and updates take place in CHs

16. Types of Clustering

17. Cluster Communication
Clustering support network scalability and reduces energy consumption through efficient
data aggregation. It can localize the route setup with in the cluster and thus reduce the size of
routing table that help to stabilize network topology.
Cluster communication can be classified as-
CH
CH
CH
Base Sta on
Intra-cluster
Inter-cluster

18. Base Sta on
Sensor Nodes Deployed in a Region
Sensor informa on forwarding without clustering –Single hop Mechanism

19. Base Sta on
Sensor Nodes Deployed in a Region
Sensor informa on forwarding without clustering –Mul -hop Mechanism
Sensor Nodes

20. Base Sta on
Sensor Nodes Deployed in a Region
Sensor informa on forwarding with clustering –Single hop Mechanism
Cluster Forma on
Cluster Head
Sensor Nodes

21. Base Sta on
Sensor Nodes Deployed in a Region
Sensor informa on forwarding with clustering –Mul -hop Mechanism
Cluster Forma on
Cluster Head
Sensor Nodes

22. ROUTING3

23. Routing
Routing has two main function- Route Discovery and Packet forwarding .
The major requirements of a routing protocol-
• Minimum route acquisition delay
• Quick route reconfiguration in the case of path breaks.
• Loop-free routing
• Distributed routing protocol
• Low control over-head
• Scalability with network size
• QoS support as demanded by the application
• Support of time-sensitive traffic and
• Security and privacy

24. Types of Routing -
Rou ng Protocol
Flat Hierarchic
Proac ve Reac ve
DSDV AODV/DSR

25. Proactive Vs. Reactive-
Proactive (Table Driven) Reactive (On- Demand)
Route from each node to every other node in
the network
Routes from Source to Destination only
Routes are ready to use instantaneously Routes constructed when needed, higher
connection setup delay
Periodic route-update packets Route update when necessary
Changes to network topology immediately
propagated
Changes to network topology not propagated
immediately
Large routing tables Small or No routing tables

26. AODV Routing Protocol
Reactive or on Demand
Uses bi-directional links
Route discovery cycle used for route based on
requirement
Sequence numbers used for loop prevention and as route
freshness criteria
Provides unicast and multicast communication
Maintain Active routes.
Whenever routes are not used -> get expired->Discarded
– Reduces stale routes
– Reduces need for route maintenance

27. AODV Routing Table
In AODV each node maintain a routing table this routing table contains information about
reaching destination nodes .The routing table field includes- Destination IP address,
destination sequence number, valid destination sequence number flag, Network interface,
hop count, next hop, precursor list and life time which is normally route expiration or
deletion time

28. AODV Route Discovery Mechanism
In AODV protocol when a node willing to send a packet to some Destination .It checks its
routing table to determine if it has a current route to the destination-
• If Yes, forwards the packet to next hop node
• If No, it initiates a route discovery process
❒ Route discovery process begins with the creation of a Route Request (RREQ) packet ->
source node
RREQ- route request-
RREQ contain most recent sequence number of the destination. RREQ is broadcasted when
a node needs to discover a route to its destination. As this message propagate through a
network intermediate nodes use it to update their routing table.
❒ Packet also contains broadcast ID number, Broadcast ID gets incremented each time a
source node uses RREQ
• Broadcast ID and source IP address form a unique identifier for the RREQ
❒ Broadcasting is done via Flooding

29. Route Request Propagation ( RREQ)

30. Propagation of Route Reply (RREP) message-
When a RREQ reaches a destination node the destination route is made available by Unicast a
RREP back to the source route. A node generate RREP if it has an active route to destination.
As RREP propagate back to the source node, intermediate nodes update their routing table.

31. Route Error Message ( RERR)-
RERR is initiated by the node upstream (closer to the source) of the break
• Its propagated to all the affected destinations
• RERR lists all the nodes affected by the link failure -> Nodes that were using the link to
route messages (precursor nodes)
• When a node receives an RERR, it marks its route to the destination as invalid -> Setting
distance to the destination as infinity in the route table
❒ When a source node receives an RRER, it can reinitiate the route discovery
1. Link between C and D breaks
2. Node C invalidates route to D in
route table
3. Node C creates Route Error
message
• Lists all destinations that are now
unreachable
• Sends to upstream neighbors

32. Route Maintenance Mechanism-
Node A receives RERR
• Checks whether C is its next hop on
route to D
• Deletes route to D (makes distance -
> infinity)
• Forwards RERR to S
Node S receives RERR
• Checks whether A is its next hop
on route to D
• Deletes route to D
• Rediscovers route if still needed

33. Importance of Sequence Number -
Sequence numbers used for route freshness and loop prevention
To prevent formation of loops
• A had a route to D initially
• Assume that A does not know about failure of
link C-D
because RERR sent by C is lost
Now C performs a route discovery for D. Node A
receives the RREQ (say, via path C-E-A)
• Node A will reply since A knows a route to D
via node B
• Results in a loop (for instance, C-E-A-B-C )
Loop C-E-A-B-C
Because of usage of sequence number, A
will not use the route A-B-C, because the
sequence numbers will be lower than what A
receives from A

34. DSDV Routing Protocol
 The DSDV routing protocol is an enhanced version of the distributed Bellman-Ford
algorithm where each node maintain a table that contain the shortest distance and
the first node on the shortest path to every other node in the network.
 Routing table updates are periodically transmitted.
 To minimize the routing updates, variable sized update packets are used depending
on the number of topological changes.
 Each entry in the table is marked by a sequence number which helps to distinguish
stale routes from new ones, and thereby avoiding loops.
 When a route update with higher sequence number is received, the old route is
replaced. And when there are two different routes exist with same sequence number
the route with better matrix is used.

35. DSDV
DSDV adds two things to distance vector routing –
a) Sequence number that avoid loops
b) Damping- hold advertisement for changes of short duration
Each node periodically transmits update that includes own sequence number and
routing table update.
Node also send routing table update for important link changes.
When two to a destination received from two different neighbors –
a) Chose the one with greatest destination sequence number
b) If equal chose the smaller metric (hop count)

36. DSDV Table structure
Sequence Number- sequence number originated from destination number and it
ensures loop freeness.
Install time –when entry was made (Used to delete stale entry from the table)
Stable Data -Pointer to a table holding information on how stable a route is. Used
to damp fluctuations in network.
The main advantage of DSDV protocol is this is loop free through destination
sequence number and there is no latency caused by route discovery. But it has
overhead issue because most routing information is never used.
Destination Next Metric Seq. Nr Install Time Stable Data
A A 0 A-550 001000 Ptr_A
B B 1 B-102 001200 Ptr_B
C B 3 C-588 001200 Ptr_C
D B 4 D-312 001200 Ptr_D

37. Proposed System-Mobi Cluster
Mobile Sink
Trajectory
Base Sta on 1 Base Sta on 2
Mobile Collector 1 Mobile Collector 2
Cluster
Cluster Head
Sensor Nodes
Polling Point/Rendezvous Node

38. System Flow Diagram-

39. Mobi-Cluster Protocol
Concept-
• Mobi-cluster protocol helps to ensures delivery of data even through multi-hop transfers from source
sensor nodes located far from the mobile sink trajectories.
• Building hierarchical cluster structures comprising neighbor sensor node to increase the performance
of intra-cluster data filtering and minimize the data relaying overhead.
• Emphasis is given on selecting the appropriate polling points among Sensor nodes located in the
periphery of the sensor islands
(so that they remain within the range of MSs for sufficient time and they buffer data from balanced-
sized groups of source SNs)
Five stages of Mobi-Cluster Protocol-
1.Cluster Head Selection
2. Polling point selection
3. Cluster Head attachment to Polling points
4. Data Aggregation and forwarding to Polling points
5. Communication between Poling point and Mobile collector(data)

40. Clustering Mechanism
Mobi-Cluster Protocol
2 3 4 51
Ini al 3 Phase are-Set up Phase Last two phases are steady phase
In Setup phase mobile sink complete a single trip
while broadcas ng beacon message periodically .
Sensor in the Network used this ‘Beacon’ message to
determine number of important parameter for
protocol opera on
In steady Phase sensor data rou nely gathered
and sent to mobile sink. This phase includes
reselec on of Rendezvous nodes and local re-
clustering . Local Re-Clustering performed when
some important nodes suffer from energy
exhaus on condi on

41. Overall Flow-diagram

42. Project Implementation

43. Simulation Procedure
 Implementation is the stage of the project when the theoretical
design is turned out into a working system. Thus it can be
considered to be the most critical stage in achieving a successful
new system and in giving the user, confidence that the new
system will work and be effective.
 The implementation stage involves careful planning,
investigation of the existing system and it’s constraints on
implementation, designing of methods to achieve changeover
and evaluation of changeover methods. The process of putting
the developed system in actual use is called system
implementation.
 Implementation is the final phase. It involves user training,
system testing and successful running of developed system.

45. Simulation
NS-2 Features
 It is a discrete event simulator that is object oriented
 C++ event scheduler is implemented in the back end
 OTCL is implemented in front end
 NS-2 can be used on UNIX as well Windows operating system(
with Cygwin)

46. Layered Architecture of NS-2
Simula on
Scenario 1 2
Set ns_ [new Simulator]
Set node_(0) [$ns_node]
Set node_(1) [$ns_node]
C++
Implementa on
Class MobileNode :public Node
{
Friend class posi on handler;
Public:
MobileNode ();
}
Network scheduler
and network
component are
implemented by c++
Layered Architecture of NS2 ( Network Simulator)

47. Future Approach- Enhance Data Aggregation strategy (Using Remote Agent)

48. 1. PDR
2. Throughput
3. Residual
Energy
4. Delay
COMPARISON BASED ANALYSIS5

49. PDR ( Packet Delivery Ratio)-
PDR= No of packet received by destination / No of packet sent by content based source
0.00%
20.00%
40.00%
60.00%
80.00%
100.00%
AODV DSDV
PDR
AODV
DSDV

50. Total Energy Consumption
450
500
550
600
650
AODV DSDV
Total Energy Consumption (Kbps)
AODV
DSDV

51. Throughput
Throughput calculation provides information about successful data delivery from a
receiver to a sender over communication stream; this communication steam can be either
logical or physical link .The data transmission calculated in bits per second or kilobits per
second. For efficient network a routing protocol with higher throughput is desirable
AODV DSDV

52. References-
 http://www.mathcs.emory.edu/~cheung/Courses/558-old/Syllabus/90-NS/4-
Wireless/intro.html
 http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.91.4781&rep=rep1&type=p
df
 http://ww2.cs.mu.oz.au/~egemen/lncs08.pdf
 http://www.computer.org/csdl/proceedings/anss/2007/2814/00/28140060-abs.html
 http://dgavalas.ct.aegean.gr/en/iframe_files/papers/2009/AdHoc-NOW%272009.pdf
 http://www.ijettcs.org/Volume1Issue2/IJETTCS-2012-08-23-087.pdf
 http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4224182
 http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=06360577
 http://en.wikipedia.org/wiki/Sensor_node
 http://www.me.utexas.edu/~jensen/exercises/mst_spt/mst_demo/mst1.html
 http://dgavalas.ct.aegean.gr/en/iframe_files/papers/2009/Clustering-chapter.pdf
 http://www.ijettcs.org/Volume1Issue2/IJETTCS-2012-08-23-087.pdf
 http://www.ipcsit.com/vol6/57-E022.pdf
 http://shodhganga.inflibnet.ac.in/bitstream/10603/4106/13/13_chapter%205.pdf

53. References-
 Rendezvous Planning In Wireless Sensor Networks With Mobile Elements
Guoliang Xing, Member, IEEE, Tian Wang, Student Member, IEEE, Zhihui Xie, and
Weijia Jia, Senior Member, IEEE
 Sencar: An Energy-Efficient Data Gathering Mechanism For Large-Scale Multi-Hop Sensor Networks
Ming Ma, Student Member, IEEE, and Yuanyuan Yang, Senior Member, IEEE
 Energy-Efficient Mobile Data Collection In Wireless Sensor Networks With Delay Reduction Using Wireless
Communication
Arun K. Kumar and Krishna M. Sivalingam Dept. of Computer Science and Engineering,
 Mobile Element Scheduling with Dynamic Deadlines
Arun A. Somasundara, Aditya Ramamoorthy, Member, IEEE, and
Mani B. Srivastava, Senior Member, IEEE
 Adaptive Sink Mobility in Event-Driven Densely Deployed Wireless Sensor Networks
Zoltán Vincze1, Dorottya Vass1, Rolland Vida1, Attila Vidács1 and András Telcs2
 Optimal Speed Control of Mobile Node for Data Collection in Sensor Networks
Ryo Sugihara, Student Member, IEEE, and Rajesh K. Gupta, Fellow, IEEE
 Joint Mobility and Routing for Lifetime Elongation in Wireless Sensor Networks
Jun Luo Jean-Pierre Hubaux
 Clustering in Wireless Sensor Networks
Basilis Mamalis, Damianos Gavalas, Charalampos Konstantopoulos, and Grammati Pantziou
 Prolonging the Lifetime of Wireless Sensor Networks via Unequal Clustering
Stanislava Soro and Wendi B. Heinzelman

54. Questions